From: Pavel Begunkov <asml.silence@gmail.com>
To: Jens Axboe <axboe@kernel.dk>, io-uring@vger.kernel.org
Subject: [PATCH 2/2] io_uring: return locked and pinned page accounting
Date: Sat, 18 Jul 2020 11:31:21 +0300 [thread overview]
Message-ID: <bb87556b53af8b3dbfc79eae8ee0a90acd328ed7.1595017706.git.asml.silence@gmail.com> (raw)
In-Reply-To: <cover.1595017706.git.asml.silence@gmail.com>
Locked and pinned memory accounting in io_{,un}account_mem() depends on
having ->sqo_mm, which is NULL after a recent change for non SQPOLL'ed
io_ring. That disables the accounting.
Return ->sqo_mm initialisation back, and do __io_sq_thread_acquire_mm()
based on IORING_SETUP_SQPOLL flag.
Fixes: 8eb06d7e8dd85 ("io_uring: fix missing ->mm on exit")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e535152fefab..57e1f26b6a6b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -980,7 +980,8 @@ static void io_sq_thread_drop_mm(void)
static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
{
if (!current->mm) {
- if (unlikely(!ctx->sqo_mm || !mmget_not_zero(ctx->sqo_mm)))
+ if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) ||
+ !mmget_not_zero(ctx->sqo_mm)))
return -EFAULT;
kthread_use_mm(ctx->sqo_mm);
}
@@ -7244,10 +7245,10 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
{
int ret;
- if (ctx->flags & IORING_SETUP_SQPOLL) {
- mmgrab(current->mm);
- ctx->sqo_mm = current->mm;
+ mmgrab(current->mm);
+ ctx->sqo_mm = current->mm;
+ if (ctx->flags & IORING_SETUP_SQPOLL) {
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto err;
--
2.24.0
next prev parent reply other threads:[~2020-07-18 8:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-18 8:31 [PATCH 5.9 0/2] memory accounting fixes Pavel Begunkov
2020-07-18 8:31 ` [PATCH 1/2] io_uring: don't miscount pinned memory Pavel Begunkov
2020-07-18 8:31 ` Pavel Begunkov [this message]
2020-07-18 14:37 ` [PATCH 5.9 0/2] memory accounting fixes Jens Axboe
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