* [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events
@ 2019-05-16 3:46 Jackie Liu
2019-05-16 3:46 ` [PATCH 2/2] io_uring: use wait_event_interruptible for cq_wait conditional wait Jackie Liu
2019-05-16 14:12 ` [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jens Axboe
0 siblings, 2 replies; 4+ messages in thread
From: Jackie Liu @ 2019-05-16 3:46 UTC (permalink / raw)
To: axboe; +Cc: linux-block, Jackie Liu
Whenever smp_rmb is required to use io_cqring_events,
keep smp_rmb inside the function io_cqring_events.
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
fs/io_uring.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 84efb89..516f036 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2044,6 +2044,8 @@ static int io_ring_submit(struct io_ring_ctx *ctx, unsigned int to_submit)
static unsigned io_cqring_events(struct io_cq_ring *ring)
{
+ /* See comment at the top of this file */
+ smp_rmb();
return READ_ONCE(ring->r.tail) - READ_ONCE(ring->r.head);
}
@@ -2059,8 +2061,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
DEFINE_WAIT(wait);
int ret;
- /* See comment at the top of this file */
- smp_rmb();
if (io_cqring_events(ring) >= min_events)
return 0;
@@ -2082,8 +2082,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);
ret = 0;
- /* See comment at the top of this file */
- smp_rmb();
if (io_cqring_events(ring) >= min_events)
break;
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [PATCH 2/2] io_uring: use wait_event_interruptible for cq_wait conditional wait
2019-05-16 3:46 [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jackie Liu
@ 2019-05-16 3:46 ` Jackie Liu
2019-05-16 14:12 ` Jens Axboe
2019-05-16 14:12 ` [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jens Axboe
1 sibling, 1 reply; 4+ messages in thread
From: Jackie Liu @ 2019-05-16 3:46 UTC (permalink / raw)
To: axboe; +Cc: linux-block, Jackie Liu
The previous patch has ensured that io_cqring_events contain
smp_rmb memory barriers, Now we can use wait_event_interruptible
to keep the code simple.
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
fs/io_uring.c | 17 ++---------------
1 file changed, 2 insertions(+), 15 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 516f036..45df0b4 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2058,7 +2058,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
{
struct io_cq_ring *ring = ctx->cq_ring;
sigset_t ksigmask, sigsaved;
- DEFINE_WAIT(wait);
int ret;
if (io_cqring_events(ring) >= min_events)
@@ -2078,21 +2077,9 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
return ret;
}
- do {
- prepare_to_wait(&ctx->wait, &wait, TASK_INTERRUPTIBLE);
-
- ret = 0;
- if (io_cqring_events(ring) >= min_events)
- break;
-
- schedule();
-
+ ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);
+ if (ret == -ERESTARTSYS)
ret = -EINTR;
- if (signal_pending(current))
- break;
- } while (1);
-
- finish_wait(&ctx->wait, &wait);
if (sig)
restore_user_sigmask(sig, &sigsaved);
--
2.7.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events
2019-05-16 3:46 [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jackie Liu
2019-05-16 3:46 ` [PATCH 2/2] io_uring: use wait_event_interruptible for cq_wait conditional wait Jackie Liu
@ 2019-05-16 14:12 ` Jens Axboe
1 sibling, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2019-05-16 14:12 UTC (permalink / raw)
To: Jackie Liu; +Cc: linux-block
On 5/15/19 9:46 PM, Jackie Liu wrote:
> Whenever smp_rmb is required to use io_cqring_events,
> keep smp_rmb inside the function io_cqring_events.
Nice cleanup. Applied, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-05-16 14:12 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2019-05-16 3:46 [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jackie Liu
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2019-05-16 14:12 ` Jens Axboe
2019-05-16 14:12 ` [PATCH 1/2] io_uring: adjust smp_rmb inside io_cqring_events Jens Axboe
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