| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1212791250-32320-3-git-send-email-righi.andrea@gmail.com>
Date: Sat, 7 Jun 2008 00:27:29 +0200
From: Andrea Righi <righi.andrea@...il.com>
To: balbir@...ux.vnet.ibm.com, menage@...gle.com
Cc: matt@...ehost.com, roberto@...it.it, randy.dunlap@...cle.com,
akpm@...ux-foundation.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/3] i/o bandwidth controller infrastructure
This is the core io-throttle kernel infrastructure. It creates the basic
interfaces to cgroups and implements the I/O measurement and throttling
functions.
Signed-off-by: Andrea Righi <righi.andrea@...il.com>
---
block/Makefile | 2 +
block/blk-io-throttle.c | 405 +++++++++++++++++++++++++++++++++++++++
include/linux/blk-io-throttle.h | 12 ++
include/linux/cgroup_subsys.h | 6 +
init/Kconfig | 10 +
5 files changed, 435 insertions(+), 0 deletions(-)
create mode 100644 block/blk-io-throttle.c
create mode 100644 include/linux/blk-io-throttle.h
diff --git a/block/Makefile b/block/Makefile
index 5a43c7d..8dec69b 100644
--- a/block/Makefile
+++ b/block/Makefile
@@ -14,3 +14,5 @@ obj-$(CONFIG_IOSCHED_CFQ) += cfq-iosched.o
obj-$(CONFIG_BLK_DEV_IO_TRACE) += blktrace.o
obj-$(CONFIG_BLOCK_COMPAT) += compat_ioctl.o
+
+obj-$(CONFIG_CGROUP_IO_THROTTLE) += blk-io-throttle.o
diff --git a/block/blk-io-throttle.c b/block/blk-io-throttle.c
new file mode 100644
index 0000000..804df88
--- /dev/null
+++ b/block/blk-io-throttle.c
@@ -0,0 +1,405 @@
+/*
+ * blk-io-throttle.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * Copyright (C) 2008 Andrea Righi <righi.andrea@...il.com>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/cgroup.h>
+#include <linux/slab.h>
+#include <linux/gfp.h>
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/fs.h>
+#include <linux/jiffies.h>
+#include <linux/hardirq.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+#include <linux/blk-io-throttle.h>
+
+#define iothrottle_for_each(n, r) \
+ for (n = rb_first(r); n; n = rb_next(n))
+
+struct iothrottle_node {
+ struct rb_node node;
+ dev_t dev;
+ unsigned long iorate;
+ unsigned long req;
+ unsigned long last_request;
+};
+
+struct iothrottle {
+ struct cgroup_subsys_state css;
+ spinlock_t lock; /* protects the accounting of the cgroup i/o stats */
+ struct rb_root tree;
+};
+
+static inline struct iothrottle *cgroup_to_iothrottle(struct cgroup *cont)
+{
+ return container_of(cgroup_subsys_state(cont, iothrottle_subsys_id),
+ struct iothrottle, css);
+}
+
+static inline struct iothrottle *task_to_iothrottle(struct task_struct *task)
+{
+ return container_of(task_subsys_state(task, iothrottle_subsys_id),
+ struct iothrottle, css);
+}
+
+static inline struct iothrottle_node *iothrottle_search_node(
+ const struct iothrottle *iot,
+ dev_t dev)
+{
+ struct rb_node *node = (&iot->tree)->rb_node;
+
+ while (node) {
+ struct iothrottle_node *data = container_of(node,
+ struct iothrottle_node, node);
+ if (dev < data->dev)
+ node = node->rb_left;
+ else if (dev > data->dev)
+ node = node->rb_right;
+ else
+ return data;
+ }
+ return NULL;
+}
+
+static inline int iothrottle_insert_node(struct iothrottle *iot,
+ struct iothrottle_node *data)
+{
+ struct rb_root *root = &iot->tree;
+ struct rb_node **new = &(root->rb_node), *parent = NULL;
+
+ while (*new) {
+ struct iothrottle_node *this = container_of(*new,
+ struct iothrottle_node, node);
+ parent = *new;
+ if (data->dev < this->dev)
+ new = &((*new)->rb_left);
+ else if (data->dev > this->dev)
+ new = &((*new)->rb_right);
+ else
+ return -EINVAL;
+ }
+ rb_link_node(&data->node, parent, new);
+ rb_insert_color(&data->node, root);
+
+ return 0;
+}
+
+static inline void iothrottle_delete_node(struct iothrottle *iot, dev_t dev)
+{
+ struct iothrottle_node *data = iothrottle_search_node(iot, dev);
+
+ if (likely(data)) {
+ rb_erase(&data->node, &iot->tree);
+ kfree(data);
+ }
+}
+
+/*
+ * Note: called from kernel/cgroup.c with cgroup_lock() held.
+ */
+static struct cgroup_subsys_state *iothrottle_create(
+ struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ struct iothrottle *iot;
+
+ iot = kmalloc(sizeof(*iot), GFP_KERNEL);
+ if (unlikely(!iot))
+ return ERR_PTR(-ENOMEM);
+
+ spin_lock_init(&iot->lock);
+ iot->tree = RB_ROOT;
+
+ return &iot->css;
+}
+
+/*
+ * Note: called from kernel/cgroup.c with cgroup_lock() held.
+ */
+static void iothrottle_destroy(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ struct iothrottle_node *data;
+ struct rb_node *next;
+ struct iothrottle *iot = cgroup_to_iothrottle(cont);
+
+ next = rb_first(&iot->tree);
+ while (next) {
+ data = rb_entry(next, struct iothrottle_node, node);
+ next = rb_next(&data->node);
+ rb_erase(&data->node, &iot->tree);
+ kfree(data);
+ }
+ kfree(iot);
+}
+
+static ssize_t iothrottle_read(struct cgroup *cont,
+ struct cftype *cft,
+ struct file *file,
+ char __user *userbuf,
+ size_t nbytes,
+ loff_t *ppos)
+{
+ struct iothrottle *iot;
+ char *buffer, *s;
+ struct rb_node *n;
+ ssize_t ret;
+
+ buffer = kmalloc(nbytes + 1, GFP_KERNEL);
+ if (unlikely(!buffer))
+ return -ENOMEM;
+
+ cgroup_lock();
+ if (cgroup_is_removed(cont)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ iot = cgroup_to_iothrottle(cont);
+
+ s = buffer;
+ spin_lock_irq(&iot->lock);
+ iothrottle_for_each(n, &iot->tree) {
+ struct iothrottle_node *node =
+ rb_entry(n, struct iothrottle_node, node);
+ unsigned long delta = (long)jiffies - (long)node->last_request;
+
+ BUG_ON(!node->dev);
+ s += snprintf(s, nbytes - (s - buffer),
+ "=== device (%u,%u) ===\n"
+ "bandwidth-max: %lu KiB/sec\n"
+ " requested: %lu bytes\n"
+ " last request: %lu jiffies\n"
+ " delta: %lu jiffies\n",
+ MAJOR(node->dev), MINOR(node->dev),
+ node->iorate, node->req,
+ node->last_request, delta);
+ }
+ spin_unlock_irq(&iot->lock);
+ buffer[nbytes] = '\0';
+
+ ret = simple_read_from_buffer(userbuf, nbytes,
+ ppos, buffer, (s - buffer));
+out:
+ cgroup_unlock();
+ kfree(buffer);
+ return ret;
+}
+
+static inline dev_t devname2dev_t(const char *buf)
+{
+ struct block_device *bdev;
+ dev_t ret;
+
+ bdev = lookup_bdev(buf);
+ if (IS_ERR(bdev))
+ return 0;
+
+ BUG_ON(!bdev->bd_inode);
+ ret = bdev->bd_inode->i_rdev;
+ bdput(bdev);
+
+ return ret;
+}
+
+static inline int iothrottle_parse_args(char *buf, size_t nbytes,
+ dev_t *dev, unsigned long *val)
+{
+ char *p;
+
+ p = memchr(buf, ':', nbytes);
+ if (!p)
+ return -EINVAL;
+ *p++ = '\0';
+
+ *dev = devname2dev_t(buf);
+ if (!*dev)
+ return -ENOTBLK;
+
+ return strict_strtoul(p, 10, val);
+}
+
+static ssize_t iothrottle_write(struct cgroup *cont,
+ struct cftype *cft,
+ struct file *file,
+ const char __user *userbuf,
+ size_t nbytes, loff_t *ppos)
+{
+ struct iothrottle *iot;
+ struct iothrottle_node *node, *tmpn = NULL;
+ char *buffer, *tmpp;
+ dev_t dev;
+ unsigned long val;
+ int ret;
+
+ if (unlikely(!nbytes))
+ return -EINVAL;
+
+ buffer = kmalloc(nbytes + 1, GFP_KERNEL);
+ if (unlikely(!buffer))
+ return -ENOMEM;
+
+ if (copy_from_user(buffer, userbuf, nbytes)) {
+ ret = -EFAULT;
+ goto out1;
+ }
+
+ buffer[nbytes] = '\0';
+ tmpp = strstrip(buffer);
+
+ ret = iothrottle_parse_args(tmpp, nbytes, &dev, &val);
+ if (ret)
+ goto out1;
+
+ /*
+ * Pre-allocate a temporary node structure outside locks to use
+ * GFP_KERNEL, it will be kfree()ed later if unused.
+ */
+ tmpn = kmalloc(sizeof(*tmpn), GFP_KERNEL);
+
+ cgroup_lock();
+ if (cgroup_is_removed(cont)) {
+ ret = -ENODEV;
+ goto out2;
+ }
+
+ iot = cgroup_to_iothrottle(cont);
+
+ spin_lock_irq(&iot->lock);
+ if (!val) {
+ /* Delete a block device limiting rule */
+ iothrottle_delete_node(iot, dev);
+ ret = nbytes;
+ goto out3;
+ }
+ node = iothrottle_search_node(iot, dev);
+ if (node) {
+ /* Update a block device limiting rule */
+ node->iorate = val;
+ node->req = 0;
+ node->last_request = jiffies;
+ ret = nbytes;
+ goto out3;
+ }
+ /* Add a new block device limiting rule */
+ if (unlikely(!tmpn)) {
+ ret = -ENOMEM;
+ goto out3;
+ }
+ node = tmpn;
+ tmpn = NULL;
+
+ node->iorate = val;
+ node->req = 0;
+ node->last_request = jiffies;
+ node->dev = dev;
+ ret = iothrottle_insert_node(iot, node);
+ BUG_ON(ret);
+ ret = nbytes;
+out3:
+ spin_unlock_irq(&iot->lock);
+out2:
+ cgroup_unlock();
+ if (tmpn)
+ kfree(tmpn);
+out1:
+ kfree(buffer);
+ return ret;
+}
+
+static struct cftype files[] = {
+ {
+ .name = "bandwidth",
+ .read = iothrottle_read,
+ .write = iothrottle_write,
+ },
+};
+
+static int iothrottle_populate(struct cgroup_subsys *ss, struct cgroup *cont)
+{
+ return cgroup_add_files(cont, ss, files, ARRAY_SIZE(files));
+}
+
+struct cgroup_subsys iothrottle_subsys = {
+ .name = "blockio",
+ .create = iothrottle_create,
+ .destroy = iothrottle_destroy,
+ .populate = iothrottle_populate,
+ .subsys_id = iothrottle_subsys_id,
+};
+
+static inline int __cant_sleep(void)
+{
+ return in_atomic() || in_interrupt() || irqs_disabled();
+}
+
+void cgroup_io_account(struct block_device *bdev, size_t bytes)
+{
+ struct iothrottle *iot;
+ struct iothrottle_node *node;
+ unsigned long delta, t;
+ long sleep;
+
+ if (unlikely(!bdev))
+ return;
+
+ BUG_ON(!bdev->bd_inode);
+
+ iot = task_to_iothrottle(current);
+ if (unlikely(!iot))
+ return;
+
+ spin_lock_irq(&iot->lock);
+
+ node = iothrottle_search_node(iot, bdev->bd_inode->i_rdev);
+ if (!node || !node->iorate)
+ goto out;
+
+ /* Account the I/O activity */
+ node->req += bytes;
+
+ /* Evaluate if we need to throttle the current process */
+ delta = (long)jiffies - (long)node->last_request;
+ if (!delta)
+ goto out;
+
+ t = msecs_to_jiffies(node->req / node->iorate);
+ if (!t)
+ goto out;
+
+ sleep = t - delta;
+ if (unlikely(sleep > 0)) {
+ spin_unlock_irq(&iot->lock);
+ if (__cant_sleep())
+ return;
+ pr_debug("io-throttle: task %p (%s) must sleep %lu jiffies\n",
+ current, current->comm, sleep);
+ schedule_timeout_killable(sleep);
+ return;
+ }
+
+ /* Reset I/O accounting */
+ node->req = 0;
+ node->last_request = jiffies;
+out:
+ spin_unlock_irq(&iot->lock);
+}
+EXPORT_SYMBOL(cgroup_io_account);
diff --git a/include/linux/blk-io-throttle.h b/include/linux/blk-io-throttle.h
new file mode 100644
index 0000000..cff0c13
--- /dev/null
+++ b/include/linux/blk-io-throttle.h
@@ -0,0 +1,12 @@
+#ifndef BLK_IO_THROTTLE_H
+#define BLK_IO_THROTTLE_H
+
+#ifdef CONFIG_CGROUP_IO_THROTTLE
+extern void cgroup_io_account(struct block_device *bdev, size_t bytes);
+#else
+static inline void cgroup_io_account(struct block_device *bdev, size_t bytes)
+{
+}
+#endif /* CONFIG_CGROUP_IO_THROTTLE */
+
+#endif /* BLK_IO_THROTTLE_H */
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index e287745..0caf3c2 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -48,3 +48,9 @@ SUBSYS(devices)
#endif
/* */
+
+#ifdef CONFIG_CGROUP_IO_THROTTLE
+SUBSYS(iothrottle)
+#endif
+
+/* */
diff --git a/init/Kconfig b/init/Kconfig
index 6199d11..3117d99 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -306,6 +306,16 @@ config CGROUP_DEVICE
Provides a cgroup implementing whitelists for devices which
a process in the cgroup can mknod or open.
+config CGROUP_IO_THROTTLE
+ bool "Enable cgroup I/O throttling (EXPERIMENTAL)"
+ depends on CGROUPS && EXPERIMENTAL
+ help
+ This allows to limit the maximum I/O bandwidth for specific
+ cgroup(s).
+ See Documentation/controllers/io-throttle.txt for more information.
+
+ If unsure, say N.
+
config CPUSETS
bool "Cpuset support"
depends on SMP && CGROUPS
--
1.5.4.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists