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* [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd
@ 2022-12-15 18:41 Dylan Yudaken
  2022-12-15 18:44 ` Paul E. McKenney
  2022-12-15 18:49 ` Jens Axboe
  0 siblings, 2 replies; 4+ messages in thread
From: Dylan Yudaken @ 2022-12-15 18:41 UTC (permalink / raw)
  To: Jens Axboe, Pavel Begunkov
  Cc: io-uring, linux-kernel, kernel-team, Dylan Yudaken,
	Joel Fernandes, Paul E . McKenney

io_uring uses call_rcu in the case it needs to signal an eventfd as a
result of an eventfd signal, since recursing eventfd signals are not
allowed. This should be calling the new call_rcu_hurry API to not delay
the signal.

Signed-off-by: Dylan Yudaken <[email protected]>

Cc: Joel Fernandes (Google) <[email protected]>
Cc: Paul E. McKenney <[email protected]>
---
 io_uring/io_uring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index b521186efa5c..2cb8c665bab1 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -538,7 +538,7 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
 	} else {
 		atomic_inc(&ev_fd->refs);
 		if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops))
-			call_rcu(&ev_fd->rcu, io_eventfd_ops);
+			call_rcu_hurry(&ev_fd->rcu, io_eventfd_ops);
 		else
 			atomic_dec(&ev_fd->refs);
 	}

base-commit: 041fae9c105ae342a4245cf1e0dc56a23fbb9d3c
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd
  2022-12-15 18:41 [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd Dylan Yudaken
@ 2022-12-15 18:44 ` Paul E. McKenney
  2022-12-15 18:49 ` Jens Axboe
  1 sibling, 0 replies; 4+ messages in thread
From: Paul E. McKenney @ 2022-12-15 18:44 UTC (permalink / raw)
  To: Dylan Yudaken
  Cc: Jens Axboe, Pavel Begunkov, io-uring, linux-kernel, kernel-team,
	Joel Fernandes

On Thu, Dec 15, 2022 at 10:41:38AM -0800, Dylan Yudaken wrote:
> io_uring uses call_rcu in the case it needs to signal an eventfd as a
> result of an eventfd signal, since recursing eventfd signals are not
> allowed. This should be calling the new call_rcu_hurry API to not delay
> the signal.
> 
> Signed-off-by: Dylan Yudaken <[email protected]>
> 
> Cc: Joel Fernandes (Google) <[email protected]>
> Cc: Paul E. McKenney <[email protected]>

Looks good!

Acked-by: Paul E. McKenney <[email protected]>

> ---
>  io_uring/io_uring.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
> index b521186efa5c..2cb8c665bab1 100644
> --- a/io_uring/io_uring.c
> +++ b/io_uring/io_uring.c
> @@ -538,7 +538,7 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
>  	} else {
>  		atomic_inc(&ev_fd->refs);
>  		if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops))
> -			call_rcu(&ev_fd->rcu, io_eventfd_ops);
> +			call_rcu_hurry(&ev_fd->rcu, io_eventfd_ops);
>  		else
>  			atomic_dec(&ev_fd->refs);
>  	}
> 
> base-commit: 041fae9c105ae342a4245cf1e0dc56a23fbb9d3c
> -- 
> 2.30.2
> 

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd
  2022-12-15 18:41 [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd Dylan Yudaken
  2022-12-15 18:44 ` Paul E. McKenney
@ 2022-12-15 18:49 ` Jens Axboe
  2022-12-15 18:51   ` Joel Fernandes
  1 sibling, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2022-12-15 18:49 UTC (permalink / raw)
  To: Pavel Begunkov, Dylan Yudaken
  Cc: io-uring, linux-kernel, kernel-team, Joel Fernandes,
	Paul E . McKenney


On Thu, 15 Dec 2022 10:41:38 -0800, Dylan Yudaken wrote:
> io_uring uses call_rcu in the case it needs to signal an eventfd as a
> result of an eventfd signal, since recursing eventfd signals are not
> allowed. This should be calling the new call_rcu_hurry API to not delay
> the signal.
> 
> Signed-off-by: Dylan Yudaken <[email protected]>
> 
> [...]

Applied, thanks!

[1/1] io_uring: use call_rcu_hurry if signaling an eventfd
      commit: de8f0209fe8064172a86a61537a7b21d6e5334ad

Best regards,
-- 
Jens Axboe



^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd
  2022-12-15 18:49 ` Jens Axboe
@ 2022-12-15 18:51   ` Joel Fernandes
  0 siblings, 0 replies; 4+ messages in thread
From: Joel Fernandes @ 2022-12-15 18:51 UTC (permalink / raw)
  To: Jens Axboe
  Cc: Pavel Begunkov, Dylan Yudaken, io-uring, linux-kernel,
	kernel-team, Paul E . McKenney

On Thu, Dec 15, 2022 at 1:49 PM Jens Axboe <[email protected]> wrote:
>
>
> On Thu, 15 Dec 2022 10:41:38 -0800, Dylan Yudaken wrote:
> > io_uring uses call_rcu in the case it needs to signal an eventfd as a
> > result of an eventfd signal, since recursing eventfd signals are not
> > allowed. This should be calling the new call_rcu_hurry API to not delay
> > the signal.
> >
> > Signed-off-by: Dylan Yudaken <[email protected]>
> >
> > [...]
>
> Applied, thanks!
>
> [1/1] io_uring: use call_rcu_hurry if signaling an eventfd
>       commit: de8f0209fe8064172a86a61537a7b21d6e5334ad

Reviewed-by: Joel Fernandes (Google) <[email protected]>

thanks,

 - Joel

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-12-15 18:52 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2022-12-15 18:41 [PATCH] io_uring: use call_rcu_hurry if signaling an eventfd Dylan Yudaken
2022-12-15 18:44 ` Paul E. McKenney
2022-12-15 18:49 ` Jens Axboe
2022-12-15 18:51   ` Joel Fernandes

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