This patch removes the process grouping code from the cpusets code, instead hooking it into the generic container system. This temporarily adds cpuset-specific code in kernel/container.c, which is removed by the next patch in the series. Signed-off-by: Paul Menage --- Documentation/cpusets.txt | 80 +- fs/super.c | 5 include/linux/container.h | 7 include/linux/cpuset.h | 25 include/linux/fs.h | 2 include/linux/sched.h | 4 init/Kconfig | 19 kernel/container.c | 105 +++ kernel/cpuset.c | 1321 +++++----------------------------------------- kernel/exit.c | 2 kernel/fork.c | 7 mm/oom_kill.c | 6 12 files changed, 317 insertions(+), 1266 deletions(-) Index: container-2.6.19-rc2/include/linux/container.h =================================================================== --- container-2.6.19-rc2.orig/include/linux/container.h +++ container-2.6.19-rc2/include/linux/container.h @@ -47,6 +47,10 @@ struct container { struct container *parent; /* my parent */ struct dentry *dentry; /* container fs entry */ + +#ifdef CONFIG_CPUSETS + struct cpuset *cpuset; +#endif }; /* struct cftype: @@ -79,6 +83,9 @@ struct cftype { int container_add_file(struct container *cont, const struct cftype *cft); int container_is_removed(const struct container *cont); +#ifdef CONFIG_CPUSETS_LEGACY_API +void container_set_release_agent_path(const char *path); +#endif #else /* !CONFIG_CONTAINERS */ Index: container-2.6.19-rc2/include/linux/cpuset.h =================================================================== --- container-2.6.19-rc2.orig/include/linux/cpuset.h +++ container-2.6.19-rc2/include/linux/cpuset.h @@ -11,16 +11,15 @@ #include #include #include +#include #ifdef CONFIG_CPUSETS -extern int number_of_cpusets; /* How many cpusets are defined in system? */ +extern int number_of_cpusets; /* How many cpusets are defined in system? */ extern int cpuset_init_early(void); extern int cpuset_init(void); extern void cpuset_init_smp(void); -extern void cpuset_fork(struct task_struct *p); -extern void cpuset_exit(struct task_struct *p); extern cpumask_t cpuset_cpus_allowed(struct task_struct *p); extern nodemask_t cpuset_mems_allowed(struct task_struct *p); void cpuset_init_current_mems_allowed(void); @@ -47,10 +46,6 @@ extern void __cpuset_memory_pressure_bum extern struct file_operations proc_cpuset_operations; extern char *cpuset_task_status_allowed(struct task_struct *task, char *buffer); - -extern void cpuset_lock(void); -extern void cpuset_unlock(void); - extern int cpuset_mem_spread_node(void); static inline int cpuset_do_page_mem_spread(void) @@ -65,13 +60,22 @@ static inline int cpuset_do_slab_mem_spr extern void cpuset_track_online_nodes(void); +extern int cpuset_can_attach_task(struct container *cont, + struct task_struct *tsk); +extern void cpuset_attach_task(struct container *cont, + struct task_struct *tsk); +extern void cpuset_post_attach_task(struct container *cont, + struct container *oldcont, + struct task_struct *tsk); +extern int cpuset_populate_dir(struct container *cont); +extern int cpuset_create(struct container *cont); +extern void cpuset_destroy(struct container *cont); + #else /* !CONFIG_CPUSETS */ static inline int cpuset_init_early(void) { return 0; } static inline int cpuset_init(void) { return 0; } static inline void cpuset_init_smp(void) {} -static inline void cpuset_fork(struct task_struct *p) {} -static inline void cpuset_exit(struct task_struct *p) {} static inline cpumask_t cpuset_cpus_allowed(struct task_struct *p) { @@ -110,9 +114,6 @@ static inline char *cpuset_task_status_a return buffer; } -static inline void cpuset_lock(void) {} -static inline void cpuset_unlock(void) {} - static inline int cpuset_mem_spread_node(void) { return 0; Index: container-2.6.19-rc2/kernel/exit.c =================================================================== --- container-2.6.19-rc2.orig/kernel/exit.c +++ container-2.6.19-rc2/kernel/exit.c @@ -29,7 +29,6 @@ #include #include #include -#include #include #include #include @@ -922,7 +921,6 @@ fastcall NORET_TYPE void do_exit(long co __exit_files(tsk); __exit_fs(tsk); exit_thread(); - cpuset_exit(tsk); container_exit(tsk); exit_keys(tsk); Index: container-2.6.19-rc2/kernel/fork.c =================================================================== --- container-2.6.19-rc2.orig/kernel/fork.c +++ container-2.6.19-rc2/kernel/fork.c @@ -30,7 +30,6 @@ #include #include #include -#include #include #include #include @@ -1055,13 +1054,12 @@ static struct task_struct *copy_process( p->io_wait = NULL; p->audit_context = NULL; container_fork(p); - cpuset_fork(p); #ifdef CONFIG_NUMA p->mempolicy = mpol_copy(p->mempolicy); if (IS_ERR(p->mempolicy)) { retval = PTR_ERR(p->mempolicy); p->mempolicy = NULL; - goto bad_fork_cleanup_cpuset; + goto bad_fork_cleanup_container; } mpol_fix_fork_child_flag(p); #endif @@ -1287,9 +1285,8 @@ bad_fork_cleanup_security: bad_fork_cleanup_policy: #ifdef CONFIG_NUMA mpol_free(p->mempolicy); -bad_fork_cleanup_cpuset: +bad_fork_cleanup_container: #endif - cpuset_exit(p); container_exit(p); bad_fork_cleanup_delays_binfmt: delayacct_tsk_free(p); Index: container-2.6.19-rc2/kernel/container.c =================================================================== --- container-2.6.19-rc2.orig/kernel/container.c +++ container-2.6.19-rc2/kernel/container.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include @@ -92,6 +93,18 @@ static struct container top_container = .children = LIST_HEAD_INIT(top_container.children), }; +/* The path to use for release notifications. No locking between + * setting and use - so if userspace updates this while subcontainers + * exist, you could miss a notification */ +static char release_agent_path[PATH_MAX] = "/sbin/container_release_agent"; + +void container_set_release_agent_path(const char *path) +{ + container_manage_lock(); + strcpy(release_agent_path, path); + container_manage_unlock(); +} + static struct vfsmount *container_mount; static struct super_block *container_sb; @@ -397,7 +410,7 @@ static void container_release_agent(cons return; i = 0; - argv[i++] = "/sbin/container_release_agent"; + argv[i++] = release_agent_path; argv[i++] = (char *)pathbuf; argv[i] = NULL; @@ -438,6 +451,7 @@ static void check_for_release(struct con buf = kmalloc(PAGE_SIZE, GFP_KERNEL); if (!buf) return; + if (container_path(cont, buf, PAGE_SIZE) < 0) kfree(buf); else @@ -486,7 +500,7 @@ static int attach_task(struct container pid_t pid; struct task_struct *tsk; struct container *oldcont; - int retval; + int retval = 0; if (sscanf(pidbuf, "%d", &pid) != 1) return -EIO; @@ -513,7 +527,9 @@ static int attach_task(struct container get_task_struct(tsk); } - retval = security_task_setscheduler(tsk, 0, NULL); +#ifdef CONFIG_CPUSETS + retval = cpuset_can_attach_task(cont, tsk); +#endif if (retval) { put_task_struct(tsk); return retval; @@ -533,8 +549,16 @@ static int attach_task(struct container rcu_assign_pointer(tsk->container, cont); task_unlock(tsk); +#ifdef CONFIG_CPUSETS + cpuset_attach_task(cont, tsk); +#endif + mutex_unlock(&callback_mutex); +#ifdef CONFIG_CPUSETS + cpuset_post_attach_task(cont, oldcont, tsk); +#endif + put_task_struct(tsk); synchronize_rcu(); if (atomic_dec_and_test(&oldcont->count)) @@ -549,6 +573,7 @@ typedef enum { FILE_DIR, FILE_NOTIFY_ON_RELEASE, FILE_TASKLIST, + FILE_RELEASE_AGENT, } container_filetype_t; static ssize_t container_common_file_write(struct container *cont, @@ -562,8 +587,7 @@ static ssize_t container_common_file_wri char *pathbuf = NULL; int retval = 0; - /* Crude upper limit on largest legitimate cpulist user might write. */ - if (nbytes > 100 + 6 * NR_CPUS) + if (nbytes >= PATH_MAX) return -E2BIG; /* +1 for nul-terminator */ @@ -590,6 +614,20 @@ static ssize_t container_common_file_wri case FILE_TASKLIST: retval = attach_task(cont, buffer, &pathbuf); break; + case FILE_RELEASE_AGENT: + { + if (nbytes < sizeof(release_agent_path)) { + /* We never write anything other than '\0' + * into the last char of release_agent_path, + * so it always remains a NUL-terminated + * string */ + strncpy(release_agent_path, buffer, nbytes); + release_agent_path[nbytes] = 0; + } else { + retval = -ENOSPC; + } + break; + } default: retval = -EINVAL; goto out2; @@ -643,6 +681,17 @@ static ssize_t container_common_file_rea case FILE_NOTIFY_ON_RELEASE: *s++ = notify_on_release(cont) ? '1' : '0'; break; + case FILE_RELEASE_AGENT: + { + size_t n; + container_manage_lock(); + n = strnlen(release_agent_path, sizeof(release_agent_path)); + n = min(n, (size_t) PAGE_SIZE); + strncpy(s, release_agent_path, n); + container_manage_unlock(); + s += n; + break; + } default: retval = -EINVAL; goto out; @@ -978,6 +1027,13 @@ static struct cftype cft_notify_on_relea .private = FILE_NOTIFY_ON_RELEASE, }; +static struct cftype cft_release_agent = { + .name = "release_agent", + .read = container_common_file_read, + .write = container_common_file_write, + .private = FILE_RELEASE_AGENT, +}; + static int container_populate_dir(struct container *cont) { int err; @@ -986,6 +1042,13 @@ static int container_populate_dir(struct return err; if ((err = container_add_file(cont, &cft_tasks)) < 0) return err; + if ((cont == &top_container) && + (err = container_add_file(cont, &cft_release_agent)) < 0) + return err; +#ifdef CONFIG_CPUSETS + if ((err = cpuset_populate_dir(cont)) < 0) + return err; +#endif return 0; } @@ -1017,6 +1080,12 @@ static long container_create(struct cont cont->parent = parent; +#ifdef CONFIG_CPUSETS + err = cpuset_create(cont); + if (err) + goto err_unlock_free; +#endif + mutex_lock(&callback_mutex); list_add(&cont->sibling, &cont->parent->children); number_of_containers++; @@ -1038,11 +1107,14 @@ static long container_create(struct cont return 0; err_remove: +#ifdef CONFIG_CPUSETS + cpuset_destroy(cont); +#endif mutex_lock(&callback_mutex); list_del(&cont->sibling); number_of_containers--; mutex_unlock(&callback_mutex); - + err_unlock_free: mutex_unlock(&manage_mutex); kfree(cont); return err; @@ -1097,6 +1169,9 @@ static int container_rmdir(struct inode dput(d); number_of_containers--; mutex_unlock(&callback_mutex); +#ifdef CONFIG_CPUSETS + cpuset_destroy(cont); +#endif if (list_empty(&parent->children)) check_for_release(parent, &pathbuf); mutex_unlock(&manage_mutex); @@ -1283,6 +1358,24 @@ void container_unlock(void) mutex_unlock(&callback_mutex); } +void container_manage_lock(void) +{ + mutex_lock(&manage_mutex); +} + +/** + * container_manage_unlock - release lock on container changes + * + * Undo the lock taken in a previous container_manage_lock() call. + */ + +void container_manage_unlock(void) +{ + mutex_unlock(&manage_mutex); +} + + + /* * proc_container_show() * - Print tasks container path into seq_file. Index: container-2.6.19-rc2/kernel/cpuset.c =================================================================== --- container-2.6.19-rc2.orig/kernel/cpuset.c +++ container-2.6.19-rc2/kernel/cpuset.c @@ -54,8 +54,6 @@ #include #include -#define CPUSET_SUPER_MAGIC 0x27e0eb - /* * Tracks how many cpusets are currently defined in system. * When there is only one cpuset (the root cpuset) we can @@ -77,20 +75,8 @@ struct cpuset { cpumask_t cpus_allowed; /* CPUs allowed to tasks in cpuset */ nodemask_t mems_allowed; /* Memory Nodes allowed to tasks */ - /* - * Count is atomic so can incr (fork) or decr (exit) without a lock. - */ - atomic_t count; /* count tasks using this cpuset */ - - /* - * We link our 'sibling' struct into our parents 'children'. - * Our children link their 'sibling' into our 'children'. - */ - struct list_head sibling; /* my parents children */ - struct list_head children; /* my children */ - + struct container *container; /* Task container */ struct cpuset *parent; /* my parent */ - struct dentry *dentry; /* cpuset fs entry */ /* * Copy of global cpuset_mems_generation as of the most @@ -106,8 +92,6 @@ typedef enum { CS_CPU_EXCLUSIVE, CS_MEM_EXCLUSIVE, CS_MEMORY_MIGRATE, - CS_REMOVED, - CS_NOTIFY_ON_RELEASE, CS_SPREAD_PAGE, CS_SPREAD_SLAB, } cpuset_flagbits_t; @@ -123,16 +107,6 @@ static inline int is_mem_exclusive(const return test_bit(CS_MEM_EXCLUSIVE, &cs->flags); } -static inline int is_removed(const struct cpuset *cs) -{ - return test_bit(CS_REMOVED, &cs->flags); -} - -static inline int notify_on_release(const struct cpuset *cs) -{ - return test_bit(CS_NOTIFY_ON_RELEASE, &cs->flags); -} - static inline int is_memory_migrate(const struct cpuset *cs) { return test_bit(CS_MEMORY_MIGRATE, &cs->flags); @@ -173,388 +147,33 @@ static struct cpuset top_cpuset = { .flags = ((1 << CS_CPU_EXCLUSIVE) | (1 << CS_MEM_EXCLUSIVE)), .cpus_allowed = CPU_MASK_ALL, .mems_allowed = NODE_MASK_ALL, - .count = ATOMIC_INIT(0), - .sibling = LIST_HEAD_INIT(top_cpuset.sibling), - .children = LIST_HEAD_INIT(top_cpuset.children), -}; - -static struct vfsmount *cpuset_mount; -static struct super_block *cpuset_sb; - -/* - * We have two global cpuset mutexes below. They can nest. - * It is ok to first take manage_mutex, then nest callback_mutex. We also - * require taking task_lock() when dereferencing a tasks cpuset pointer. - * See "The task_lock() exception", at the end of this comment. - * - * A task must hold both mutexes to modify cpusets. If a task - * holds manage_mutex, then it blocks others wanting that mutex, - * ensuring that it is the only task able to also acquire callback_mutex - * and be able to modify cpusets. It can perform various checks on - * the cpuset structure first, knowing nothing will change. It can - * also allocate memory while just holding manage_mutex. While it is - * performing these checks, various callback routines can briefly - * acquire callback_mutex to query cpusets. Once it is ready to make - * the changes, it takes callback_mutex, blocking everyone else. - * - * Calls to the kernel memory allocator can not be made while holding - * callback_mutex, as that would risk double tripping on callback_mutex - * from one of the callbacks into the cpuset code from within - * __alloc_pages(). - * - * If a task is only holding callback_mutex, then it has read-only - * access to cpusets. - * - * The task_struct fields mems_allowed and mems_generation may only - * be accessed in the context of that task, so require no locks. - * - * Any task can increment and decrement the count field without lock. - * So in general, code holding manage_mutex or callback_mutex can't rely - * on the count field not changing. However, if the count goes to - * zero, then only attach_task(), which holds both mutexes, can - * increment it again. Because a count of zero means that no tasks - * are currently attached, therefore there is no way a task attached - * to that cpuset can fork (the other way to increment the count). - * So code holding manage_mutex or callback_mutex can safely assume that - * if the count is zero, it will stay zero. Similarly, if a task - * holds manage_mutex or callback_mutex on a cpuset with zero count, it - * knows that the cpuset won't be removed, as cpuset_rmdir() needs - * both of those mutexes. - * - * The cpuset_common_file_write handler for operations that modify - * the cpuset hierarchy holds manage_mutex across the entire operation, - * single threading all such cpuset modifications across the system. - * - * The cpuset_common_file_read() handlers only hold callback_mutex across - * small pieces of code, such as when reading out possibly multi-word - * cpumasks and nodemasks. - * - * The fork and exit callbacks cpuset_fork() and cpuset_exit(), don't - * (usually) take either mutex. These are the two most performance - * critical pieces of code here. The exception occurs on cpuset_exit(), - * when a task in a notify_on_release cpuset exits. Then manage_mutex - * is taken, and if the cpuset count is zero, a usermode call made - * to /sbin/cpuset_release_agent with the name of the cpuset (path - * relative to the root of cpuset file system) as the argument. - * - * A cpuset can only be deleted if both its 'count' of using tasks - * is zero, and its list of 'children' cpusets is empty. Since all - * tasks in the system use _some_ cpuset, and since there is always at - * least one task in the system (init), therefore, top_cpuset - * always has either children cpusets and/or using tasks. So we don't - * need a special hack to ensure that top_cpuset cannot be deleted. - * - * The above "Tale of Two Semaphores" would be complete, but for: - * - * The task_lock() exception - * - * The need for this exception arises from the action of attach_task(), - * which overwrites one tasks cpuset pointer with another. It does - * so using both mutexes, however there are several performance - * critical places that need to reference task->cpuset without the - * expense of grabbing a system global mutex. Therefore except as - * noted below, when dereferencing or, as in attach_task(), modifying - * a tasks cpuset pointer we use task_lock(), which acts on a spinlock - * (task->alloc_lock) already in the task_struct routinely used for - * such matters. - * - * P.S. One more locking exception. RCU is used to guard the - * update of a tasks cpuset pointer by attach_task() and the - * access of task->cpuset->mems_generation via that pointer in - * the routine cpuset_update_task_memory_state(). - */ - -static DEFINE_MUTEX(manage_mutex); -static DEFINE_MUTEX(callback_mutex); - -/* - * A couple of forward declarations required, due to cyclic reference loop: - * cpuset_mkdir -> cpuset_create -> cpuset_populate_dir -> cpuset_add_file - * -> cpuset_create_file -> cpuset_dir_inode_operations -> cpuset_mkdir. - */ - -static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode); -static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry); - -static struct backing_dev_info cpuset_backing_dev_info = { - .ra_pages = 0, /* No readahead */ - .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, -}; - -static struct inode *cpuset_new_inode(mode_t mode) -{ - struct inode *inode = new_inode(cpuset_sb); - - if (inode) { - inode->i_mode = mode; - inode->i_uid = current->fsuid; - inode->i_gid = current->fsgid; - inode->i_blocks = 0; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; - inode->i_mapping->backing_dev_info = &cpuset_backing_dev_info; - } - return inode; -} - -static void cpuset_diput(struct dentry *dentry, struct inode *inode) -{ - /* is dentry a directory ? if so, kfree() associated cpuset */ - if (S_ISDIR(inode->i_mode)) { - struct cpuset *cs = dentry->d_fsdata; - BUG_ON(!(is_removed(cs))); - kfree(cs); - } - iput(inode); -} - -static struct dentry_operations cpuset_dops = { - .d_iput = cpuset_diput, -}; - -static struct dentry *cpuset_get_dentry(struct dentry *parent, const char *name) -{ - struct dentry *d = lookup_one_len(name, parent, strlen(name)); - if (!IS_ERR(d)) - d->d_op = &cpuset_dops; - return d; -} - -static void remove_dir(struct dentry *d) -{ - struct dentry *parent = dget(d->d_parent); - - d_delete(d); - simple_rmdir(parent->d_inode, d); - dput(parent); -} - -/* - * NOTE : the dentry must have been dget()'ed - */ -static void cpuset_d_remove_dir(struct dentry *dentry) -{ - struct list_head *node; - - spin_lock(&dcache_lock); - node = dentry->d_subdirs.next; - while (node != &dentry->d_subdirs) { - struct dentry *d = list_entry(node, struct dentry, d_u.d_child); - list_del_init(node); - if (d->d_inode) { - d = dget_locked(d); - spin_unlock(&dcache_lock); - d_delete(d); - simple_unlink(dentry->d_inode, d); - dput(d); - spin_lock(&dcache_lock); - } - node = dentry->d_subdirs.next; - } - list_del_init(&dentry->d_u.d_child); - spin_unlock(&dcache_lock); - remove_dir(dentry); -} - -static struct super_operations cpuset_ops = { - .statfs = simple_statfs, - .drop_inode = generic_delete_inode, }; -static int cpuset_fill_super(struct super_block *sb, void *unused_data, - int unused_silent) -{ - struct inode *inode; - struct dentry *root; - - sb->s_blocksize = PAGE_CACHE_SIZE; - sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = CPUSET_SUPER_MAGIC; - sb->s_op = &cpuset_ops; - cpuset_sb = sb; - - inode = cpuset_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR); - if (inode) { - inode->i_op = &simple_dir_inode_operations; - inode->i_fop = &simple_dir_operations; - /* directories start off with i_nlink == 2 (for "." entry) */ - inc_nlink(inode); - } else { - return -ENOMEM; - } - - root = d_alloc_root(inode); - if (!root) { - iput(inode); - return -ENOMEM; - } - sb->s_root = root; - return 0; -} - +#ifdef CONFIG_CPUSETS_LEGACY_API +/* This is ugly, but preserves the userspace API for existing cpuset + * users. If someone tries to mount the "cpuset" filesystem, we + * silently switch it to mount "container" instead */ static int cpuset_get_sb(struct file_system_type *fs_type, int flags, const char *unused_dev_name, void *data, struct vfsmount *mnt) { - return get_sb_single(fs_type, flags, data, cpuset_fill_super, mnt); + struct file_system_type *container_fs = get_fs_type("container"); + int ret = -ENODEV; + container_set_release_agent_path("/sbin/cpuset_release_agent"); + if (container_fs) { + ret = container_fs->get_sb(container_fs, flags, + unused_dev_name, + data, mnt); + put_filesystem(container_fs); + } + return ret; } static struct file_system_type cpuset_fs_type = { .name = "cpuset", .get_sb = cpuset_get_sb, - .kill_sb = kill_litter_super, -}; - -/* struct cftype: - * - * The files in the cpuset filesystem mostly have a very simple read/write - * handling, some common function will take care of it. Nevertheless some cases - * (read tasks) are special and therefore I define this structure for every - * kind of file. - * - * - * When reading/writing to a file: - * - the cpuset to use in file->f_dentry->d_parent->d_fsdata - * - the 'cftype' of the file is file->f_dentry->d_fsdata - */ - -struct cftype { - char *name; - int private; - int (*open) (struct inode *inode, struct file *file); - ssize_t (*read) (struct file *file, char __user *buf, size_t nbytes, - loff_t *ppos); - int (*write) (struct file *file, const char __user *buf, size_t nbytes, - loff_t *ppos); - int (*release) (struct inode *inode, struct file *file); }; - -static inline struct cpuset *__d_cs(struct dentry *dentry) -{ - return dentry->d_fsdata; -} - -static inline struct cftype *__d_cft(struct dentry *dentry) -{ - return dentry->d_fsdata; -} - -/* - * Call with manage_mutex held. Writes path of cpuset into buf. - * Returns 0 on success, -errno on error. - */ - -static int cpuset_path(const struct cpuset *cs, char *buf, int buflen) -{ - char *start; - - start = buf + buflen; - - *--start = '\0'; - for (;;) { - int len = cs->dentry->d_name.len; - if ((start -= len) < buf) - return -ENAMETOOLONG; - memcpy(start, cs->dentry->d_name.name, len); - cs = cs->parent; - if (!cs) - break; - if (!cs->parent) - continue; - if (--start < buf) - return -ENAMETOOLONG; - *start = '/'; - } - memmove(buf, start, buf + buflen - start); - return 0; -} - -/* - * Notify userspace when a cpuset is released, by running - * /sbin/cpuset_release_agent with the name of the cpuset (path - * relative to the root of cpuset file system) as the argument. - * - * Most likely, this user command will try to rmdir this cpuset. - * - * This races with the possibility that some other task will be - * attached to this cpuset before it is removed, or that some other - * user task will 'mkdir' a child cpuset of this cpuset. That's ok. - * The presumed 'rmdir' will fail quietly if this cpuset is no longer - * unused, and this cpuset will be reprieved from its death sentence, - * to continue to serve a useful existence. Next time it's released, - * we will get notified again, if it still has 'notify_on_release' set. - * - * The final arg to call_usermodehelper() is 0, which means don't - * wait. The separate /sbin/cpuset_release_agent task is forked by - * call_usermodehelper(), then control in this thread returns here, - * without waiting for the release agent task. We don't bother to - * wait because the caller of this routine has no use for the exit - * status of the /sbin/cpuset_release_agent task, so no sense holding - * our caller up for that. - * - * When we had only one cpuset mutex, we had to call this - * without holding it, to avoid deadlock when call_usermodehelper() - * allocated memory. With two locks, we could now call this while - * holding manage_mutex, but we still don't, so as to minimize - * the time manage_mutex is held. - */ - -static void cpuset_release_agent(const char *pathbuf) -{ - char *argv[3], *envp[3]; - int i; - - if (!pathbuf) - return; - - i = 0; - argv[i++] = "/sbin/cpuset_release_agent"; - argv[i++] = (char *)pathbuf; - argv[i] = NULL; - - i = 0; - /* minimal command environment */ - envp[i++] = "HOME=/"; - envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; - envp[i] = NULL; - - call_usermodehelper(argv[0], argv, envp, 0); - kfree(pathbuf); -} - -/* - * Either cs->count of using tasks transitioned to zero, or the - * cs->children list of child cpusets just became empty. If this - * cs is notify_on_release() and now both the user count is zero and - * the list of children is empty, prepare cpuset path in a kmalloc'd - * buffer, to be returned via ppathbuf, so that the caller can invoke - * cpuset_release_agent() with it later on, once manage_mutex is dropped. - * Call here with manage_mutex held. - * - * This check_for_release() routine is responsible for kmalloc'ing - * pathbuf. The above cpuset_release_agent() is responsible for - * kfree'ing pathbuf. The caller of these routines is responsible - * for providing a pathbuf pointer, initialized to NULL, then - * calling check_for_release() with manage_mutex held and the address - * of the pathbuf pointer, then dropping manage_mutex, then calling - * cpuset_release_agent() with pathbuf, as set by check_for_release(). - */ - -static void check_for_release(struct cpuset *cs, char **ppathbuf) -{ - if (notify_on_release(cs) && atomic_read(&cs->count) == 0 && - list_empty(&cs->children)) { - char *buf; - - buf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - return; - if (cpuset_path(cs, buf, PAGE_SIZE) < 0) - kfree(buf); - else - *ppathbuf = buf; - } -} - +#endif /* CONFIG_CPUSETS_LEGACY_API */ /* * Return in *pmask the portion of a cpusets's cpus_allowed that * are online. If none are online, walk up the cpuset hierarchy @@ -652,20 +271,20 @@ void cpuset_update_task_memory_state(voi struct task_struct *tsk = current; struct cpuset *cs; - if (tsk->cpuset == &top_cpuset) { + if (tsk->container->cpuset == &top_cpuset) { /* Don't need rcu for top_cpuset. It's never freed. */ my_cpusets_mem_gen = top_cpuset.mems_generation; } else { rcu_read_lock(); - cs = rcu_dereference(tsk->cpuset); + cs = rcu_dereference(tsk->container->cpuset); my_cpusets_mem_gen = cs->mems_generation; rcu_read_unlock(); } if (my_cpusets_mem_gen != tsk->cpuset_mems_generation) { - mutex_lock(&callback_mutex); + container_lock(); task_lock(tsk); - cs = tsk->cpuset; /* Maybe changed when task not locked */ + cs = tsk->container->cpuset; /* Maybe changed when task not locked */ guarantee_online_mems(cs, &tsk->mems_allowed); tsk->cpuset_mems_generation = cs->mems_generation; if (is_spread_page(cs)) @@ -677,7 +296,7 @@ void cpuset_update_task_memory_state(voi else tsk->flags &= ~PF_SPREAD_SLAB; task_unlock(tsk); - mutex_unlock(&callback_mutex); + container_unlock(); mpol_rebind_task(tsk, &tsk->mems_allowed); } } @@ -720,10 +339,12 @@ static int is_cpuset_subset(const struct static int validate_change(const struct cpuset *cur, const struct cpuset *trial) { + struct container *cont; struct cpuset *c, *par; /* Each of our child cpusets must be a subset of us */ - list_for_each_entry(c, &cur->children, sibling) { + list_for_each_entry(cont, &cur->container->children, sibling) { + c = cont->cpuset; if (!is_cpuset_subset(c, trial)) return -EBUSY; } @@ -737,7 +358,8 @@ static int validate_change(const struct return -EACCES; /* If either I or some sibling (!= me) is exclusive, we can't overlap */ - list_for_each_entry(c, &par->children, sibling) { + list_for_each_entry(cont, &par->container->children, sibling) { + c = cont->cpuset; if ((is_cpu_exclusive(trial) || is_cpu_exclusive(c)) && c != cur && cpus_intersects(trial->cpus_allowed, c->cpus_allowed)) @@ -767,6 +389,7 @@ static int validate_change(const struct static void update_cpu_domains(struct cpuset *cur) { + struct container *cont; struct cpuset *c, *par = cur->parent; cpumask_t pspan, cspan; @@ -778,7 +401,8 @@ static void update_cpu_domains(struct cp * children */ pspan = par->cpus_allowed; - list_for_each_entry(c, &par->children, sibling) { + list_for_each_entry(cont, &par->container->children, sibling) { + c = cont->cpuset; if (is_cpu_exclusive(c)) cpus_andnot(pspan, pspan, c->cpus_allowed); } @@ -795,7 +419,8 @@ static void update_cpu_domains(struct cp * Get all cpus from current cpuset's cpus_allowed not part * of exclusive children */ - list_for_each_entry(c, &cur->children, sibling) { + list_for_each_entry(cont, &cur->container->children, sibling) { + c = cont->cpuset; if (is_cpu_exclusive(c)) cpus_andnot(cspan, cspan, c->cpus_allowed); } @@ -830,9 +455,9 @@ static int update_cpumask(struct cpuset if (retval < 0) return retval; cpus_unchanged = cpus_equal(cs->cpus_allowed, trialcs.cpus_allowed); - mutex_lock(&callback_mutex); + container_lock(); cs->cpus_allowed = trialcs.cpus_allowed; - mutex_unlock(&callback_mutex); + container_unlock(); if (is_cpu_exclusive(cs) && !cpus_unchanged) update_cpu_domains(cs); return 0; @@ -876,15 +501,15 @@ static void cpuset_migrate_mm(struct mm_ cpuset_update_task_memory_state(); - mutex_lock(&callback_mutex); + container_lock(); tsk->mems_allowed = *to; - mutex_unlock(&callback_mutex); + container_unlock(); do_migrate_pages(mm, from, to, MPOL_MF_MOVE_ALL); - mutex_lock(&callback_mutex); - guarantee_online_mems(tsk->cpuset, &tsk->mems_allowed); - mutex_unlock(&callback_mutex); + container_lock(); + guarantee_online_mems(tsk->container->cpuset, &tsk->mems_allowed); + container_unlock(); } /* @@ -911,12 +536,14 @@ static int update_nodemask(struct cpuset int migrate; int fudge; int retval; + struct container *cont; /* top_cpuset.mems_allowed tracks node_online_map; it's read-only */ if (cs == &top_cpuset) return -EACCES; trialcs = *cs; + cont = cs->container; retval = nodelist_parse(buf, trialcs.mems_allowed); if (retval < 0) goto done; @@ -934,10 +561,10 @@ static int update_nodemask(struct cpuset if (retval < 0) goto done; - mutex_lock(&callback_mutex); + container_lock(); cs->mems_allowed = trialcs.mems_allowed; cs->mems_generation = cpuset_mems_generation++; - mutex_unlock(&callback_mutex); + container_unlock(); set_cpuset_being_rebound(cs); /* causes mpol_copy() rebind */ @@ -953,13 +580,13 @@ static int update_nodemask(struct cpuset * enough mmarray[] w/o using GFP_ATOMIC. */ while (1) { - ntasks = atomic_read(&cs->count); /* guess */ + ntasks = atomic_read(&cs->container->count); /* guess */ ntasks += fudge; mmarray = kmalloc(ntasks * sizeof(*mmarray), GFP_KERNEL); if (!mmarray) goto done; write_lock_irq(&tasklist_lock); /* block fork */ - if (atomic_read(&cs->count) <= ntasks) + if (atomic_read(&cs->container->count) <= ntasks) break; /* got enough */ write_unlock_irq(&tasklist_lock); /* try again */ kfree(mmarray); @@ -976,7 +603,7 @@ static int update_nodemask(struct cpuset "Cpuset mempolicy rebind incomplete.\n"); continue; } - if (p->cpuset != cs) + if (p->container != cont) continue; mm = get_task_mm(p); if (!mm) @@ -1059,15 +686,15 @@ static int update_flag(cpuset_flagbits_t return err; cpu_exclusive_changed = (is_cpu_exclusive(cs) != is_cpu_exclusive(&trialcs)); - mutex_lock(&callback_mutex); + container_lock(); if (turning_on) set_bit(bit, &cs->flags); else clear_bit(bit, &cs->flags); - mutex_unlock(&callback_mutex); + container_unlock(); if (cpu_exclusive_changed) - update_cpu_domains(cs); + update_cpu_domains(cs); return 0; } @@ -1169,85 +796,35 @@ static int fmeter_getrate(struct fmeter return val; } -/* - * Attack task specified by pid in 'pidbuf' to cpuset 'cs', possibly - * writing the path of the old cpuset in 'ppathbuf' if it needs to be - * notified on release. - * - * Call holding manage_mutex. May take callback_mutex and task_lock of - * the task 'pid' during call. - */ - -static int attach_task(struct cpuset *cs, char *pidbuf, char **ppathbuf) +int cpuset_can_attach_task(struct container *cont, struct task_struct *tsk) { - pid_t pid; - struct task_struct *tsk; - struct cpuset *oldcs; - cpumask_t cpus; - nodemask_t from, to; - struct mm_struct *mm; - int retval; + struct cpuset *cs = cont->cpuset; - if (sscanf(pidbuf, "%d", &pid) != 1) - return -EIO; if (cpus_empty(cs->cpus_allowed) || nodes_empty(cs->mems_allowed)) return -ENOSPC; - if (pid) { - read_lock(&tasklist_lock); - - tsk = find_task_by_pid(pid); - if (!tsk || tsk->flags & PF_EXITING) { - read_unlock(&tasklist_lock); - return -ESRCH; - } - - get_task_struct(tsk); - read_unlock(&tasklist_lock); - - if ((current->euid) && (current->euid != tsk->uid) - && (current->euid != tsk->suid)) { - put_task_struct(tsk); - return -EACCES; - } - } else { - tsk = current; - get_task_struct(tsk); - } - - retval = security_task_setscheduler(tsk, 0, NULL); - if (retval) { - put_task_struct(tsk); - return retval; - } - - mutex_lock(&callback_mutex); - - task_lock(tsk); - oldcs = tsk->cpuset; - /* - * After getting 'oldcs' cpuset ptr, be sure still not exiting. - * If 'oldcs' might be the top_cpuset due to the_top_cpuset_hack - * then fail this attach_task(), to avoid breaking top_cpuset.count. - */ - if (tsk->flags & PF_EXITING) { - task_unlock(tsk); - mutex_unlock(&callback_mutex); - put_task_struct(tsk); - return -ESRCH; - } - atomic_inc(&cs->count); - rcu_assign_pointer(tsk->cpuset, cs); - task_unlock(tsk); + return security_task_setscheduler(tsk, 0, NULL); +} +void cpuset_attach_task(struct container *cont, struct task_struct *tsk) +{ + cpumask_t cpus; + struct cpuset *cs = cont->cpuset; guarantee_online_cpus(cs, &cpus); set_cpus_allowed(tsk, cpus); +} + +void cpuset_post_attach_task(struct container *cont, + struct container *oldcont, + struct task_struct *tsk) +{ + nodemask_t from, to; + struct mm_struct *mm; + struct cpuset *cs = cont->cpuset; + struct cpuset *oldcs = oldcont->cpuset; from = oldcs->mems_allowed; to = cs->mems_allowed; - - mutex_unlock(&callback_mutex); - mm = get_task_mm(tsk); if (mm) { mpol_rebind_mm(mm, &to); @@ -1256,39 +833,31 @@ static int attach_task(struct cpuset *cs mmput(mm); } - put_task_struct(tsk); - synchronize_rcu(); - if (atomic_dec_and_test(&oldcs->count)) - check_for_release(oldcs, ppathbuf); - return 0; } /* The various types of files and directories in a cpuset file system */ typedef enum { - FILE_ROOT, - FILE_DIR, FILE_MEMORY_MIGRATE, FILE_CPULIST, FILE_MEMLIST, FILE_CPU_EXCLUSIVE, FILE_MEM_EXCLUSIVE, - FILE_NOTIFY_ON_RELEASE, FILE_MEMORY_PRESSURE_ENABLED, FILE_MEMORY_PRESSURE, FILE_SPREAD_PAGE, FILE_SPREAD_SLAB, - FILE_TASKLIST, } cpuset_filetype_t; -static ssize_t cpuset_common_file_write(struct file *file, const char __user *userbuf, +static ssize_t cpuset_common_file_write(struct container *cont, + struct cftype *cft, + struct file *file, + const char __user *userbuf, size_t nbytes, loff_t *unused_ppos) { - struct cpuset *cs = __d_cs(file->f_dentry->d_parent); - struct cftype *cft = __d_cft(file->f_dentry); + struct cpuset *cs = cont->cpuset; cpuset_filetype_t type = cft->private; char *buffer; - char *pathbuf = NULL; int retval = 0; /* Crude upper limit on largest legitimate cpulist user might write. */ @@ -1305,9 +874,9 @@ static ssize_t cpuset_common_file_write( } buffer[nbytes] = 0; /* nul-terminate */ - mutex_lock(&manage_mutex); + container_manage_lock(); - if (is_removed(cs)) { + if (container_is_removed(cont)) { retval = -ENODEV; goto out2; } @@ -1325,9 +894,6 @@ static ssize_t cpuset_common_file_write( case FILE_MEM_EXCLUSIVE: retval = update_flag(CS_MEM_EXCLUSIVE, cs, buffer); break; - case FILE_NOTIFY_ON_RELEASE: - retval = update_flag(CS_NOTIFY_ON_RELEASE, cs, buffer); - break; case FILE_MEMORY_MIGRATE: retval = update_flag(CS_MEMORY_MIGRATE, cs, buffer); break; @@ -1345,9 +911,6 @@ static ssize_t cpuset_common_file_write( retval = update_flag(CS_SPREAD_SLAB, cs, buffer); cs->mems_generation = cpuset_mems_generation++; break; - case FILE_TASKLIST: - retval = attach_task(cs, buffer, &pathbuf); - break; default: retval = -EINVAL; goto out2; @@ -1356,30 +919,12 @@ static ssize_t cpuset_common_file_write( if (retval == 0) retval = nbytes; out2: - mutex_unlock(&manage_mutex); - cpuset_release_agent(pathbuf); + container_manage_unlock(); out1: kfree(buffer); return retval; } -static ssize_t cpuset_file_write(struct file *file, const char __user *buf, - size_t nbytes, loff_t *ppos) -{ - ssize_t retval = 0; - struct cftype *cft = __d_cft(file->f_dentry); - if (!cft) - return -ENODEV; - - /* special function ? */ - if (cft->write) - retval = cft->write(file, buf, nbytes, ppos); - else - retval = cpuset_common_file_write(file, buf, nbytes, ppos); - - return retval; -} - /* * These ascii lists should be read in a single call, by using a user * buffer large enough to hold the entire map. If read in smaller @@ -1396,9 +941,9 @@ static int cpuset_sprintf_cpulist(char * { cpumask_t mask; - mutex_lock(&callback_mutex); + container_lock(); mask = cs->cpus_allowed; - mutex_unlock(&callback_mutex); + container_unlock(); return cpulist_scnprintf(page, PAGE_SIZE, mask); } @@ -1407,18 +952,20 @@ static int cpuset_sprintf_memlist(char * { nodemask_t mask; - mutex_lock(&callback_mutex); + container_lock(); mask = cs->mems_allowed; - mutex_unlock(&callback_mutex); + container_unlock(); return nodelist_scnprintf(page, PAGE_SIZE, mask); } -static ssize_t cpuset_common_file_read(struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) +static ssize_t cpuset_common_file_read(struct container *cont, + struct cftype *cft, + struct file *file, + char __user *buf, + size_t nbytes, loff_t *ppos) { - struct cftype *cft = __d_cft(file->f_dentry); - struct cpuset *cs = __d_cs(file->f_dentry->d_parent); + struct cpuset *cs = cont->cpuset; cpuset_filetype_t type = cft->private; char *page; ssize_t retval = 0; @@ -1442,9 +989,6 @@ static ssize_t cpuset_common_file_read(s case FILE_MEM_EXCLUSIVE: *s++ = is_mem_exclusive(cs) ? '1' : '0'; break; - case FILE_NOTIFY_ON_RELEASE: - *s++ = notify_on_release(cs) ? '1' : '0'; - break; case FILE_MEMORY_MIGRATE: *s++ = is_memory_migrate(cs) ? '1' : '0'; break; @@ -1472,391 +1016,97 @@ out: return retval; } -static ssize_t cpuset_file_read(struct file *file, char __user *buf, size_t nbytes, - loff_t *ppos) -{ - ssize_t retval = 0; - struct cftype *cft = __d_cft(file->f_dentry); - if (!cft) - return -ENODEV; - - /* special function ? */ - if (cft->read) - retval = cft->read(file, buf, nbytes, ppos); - else - retval = cpuset_common_file_read(file, buf, nbytes, ppos); - - return retval; -} - -static int cpuset_file_open(struct inode *inode, struct file *file) -{ - int err; - struct cftype *cft; - - err = generic_file_open(inode, file); - if (err) - return err; - - cft = __d_cft(file->f_dentry); - if (!cft) - return -ENODEV; - if (cft->open) - err = cft->open(inode, file); - else - err = 0; - - return err; -} - -static int cpuset_file_release(struct inode *inode, struct file *file) -{ - struct cftype *cft = __d_cft(file->f_dentry); - if (cft->release) - return cft->release(inode, file); - return 0; -} - -/* - * cpuset_rename - Only allow simple rename of directories in place. - */ -static int cpuset_rename(struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) -{ - if (!S_ISDIR(old_dentry->d_inode->i_mode)) - return -ENOTDIR; - if (new_dentry->d_inode) - return -EEXIST; - if (old_dir != new_dir) - return -EIO; - return simple_rename(old_dir, old_dentry, new_dir, new_dentry); -} - -static struct file_operations cpuset_file_operations = { - .read = cpuset_file_read, - .write = cpuset_file_write, - .llseek = generic_file_llseek, - .open = cpuset_file_open, - .release = cpuset_file_release, -}; - -static struct inode_operations cpuset_dir_inode_operations = { - .lookup = simple_lookup, - .mkdir = cpuset_mkdir, - .rmdir = cpuset_rmdir, - .rename = cpuset_rename, -}; - -static int cpuset_create_file(struct dentry *dentry, int mode) -{ - struct inode *inode; - - if (!dentry) - return -ENOENT; - if (dentry->d_inode) - return -EEXIST; - - inode = cpuset_new_inode(mode); - if (!inode) - return -ENOMEM; - - if (S_ISDIR(mode)) { - inode->i_op = &cpuset_dir_inode_operations; - inode->i_fop = &simple_dir_operations; - - /* start off with i_nlink == 2 (for "." entry) */ - inc_nlink(inode); - } else if (S_ISREG(mode)) { - inode->i_size = 0; - inode->i_fop = &cpuset_file_operations; - } - - d_instantiate(dentry, inode); - dget(dentry); /* Extra count - pin the dentry in core */ - return 0; -} - -/* - * cpuset_create_dir - create a directory for an object. - * cs: the cpuset we create the directory for. - * It must have a valid ->parent field - * And we are going to fill its ->dentry field. - * name: The name to give to the cpuset directory. Will be copied. - * mode: mode to set on new directory. - */ - -static int cpuset_create_dir(struct cpuset *cs, const char *name, int mode) -{ - struct dentry *dentry = NULL; - struct dentry *parent; - int error = 0; - - parent = cs->parent->dentry; - dentry = cpuset_get_dentry(parent, name); - if (IS_ERR(dentry)) - return PTR_ERR(dentry); - error = cpuset_create_file(dentry, S_IFDIR | mode); - if (!error) { - dentry->d_fsdata = cs; - inc_nlink(parent->d_inode); - cs->dentry = dentry; - } - dput(dentry); - - return error; -} - -static int cpuset_add_file(struct dentry *dir, const struct cftype *cft) -{ - struct dentry *dentry; - int error; - - mutex_lock(&dir->d_inode->i_mutex); - dentry = cpuset_get_dentry(dir, cft->name); - if (!IS_ERR(dentry)) { - error = cpuset_create_file(dentry, 0644 | S_IFREG); - if (!error) - dentry->d_fsdata = (void *)cft; - dput(dentry); - } else - error = PTR_ERR(dentry); - mutex_unlock(&dir->d_inode->i_mutex); - return error; -} - -/* - * Stuff for reading the 'tasks' file. - * - * Reading this file can return large amounts of data if a cpuset has - * *lots* of attached tasks. So it may need several calls to read(), - * but we cannot guarantee that the information we produce is correct - * unless we produce it entirely atomically. - * - * Upon tasks file open(), a struct ctr_struct is allocated, that - * will have a pointer to an array (also allocated here). The struct - * ctr_struct * is stored in file->private_data. Its resources will - * be freed by release() when the file is closed. The array is used - * to sprintf the PIDs and then used by read(). - */ - -/* cpusets_tasks_read array */ - -struct ctr_struct { - char *buf; - int bufsz; -}; - -/* - * Load into 'pidarray' up to 'npids' of the tasks using cpuset 'cs'. - * Return actual number of pids loaded. No need to task_lock(p) - * when reading out p->cpuset, as we don't really care if it changes - * on the next cycle, and we are not going to try to dereference it. - */ -static int pid_array_load(pid_t *pidarray, int npids, struct cpuset *cs) -{ - int n = 0; - struct task_struct *g, *p; - - read_lock(&tasklist_lock); - - do_each_thread(g, p) { - if (p->cpuset == cs) { - pidarray[n++] = p->pid; - if (unlikely(n == npids)) - goto array_full; - } - } while_each_thread(g, p); - -array_full: - read_unlock(&tasklist_lock); - return n; -} - -static int cmppid(const void *a, const void *b) -{ - return *(pid_t *)a - *(pid_t *)b; -} - -/* - * Convert array 'a' of 'npids' pid_t's to a string of newline separated - * decimal pids in 'buf'. Don't write more than 'sz' chars, but return - * count 'cnt' of how many chars would be written if buf were large enough. - */ -static int pid_array_to_buf(char *buf, int sz, pid_t *a, int npids) -{ - int cnt = 0; - int i; - - for (i = 0; i < npids; i++) - cnt += snprintf(buf + cnt, max(sz - cnt, 0), "%d\n", a[i]); - return cnt; -} - -/* - * Handle an open on 'tasks' file. Prepare a buffer listing the - * process id's of tasks currently attached to the cpuset being opened. - * - * Does not require any specific cpuset mutexes, and does not take any. - */ -static int cpuset_tasks_open(struct inode *unused, struct file *file) -{ - struct cpuset *cs = __d_cs(file->f_dentry->d_parent); - struct ctr_struct *ctr; - pid_t *pidarray; - int npids; - char c; - - if (!(file->f_mode & FMODE_READ)) - return 0; - - ctr = kmalloc(sizeof(*ctr), GFP_KERNEL); - if (!ctr) - goto err0; - - /* - * If cpuset gets more users after we read count, we won't have - * enough space - tough. This race is indistinguishable to the - * caller from the case that the additional cpuset users didn't - * show up until sometime later on. - */ - npids = atomic_read(&cs->count); - pidarray = kmalloc(npids * sizeof(pid_t), GFP_KERNEL); - if (!pidarray) - goto err1; - - npids = pid_array_load(pidarray, npids, cs); - sort(pidarray, npids, sizeof(pid_t), cmppid, NULL); - - /* Call pid_array_to_buf() twice, first just to get bufsz */ - ctr->bufsz = pid_array_to_buf(&c, sizeof(c), pidarray, npids) + 1; - ctr->buf = kmalloc(ctr->bufsz, GFP_KERNEL); - if (!ctr->buf) - goto err2; - ctr->bufsz = pid_array_to_buf(ctr->buf, ctr->bufsz, pidarray, npids); - - kfree(pidarray); - file->private_data = ctr; - return 0; - -err2: - kfree(pidarray); -err1: - kfree(ctr); -err0: - return -ENOMEM; -} - -static ssize_t cpuset_tasks_read(struct file *file, char __user *buf, - size_t nbytes, loff_t *ppos) -{ - struct ctr_struct *ctr = file->private_data; - - if (*ppos + nbytes > ctr->bufsz) - nbytes = ctr->bufsz - *ppos; - if (copy_to_user(buf, ctr->buf + *ppos, nbytes)) - return -EFAULT; - *ppos += nbytes; - return nbytes; -} - -static int cpuset_tasks_release(struct inode *unused_inode, struct file *file) -{ - struct ctr_struct *ctr; - - if (file->f_mode & FMODE_READ) { - ctr = file->private_data; - kfree(ctr->buf); - kfree(ctr); - } - return 0; -} /* * for the common functions, 'private' gives the type of file */ -static struct cftype cft_tasks = { - .name = "tasks", - .open = cpuset_tasks_open, - .read = cpuset_tasks_read, - .release = cpuset_tasks_release, - .private = FILE_TASKLIST, -}; - static struct cftype cft_cpus = { .name = "cpus", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_CPULIST, }; static struct cftype cft_mems = { .name = "mems", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_MEMLIST, }; static struct cftype cft_cpu_exclusive = { .name = "cpu_exclusive", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_CPU_EXCLUSIVE, }; static struct cftype cft_mem_exclusive = { .name = "mem_exclusive", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_MEM_EXCLUSIVE, }; -static struct cftype cft_notify_on_release = { - .name = "notify_on_release", - .private = FILE_NOTIFY_ON_RELEASE, -}; - static struct cftype cft_memory_migrate = { .name = "memory_migrate", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_MEMORY_MIGRATE, }; static struct cftype cft_memory_pressure_enabled = { .name = "memory_pressure_enabled", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_MEMORY_PRESSURE_ENABLED, }; static struct cftype cft_memory_pressure = { .name = "memory_pressure", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_MEMORY_PRESSURE, }; static struct cftype cft_spread_page = { .name = "memory_spread_page", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_SPREAD_PAGE, }; static struct cftype cft_spread_slab = { .name = "memory_spread_slab", + .read = cpuset_common_file_read, + .write = cpuset_common_file_write, .private = FILE_SPREAD_SLAB, }; -static int cpuset_populate_dir(struct dentry *cs_dentry) +int cpuset_populate_dir(struct container *cont) { int err; - if ((err = cpuset_add_file(cs_dentry, &cft_cpus)) < 0) + if ((err = container_add_file(cont, &cft_cpus)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_mems)) < 0) + if ((err = container_add_file(cont, &cft_mems)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_cpu_exclusive)) < 0) + if ((err = container_add_file(cont, &cft_cpu_exclusive)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_mem_exclusive)) < 0) + if ((err = container_add_file(cont, &cft_mem_exclusive)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_notify_on_release)) < 0) + if ((err = container_add_file(cont, &cft_memory_migrate)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_memory_migrate)) < 0) + if ((err = container_add_file(cont, &cft_memory_pressure)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_memory_pressure)) < 0) + if ((err = container_add_file(cont, &cft_spread_page)) < 0) return err; - if ((err = cpuset_add_file(cs_dentry, &cft_spread_page)) < 0) - return err; - if ((err = cpuset_add_file(cs_dentry, &cft_spread_slab)) < 0) - return err; - if ((err = cpuset_add_file(cs_dentry, &cft_tasks)) < 0) + if ((err = container_add_file(cont, &cft_spread_slab)) < 0) return err; + /* memory_pressure_enabled is in root cpuset only */ + if (err == 0 && !cont->parent) + err = container_add_file(cont, &cft_memory_pressure_enabled); return 0; } @@ -1869,66 +1119,31 @@ static int cpuset_populate_dir(struct de * Must be called with the mutex on the parent inode held */ -static long cpuset_create(struct cpuset *parent, const char *name, int mode) +int cpuset_create(struct container *cont) { struct cpuset *cs; - int err; + struct cpuset *parent = cont->parent->cpuset; cs = kmalloc(sizeof(*cs), GFP_KERNEL); if (!cs) return -ENOMEM; - mutex_lock(&manage_mutex); cpuset_update_task_memory_state(); cs->flags = 0; - if (notify_on_release(parent)) - set_bit(CS_NOTIFY_ON_RELEASE, &cs->flags); if (is_spread_page(parent)) set_bit(CS_SPREAD_PAGE, &cs->flags); if (is_spread_slab(parent)) set_bit(CS_SPREAD_SLAB, &cs->flags); cs->cpus_allowed = CPU_MASK_NONE; cs->mems_allowed = NODE_MASK_NONE; - atomic_set(&cs->count, 0); - INIT_LIST_HEAD(&cs->sibling); - INIT_LIST_HEAD(&cs->children); cs->mems_generation = cpuset_mems_generation++; fmeter_init(&cs->fmeter); cs->parent = parent; - - mutex_lock(&callback_mutex); - list_add(&cs->sibling, &cs->parent->children); + cont->cpuset = cs; + cs->container = cont; number_of_cpusets++; - mutex_unlock(&callback_mutex); - - err = cpuset_create_dir(cs, name, mode); - if (err < 0) - goto err; - - /* - * Release manage_mutex before cpuset_populate_dir() because it - * will down() this new directory's i_mutex and if we race with - * another mkdir, we might deadlock. - */ - mutex_unlock(&manage_mutex); - - err = cpuset_populate_dir(cs->dentry); - /* If err < 0, we have a half-filled directory - oh well ;) */ return 0; -err: - list_del(&cs->sibling); - mutex_unlock(&manage_mutex); - kfree(cs); - return err; -} - -static int cpuset_mkdir(struct inode *dir, struct dentry *dentry, int mode) -{ - struct cpuset *c_parent = dentry->d_parent->d_fsdata; - - /* the vfs holds inode->i_mutex already */ - return cpuset_create(c_parent, dentry->d_name.name, mode | S_IFDIR); } /* @@ -1942,49 +1157,16 @@ static int cpuset_mkdir(struct inode *di * nesting would risk an ABBA deadlock. */ -static int cpuset_rmdir(struct inode *unused_dir, struct dentry *dentry) +void cpuset_destroy(struct container *cont) { - struct cpuset *cs = dentry->d_fsdata; - struct dentry *d; - struct cpuset *parent; - char *pathbuf = NULL; - - /* the vfs holds both inode->i_mutex already */ + struct cpuset *cs = cont->cpuset; - mutex_lock(&manage_mutex); cpuset_update_task_memory_state(); - if (atomic_read(&cs->count) > 0) { - mutex_unlock(&manage_mutex); - return -EBUSY; - } - if (!list_empty(&cs->children)) { - mutex_unlock(&manage_mutex); - return -EBUSY; - } if (is_cpu_exclusive(cs)) { int retval = update_flag(CS_CPU_EXCLUSIVE, cs, "0"); - if (retval < 0) { - mutex_unlock(&manage_mutex); - return retval; - } + BUG_ON(retval); } - parent = cs->parent; - mutex_lock(&callback_mutex); - set_bit(CS_REMOVED, &cs->flags); - list_del(&cs->sibling); /* delete my sibling from parent->children */ - spin_lock(&cs->dentry->d_lock); - d = dget(cs->dentry); - cs->dentry = NULL; - spin_unlock(&d->d_lock); - cpuset_d_remove_dir(d); - dput(d); number_of_cpusets--; - mutex_unlock(&callback_mutex); - if (list_empty(&parent->children)) - check_for_release(parent, &pathbuf); - mutex_unlock(&manage_mutex); - cpuset_release_agent(pathbuf); - return 0; } /* @@ -1995,10 +1177,10 @@ static int cpuset_rmdir(struct inode *un int __init cpuset_init_early(void) { - struct task_struct *tsk = current; - - tsk->cpuset = &top_cpuset; - tsk->cpuset->mems_generation = cpuset_mems_generation++; + struct container *cont = current->container; + cont->cpuset = &top_cpuset; + top_cpuset.container = cont; + cont->cpuset->mems_generation = cpuset_mems_generation++; return 0; } @@ -2010,39 +1192,21 @@ int __init cpuset_init_early(void) int __init cpuset_init(void) { - struct dentry *root; - int err; - + int err = 0; top_cpuset.cpus_allowed = CPU_MASK_ALL; top_cpuset.mems_allowed = NODE_MASK_ALL; fmeter_init(&top_cpuset.fmeter); top_cpuset.mems_generation = cpuset_mems_generation++; - init_task.cpuset = &top_cpuset; - +#ifdef CONFIG_CPUSETS_LEGACY_API err = register_filesystem(&cpuset_fs_type); if (err < 0) - goto out; - cpuset_mount = kern_mount(&cpuset_fs_type); - if (IS_ERR(cpuset_mount)) { - printk(KERN_ERR "cpuset: could not mount!\n"); - err = PTR_ERR(cpuset_mount); - cpuset_mount = NULL; - goto out; - } - root = cpuset_mount->mnt_sb->s_root; - root->d_fsdata = &top_cpuset; - inc_nlink(root->d_inode); - top_cpuset.dentry = root; - root->d_inode->i_op = &cpuset_dir_inode_operations; + return err; +#endif + number_of_cpusets = 1; - err = cpuset_populate_dir(root); - /* memory_pressure_enabled is in root cpuset only */ - if (err == 0) - err = cpuset_add_file(root, &cft_memory_pressure_enabled); -out: - return err; + return 0; } #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_MEMORY_HOTPLUG) @@ -2099,15 +1263,15 @@ static void guarantee_online_cpus_mems_i static void common_cpu_mem_hotplug_unplug(void) { - mutex_lock(&manage_mutex); - mutex_lock(&callback_mutex); + container_manage_lock(); + container_lock(); guarantee_online_cpus_mems_in_subtree(&top_cpuset); top_cpuset.cpus_allowed = cpu_online_map; top_cpuset.mems_allowed = node_online_map; - mutex_unlock(&callback_mutex); - mutex_unlock(&manage_mutex); + container_unlock(); + container_manage_unlock(); } #endif @@ -2158,111 +1322,6 @@ void __init cpuset_init_smp(void) } /** - * cpuset_fork - attach newly forked task to its parents cpuset. - * @tsk: pointer to task_struct of forking parent process. - * - * Description: A task inherits its parent's cpuset at fork(). - * - * A pointer to the shared cpuset was automatically copied in fork.c - * by dup_task_struct(). However, we ignore that copy, since it was - * not made under the protection of task_lock(), so might no longer be - * a valid cpuset pointer. attach_task() might have already changed - * current->cpuset, allowing the previously referenced cpuset to - * be removed and freed. Instead, we task_lock(current) and copy - * its present value of current->cpuset for our freshly forked child. - * - * At the point that cpuset_fork() is called, 'current' is the parent - * task, and the passed argument 'child' points to the child task. - **/ - -void cpuset_fork(struct task_struct *child) -{ - task_lock(current); - child->cpuset = current->cpuset; - atomic_inc(&child->cpuset->count); - task_unlock(current); -} - -/** - * cpuset_exit - detach cpuset from exiting task - * @tsk: pointer to task_struct of exiting process - * - * Description: Detach cpuset from @tsk and release it. - * - * Note that cpusets marked notify_on_release force every task in - * them to take the global manage_mutex mutex when exiting. - * This could impact scaling on very large systems. Be reluctant to - * use notify_on_release cpusets where very high task exit scaling - * is required on large systems. - * - * Don't even think about derefencing 'cs' after the cpuset use count - * goes to zero, except inside a critical section guarded by manage_mutex - * or callback_mutex. Otherwise a zero cpuset use count is a license to - * any other task to nuke the cpuset immediately, via cpuset_rmdir(). - * - * This routine has to take manage_mutex, not callback_mutex, because - * it is holding that mutex while calling check_for_release(), - * which calls kmalloc(), so can't be called holding callback_mutex(). - * - * We don't need to task_lock() this reference to tsk->cpuset, - * because tsk is already marked PF_EXITING, so attach_task() won't - * mess with it, or task is a failed fork, never visible to attach_task. - * - * the_top_cpuset_hack: - * - * Set the exiting tasks cpuset to the root cpuset (top_cpuset). - * - * Don't leave a task unable to allocate memory, as that is an - * accident waiting to happen should someone add a callout in - * do_exit() after the cpuset_exit() call that might allocate. - * If a task tries to allocate memory with an invalid cpuset, - * it will oops in cpuset_update_task_memory_state(). - * - * We call cpuset_exit() while the task is still competent to - * handle notify_on_release(), then leave the task attached to - * the root cpuset (top_cpuset) for the remainder of its exit. - * - * To do this properly, we would increment the reference count on - * top_cpuset, and near the very end of the kernel/exit.c do_exit() - * code we would add a second cpuset function call, to drop that - * reference. This would just create an unnecessary hot spot on - * the top_cpuset reference count, to no avail. - * - * Normally, holding a reference to a cpuset without bumping its - * count is unsafe. The cpuset could go away, or someone could - * attach us to a different cpuset, decrementing the count on - * the first cpuset that we never incremented. But in this case, - * top_cpuset isn't going away, and either task has PF_EXITING set, - * which wards off any attach_task() attempts, or task is a failed - * fork, never visible to attach_task. - * - * Another way to do this would be to set the cpuset pointer - * to NULL here, and check in cpuset_update_task_memory_state() - * for a NULL pointer. This hack avoids that NULL check, for no - * cost (other than this way too long comment ;). - **/ - -void cpuset_exit(struct task_struct *tsk) -{ - struct cpuset *cs; - - cs = tsk->cpuset; - tsk->cpuset = &top_cpuset; /* the_top_cpuset_hack - see above */ - - if (notify_on_release(cs)) { - char *pathbuf = NULL; - - mutex_lock(&manage_mutex); - if (atomic_dec_and_test(&cs->count)) - check_for_release(cs, &pathbuf); - mutex_unlock(&manage_mutex); - cpuset_release_agent(pathbuf); - } else { - atomic_dec(&cs->count); - } -} - -/** * cpuset_cpus_allowed - return cpus_allowed mask from a tasks cpuset. * @tsk: pointer to task_struct from which to obtain cpuset->cpus_allowed. * @@ -2276,11 +1335,11 @@ cpumask_t cpuset_cpus_allowed(struct tas { cpumask_t mask; - mutex_lock(&callback_mutex); + container_lock(); task_lock(tsk); - guarantee_online_cpus(tsk->cpuset, &mask); + guarantee_online_cpus(tsk->container->cpuset, &mask); task_unlock(tsk); - mutex_unlock(&callback_mutex); + container_unlock(); return mask; } @@ -2304,11 +1363,11 @@ nodemask_t cpuset_mems_allowed(struct ta { nodemask_t mask; - mutex_lock(&callback_mutex); + container_lock(); task_lock(tsk); - guarantee_online_mems(tsk->cpuset, &mask); + guarantee_online_mems(tsk->container->cpuset, &mask); task_unlock(tsk); - mutex_unlock(&callback_mutex); + container_unlock(); return mask; } @@ -2408,45 +1467,18 @@ int __cpuset_zone_allowed(struct zone *z return 1; /* Not hardwall and node outside mems_allowed: scan up cpusets */ - mutex_lock(&callback_mutex); + container_lock(); task_lock(current); - cs = nearest_exclusive_ancestor(current->cpuset); + cs = nearest_exclusive_ancestor(current->container->cpuset); task_unlock(current); allowed = node_isset(node, cs->mems_allowed); - mutex_unlock(&callback_mutex); + container_unlock(); return allowed; } /** - * cpuset_lock - lock out any changes to cpuset structures - * - * The out of memory (oom) code needs to mutex_lock cpusets - * from being changed while it scans the tasklist looking for a - * task in an overlapping cpuset. Expose callback_mutex via this - * cpuset_lock() routine, so the oom code can lock it, before - * locking the task list. The tasklist_lock is a spinlock, so - * must be taken inside callback_mutex. - */ - -void cpuset_lock(void) -{ - mutex_lock(&callback_mutex); -} - -/** - * cpuset_unlock - release lock on cpuset changes - * - * Undo the lock taken in a previous cpuset_lock() call. - */ - -void cpuset_unlock(void) -{ - mutex_unlock(&callback_mutex); -} - -/** * cpuset_mem_spread_node() - On which node to begin search for a page * * If a task is marked PF_SPREAD_PAGE or PF_SPREAD_SLAB (as for @@ -2506,7 +1538,7 @@ int cpuset_excl_nodes_overlap(const stru task_unlock(current); goto done; } - cs1 = nearest_exclusive_ancestor(current->cpuset); + cs1 = nearest_exclusive_ancestor(current->container->cpuset); task_unlock(current); task_lock((struct task_struct *)p); @@ -2514,7 +1546,7 @@ int cpuset_excl_nodes_overlap(const stru task_unlock((struct task_struct *)p); goto done; } - cs2 = nearest_exclusive_ancestor(p->cpuset); + cs2 = nearest_exclusive_ancestor(p->container->cpuset); task_unlock((struct task_struct *)p); overlap = nodes_intersects(cs1->mems_allowed, cs2->mems_allowed); @@ -2553,70 +1585,11 @@ void __cpuset_memory_pressure_bump(void) struct cpuset *cs; task_lock(current); - cs = current->cpuset; + cs = current->container->cpuset; fmeter_markevent(&cs->fmeter); task_unlock(current); } -/* - * proc_cpuset_show() - * - Print tasks cpuset path into seq_file. - * - Used for /proc//cpuset. - * - No need to task_lock(tsk) on this tsk->cpuset reference, as it - * doesn't really matter if tsk->cpuset changes after we read it, - * and we take manage_mutex, keeping attach_task() from changing it - * anyway. No need to check that tsk->cpuset != NULL, thanks to - * the_top_cpuset_hack in cpuset_exit(), which sets an exiting tasks - * cpuset to top_cpuset. - */ -static int proc_cpuset_show(struct seq_file *m, void *v) -{ - struct pid *pid; - struct task_struct *tsk; - char *buf; - int retval; - - retval = -ENOMEM; - buf = kmalloc(PAGE_SIZE, GFP_KERNEL); - if (!buf) - goto out; - - retval = -ESRCH; - pid = m->private; - tsk = get_pid_task(pid, PIDTYPE_PID); - if (!tsk) - goto out_free; - - retval = -EINVAL; - mutex_lock(&manage_mutex); - - retval = cpuset_path(tsk->cpuset, buf, PAGE_SIZE); - if (retval < 0) - goto out_unlock; - seq_puts(m, buf); - seq_putc(m, '\n'); -out_unlock: - mutex_unlock(&manage_mutex); - put_task_struct(tsk); -out_free: - kfree(buf); -out: - return retval; -} - -static int cpuset_open(struct inode *inode, struct file *file) -{ - struct pid *pid = PROC_I(inode)->pid; - return single_open(file, proc_cpuset_show, pid); -} - -struct file_operations proc_cpuset_operations = { - .open = cpuset_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; - /* Display task cpus_allowed, mems_allowed in /proc//status file. */ char *cpuset_task_status_allowed(struct task_struct *task, char *buffer) { Index: container-2.6.19-rc2/init/Kconfig =================================================================== --- container-2.6.19-rc2.orig/init/Kconfig +++ container-2.6.19-rc2/init/Kconfig @@ -238,17 +238,12 @@ config IKCONFIG_PROC through /proc/config.gz. config CONTAINERS - bool "Container support" - help - This option will let you create and manage process containers, - which can be used to aggregate multiple processes, e.g. for - the purposes of resource tracking. - - Say N if unsure + bool config CPUSETS bool "Cpuset support" depends on SMP + select CONTAINERS help This option will let you create and manage CPUSETs which allow dynamically partitioning a system into sets of CPUs and @@ -257,6 +252,16 @@ config CPUSETS Say N if unsure. +config CPUSETS_LEGACY_API + bool "Maintain the existing cpuset API for generic container features" + depends on CPUSETS + default n + help + This option preserves the following legacy CPUset behaviour: + - /proc//cpuset + - defaults cpuset subsystem to enabled + - defaults container release agent to /sbin/cpuset_release_agent + config RELAY bool "Kernel->user space relay support (formerly relayfs)" help Index: container-2.6.19-rc2/mm/oom_kill.c =================================================================== --- container-2.6.19-rc2.orig/mm/oom_kill.c +++ container-2.6.19-rc2/mm/oom_kill.c @@ -394,7 +394,7 @@ void out_of_memory(struct zonelist *zone show_mem(); } - cpuset_lock(); + container_lock(); read_lock(&tasklist_lock); /* @@ -428,7 +428,7 @@ retry: /* Found nothing?!?! Either we hang forever, or we panic. */ if (!p) { read_unlock(&tasklist_lock); - cpuset_unlock(); + container_unlock(); panic("Out of memory and no killable processes...\n"); } @@ -440,7 +440,7 @@ retry: out: read_unlock(&tasklist_lock); - cpuset_unlock(); + container_unlock(); /* * Give "p" a good chance of killing itself before we Index: container-2.6.19-rc2/include/linux/sched.h =================================================================== --- container-2.6.19-rc2.orig/include/linux/sched.h +++ container-2.6.19-rc2/include/linux/sched.h @@ -721,7 +721,6 @@ extern unsigned int max_cache_size; struct io_context; /* See blkdev.h */ struct container; -struct cpuset; #define NGROUPS_SMALL 32 #define NGROUPS_PER_BLOCK ((int)(PAGE_SIZE / sizeof(gid_t))) struct group_info { @@ -1002,7 +1001,6 @@ struct task_struct { short il_next; #endif #ifdef CONFIG_CPUSETS - struct cpuset *cpuset; nodemask_t mems_allowed; int cpuset_mems_generation; int cpuset_mem_spread_rotor; @@ -1433,7 +1431,7 @@ static inline int thread_group_empty(str /* * Protects ->fs, ->files, ->mm, ->group_info, ->comm, keyring * subscriptions and synchronises with wait4(). Also used in procfs. Also - * pins the final release of task.io_context. Also protects ->cpuset. + * pins the final release of task.io_context. Also protects ->container. * * Nests both inside and outside of read_lock(&tasklist_lock). * It must not be nested with write_lock_irq(&tasklist_lock), Index: container-2.6.19-rc2/Documentation/cpusets.txt =================================================================== --- container-2.6.19-rc2.orig/Documentation/cpusets.txt +++ container-2.6.19-rc2/Documentation/cpusets.txt @@ -7,6 +7,7 @@ Written by Simon.Derr@bull.net Portions Copyright (c) 2004-2006 Silicon Graphics, Inc. Modified by Paul Jackson Modified by Christoph Lameter +Modified by Paul Menage CONTENTS: ========= @@ -16,10 +17,9 @@ CONTENTS: 1.2 Why are cpusets needed ? 1.3 How are cpusets implemented ? 1.4 What are exclusive cpusets ? - 1.5 What does notify_on_release do ? - 1.6 What is memory_pressure ? - 1.7 What is memory spread ? - 1.8 How do I use cpusets ? + 1.5 What is memory_pressure ? + 1.6 What is memory spread ? + 1.7 How do I use cpusets ? 2. Usage Examples and Syntax 2.1 Basic Usage 2.2 Adding/removing cpus @@ -43,18 +43,19 @@ hierarchy visible in a virtual file syst hooks, beyond what is already present, required to manage dynamic job placement on large systems. -Each task has a pointer to a cpuset. Multiple tasks may reference -the same cpuset. Requests by a task, using the sched_setaffinity(2) -system call to include CPUs in its CPU affinity mask, and using the -mbind(2) and set_mempolicy(2) system calls to include Memory Nodes -in its memory policy, are both filtered through that tasks cpuset, -filtering out any CPUs or Memory Nodes not in that cpuset. The -scheduler will not schedule a task on a CPU that is not allowed in -its cpus_allowed vector, and the kernel page allocator will not -allocate a page on a node that is not allowed in the requesting tasks -mems_allowed vector. +Cpusets use the generic container subsystem described in +Documentation/container.txt. -User level code may create and destroy cpusets by name in the cpuset +Requests by a task, using the sched_setaffinity(2) system call to +include CPUs in its CPU affinity mask, and using the mbind(2) and +set_mempolicy(2) system calls to include Memory Nodes in its memory +policy, are both filtered through that tasks cpuset, filtering out any +CPUs or Memory Nodes not in that cpuset. The scheduler will not +schedule a task on a CPU that is not allowed in its cpus_allowed +vector, and the kernel page allocator will not allocate a page on a +node that is not allowed in the requesting tasks mems_allowed vector. + +User level code may create and destroy cpusets by name in the container virtual file system, manage the attributes and permissions of these cpusets and which CPUs and Memory Nodes are assigned to each cpuset, specify and query to which cpuset a task is assigned, and list the @@ -117,7 +118,7 @@ Cpusets extends these two mechanisms as - Cpusets are sets of allowed CPUs and Memory Nodes, known to the kernel. - Each task in the system is attached to a cpuset, via a pointer - in the task structure to a reference counted cpuset structure. + in the task structure to a reference counted container structure. - Calls to sched_setaffinity are filtered to just those CPUs allowed in that tasks cpuset. - Calls to mbind and set_mempolicy are filtered to just @@ -152,15 +153,10 @@ into the rest of the kernel, none in per - in page_alloc.c, to restrict memory to allowed nodes. - in vmscan.c, to restrict page recovery to the current cpuset. -In addition a new file system, of type "cpuset" may be mounted, -typically at /dev/cpuset, to enable browsing and modifying the cpusets -presently known to the kernel. No new system calls are added for -cpusets - all support for querying and modifying cpusets is via -this cpuset file system. - -Each task under /proc has an added file named 'cpuset', displaying -the cpuset name, as the path relative to the root of the cpuset file -system. +You should mount the "container" filesystem type in order to enable +browsing and modifying the cpusets presently known to the kernel. No +new system calls are added for cpusets - all support for querying and +modifying cpusets is via this cpuset file system. The /proc//status file for each task has two added lines, displaying the tasks cpus_allowed (on which CPUs it may be scheduled) @@ -170,16 +166,15 @@ in the format seen in the following exam Cpus_allowed: ffffffff,ffffffff,ffffffff,ffffffff Mems_allowed: ffffffff,ffffffff -Each cpuset is represented by a directory in the cpuset file system -containing the following files describing that cpuset: +Each cpuset is represented by a directory in the container file system +containing (on top of the standard container files) the following +files describing that cpuset: - cpus: list of CPUs in that cpuset - mems: list of Memory Nodes in that cpuset - memory_migrate flag: if set, move pages to cpusets nodes - cpu_exclusive flag: is cpu placement exclusive? - mem_exclusive flag: is memory placement exclusive? - - tasks: list of tasks (by pid) attached to that cpuset - - notify_on_release flag: run /sbin/cpuset_release_agent on exit? - memory_pressure: measure of how much paging pressure in cpuset In addition, the root cpuset only has the following file: @@ -253,21 +248,7 @@ such as requests from interrupt handlers outside even a mem_exclusive cpuset. -1.5 What does notify_on_release do ? ------------------------------------- - -If the notify_on_release flag is enabled (1) in a cpuset, then whenever -the last task in the cpuset leaves (exits or attaches to some other -cpuset) and the last child cpuset of that cpuset is removed, then -the kernel runs the command /sbin/cpuset_release_agent, supplying the -pathname (relative to the mount point of the cpuset file system) of the -abandoned cpuset. This enables automatic removal of abandoned cpusets. -The default value of notify_on_release in the root cpuset at system -boot is disabled (0). The default value of other cpusets at creation -is the current value of their parents notify_on_release setting. - - -1.6 What is memory_pressure ? +1.5 What is memory_pressure ? ----------------------------- The memory_pressure of a cpuset provides a simple per-cpuset metric of the rate that the tasks in a cpuset are attempting to free up in @@ -324,7 +305,7 @@ the tasks in the cpuset, in units of rec times 1000. -1.7 What is memory spread ? +1.6 What is memory spread ? --------------------------- There are two boolean flag files per cpuset that control where the kernel allocates pages for the file system buffers and related in @@ -395,7 +376,7 @@ data set, the memory allocation across t can become very uneven. -1.8 How do I use cpusets ? +1.7 How do I use cpusets ? -------------------------- In order to minimize the impact of cpusets on critical kernel @@ -485,7 +466,7 @@ than stress the kernel. To start a new job that is to be contained within a cpuset, the steps are: 1) mkdir /dev/cpuset - 2) mount -t cpuset none /dev/cpuset + 2) mount -t container none /dev/cpuset 3) Create the new cpuset by doing mkdir's and write's (or echo's) in the /dev/cpuset virtual file system. 4) Start a task that will be the "founding father" of the new job. @@ -497,7 +478,7 @@ For example, the following sequence of c named "Charlie", containing just CPUs 2 and 3, and Memory Node 1, and then start a subshell 'sh' in that cpuset: - mount -t cpuset none /dev/cpuset + mount -t container none /dev/cpuset cd /dev/cpuset mkdir Charlie cd Charlie @@ -507,7 +488,7 @@ and then start a subshell 'sh' in that c sh # The subshell 'sh' is now running in cpuset Charlie # The next line should display '/Charlie' - cat /proc/self/cpuset + cat /proc/self/container In the future, a C library interface to cpusets will likely be available. For now, the only way to query or modify cpusets is @@ -529,7 +510,7 @@ Creating, modifying, using the cpusets c virtual filesystem. To mount it, type: -# mount -t cpuset none /dev/cpuset +# mount -t container none /dev/cpuset Then under /dev/cpuset you can find a tree that corresponds to the tree of the cpusets in the system. For instance, /dev/cpuset Index: container-2.6.19-rc2/fs/super.c =================================================================== --- container-2.6.19-rc2.orig/fs/super.c +++ container-2.6.19-rc2/fs/super.c @@ -39,11 +39,6 @@ #include #include - -void get_filesystem(struct file_system_type *fs); -void put_filesystem(struct file_system_type *fs); -struct file_system_type *get_fs_type(const char *name); - LIST_HEAD(super_blocks); DEFINE_SPINLOCK(sb_lock); Index: container-2.6.19-rc2/include/linux/fs.h =================================================================== --- container-2.6.19-rc2.orig/include/linux/fs.h +++ container-2.6.19-rc2/include/linux/fs.h @@ -1864,6 +1864,8 @@ extern int vfs_fstat(unsigned int, struc extern int vfs_ioctl(struct file *, unsigned int, unsigned int, unsigned long); +extern void get_filesystem(struct file_system_type *fs); +extern void put_filesystem(struct file_system_type *fs); extern struct file_system_type *get_fs_type(const char *name); extern struct super_block *get_super(struct block_device *); extern struct super_block *user_get_super(dev_t); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/