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Message-Id: <9f63cf4ab74d6e56e434c1c3d7c98352bb282895.1674538665.git-series.apopple@nvidia.com>
Date: Tue, 24 Jan 2023 16:42:38 +1100
From: Alistair Popple <apopple@...dia.com>
To: linux-mm@...ck.org, cgroups@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, jgg@...dia.com, jhubbard@...dia.com,
tjmercier@...gle.com, hannes@...xchg.org, surenb@...gle.com,
mkoutny@...e.com, daniel@...ll.ch,
Alistair Popple <apopple@...dia.com>,
Jens Axboe <axboe@...nel.dk>,
Pavel Begunkov <asml.silence@...il.com>,
io-uring@...r.kernel.org
Subject: [RFC PATCH 09/19] io_uring: convert to use vm_account
Convert io_uring to use vm_account instead of directly charging pages
against the user/mm. Rather than charge pages to both user->locked_vm
and mm->pinned_vm this will only charge pages to user->locked_vm.
Signed-off-by: Alistair Popple <apopple@...dia.com>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Pavel Begunkov <asml.silence@...il.com>
Cc: io-uring@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
---
include/linux/io_uring_types.h | 3 +--
io_uring/io_uring.c | 20 +++---------------
io_uring/notif.c | 4 ++--
io_uring/notif.h | 10 +++------
io_uring/rsrc.c | 38 +++--------------------------------
io_uring/rsrc.h | 9 +--------
6 files changed, 16 insertions(+), 68 deletions(-)
diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 128a67a..d81aceb 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -343,8 +343,7 @@ struct io_ring_ctx {
struct io_wq_hash *hash_map;
/* Only used for accounting purposes */
- struct user_struct *user;
- struct mm_struct *mm_account;
+ struct vm_account vm_account;
/* ctx exit and cancelation */
struct llist_head fallback_llist;
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 0a4efad..912da4f 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2744,15 +2744,11 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));
- if (ctx->mm_account) {
- mmdrop(ctx->mm_account);
- ctx->mm_account = NULL;
- }
+ vm_account_release(&ctx->vm_account);
io_mem_free(ctx->rings);
io_mem_free(ctx->sq_sqes);
percpu_ref_exit(&ctx->refs);
- free_uid(ctx->user);
io_req_caches_free(ctx);
if (ctx->hash_map)
io_wq_put_hash(ctx->hash_map);
@@ -3585,8 +3581,9 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
ctx->syscall_iopoll = 1;
ctx->compat = in_compat_syscall();
- if (!capable(CAP_IPC_LOCK))
- ctx->user = get_uid(current_user());
+ vm_account_init(&ctx->vm_account, current, current_user(),
+ VM_ACCOUNT_USER |
+ (capable(CAP_IPC_LOCK) ? VM_ACCOUNT_BYPASS : 0));
/*
* For SQPOLL, we just need a wakeup, always. For !SQPOLL, if
@@ -3619,15 +3616,6 @@ static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
goto err;
}
- /*
- * This is just grabbed for accounting purposes. When a process exits,
- * the mm is exited and dropped before the files, hence we need to hang
- * on to this mm purely for the purposes of being able to unaccount
- * memory (locked/pinned vm). It's not used for anything else.
- */
- mmgrab(current->mm);
- ctx->mm_account = current->mm;
-
ret = io_allocate_scq_urings(ctx, p);
if (ret)
goto err;
diff --git a/io_uring/notif.c b/io_uring/notif.c
index c4bb793..0f589fa 100644
--- a/io_uring/notif.c
+++ b/io_uring/notif.c
@@ -17,8 +17,8 @@ static void io_notif_complete_tw_ext(struct io_kiocb *notif, bool *locked)
if (nd->zc_report && (nd->zc_copied || !nd->zc_used))
notif->cqe.res |= IORING_NOTIF_USAGE_ZC_COPIED;
- if (nd->account_pages && ctx->user) {
- __io_unaccount_mem(ctx->user, nd->account_pages);
+ if (nd->account_pages) {
+ vm_unaccount_pinned(&ctx->vm_account, nd->account_pages);
nd->account_pages = 0;
}
io_req_task_complete(notif, locked);
diff --git a/io_uring/notif.h b/io_uring/notif.h
index c88c800..e2cb44a 100644
--- a/io_uring/notif.h
+++ b/io_uring/notif.h
@@ -43,11 +43,9 @@ static inline int io_notif_account_mem(struct io_kiocb *notif, unsigned len)
unsigned nr_pages = (len >> PAGE_SHIFT) + 2;
int ret;
- if (ctx->user) {
- ret = __io_account_mem(ctx->user, nr_pages);
- if (ret)
- return ret;
- nd->account_pages += nr_pages;
- }
+ ret = __io_account_mem(&ctx->vm_account, nr_pages);
+ if (ret)
+ return ret;
+ nd->account_pages += nr_pages;
return 0;
}
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 18de10c..aa44528 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -42,49 +42,19 @@ void io_rsrc_refs_drop(struct io_ring_ctx *ctx)
}
}
-int __io_account_mem(struct user_struct *user, unsigned long nr_pages)
+int __io_account_mem(struct vm_account *vm_account, unsigned long nr_pages)
{
- unsigned long page_limit, cur_pages, new_pages;
-
- if (!nr_pages)
- return 0;
-
- /* Don't allow more pages than we can safely lock */
- page_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
-
- cur_pages = atomic_long_read(&user->locked_vm);
- do {
- new_pages = cur_pages + nr_pages;
- if (new_pages > page_limit)
- return -ENOMEM;
- } while (!atomic_long_try_cmpxchg(&user->locked_vm,
- &cur_pages, new_pages));
- return 0;
+ return vm_account_pinned(vm_account, nr_pages);
}
static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
{
- if (ctx->user)
- __io_unaccount_mem(ctx->user, nr_pages);
-
- if (ctx->mm_account)
- atomic64_sub(nr_pages, &ctx->mm_account->pinned_vm);
+ vm_unaccount_pinned(&ctx->vm_account, nr_pages);
}
static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
{
- int ret;
-
- if (ctx->user) {
- ret = __io_account_mem(ctx->user, nr_pages);
- if (ret)
- return ret;
- }
-
- if (ctx->mm_account)
- atomic64_add(nr_pages, &ctx->mm_account->pinned_vm);
-
- return 0;
+ return vm_account_pinned(&ctx->vm_account, nr_pages);
}
static int io_copy_iov(struct io_ring_ctx *ctx, struct iovec *dst,
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 2b87436..d8833d0 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -167,12 +167,5 @@ static inline u64 *io_get_tag_slot(struct io_rsrc_data *data, unsigned int idx)
int io_files_update(struct io_kiocb *req, unsigned int issue_flags);
int io_files_update_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
-int __io_account_mem(struct user_struct *user, unsigned long nr_pages);
-
-static inline void __io_unaccount_mem(struct user_struct *user,
- unsigned long nr_pages)
-{
- atomic_long_sub(nr_pages, &user->locked_vm);
-}
-
+int __io_account_mem(struct vm_account *vm_account, unsigned long nr_pages);
#endif
--
git-series 0.9.1
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