From: Jackie Liu <liuyun01@kylinos.cn>
To: axboe@kernel.dk
Cc: liuyun01@kylinos.cn, linux-block@vger.kernel.org
Subject: [PATCH] io_uring: set -EINTR directly when a signal wakes up in io_cqring_wait
Date: Tue, 29 Oct 2019 11:16:42 +0800 [thread overview]
Message-ID: <1572319002-9943-1-git-send-email-liuyun01@kylinos.cn> (raw)
We didn't use -ERESTARTSYS to tell the application layer to restart the
system call, but instead return -EINTR. we can set -EINTR directly when
wakeup by the signal, which can help us save an assignment operation and
comparison operation.
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
---
fs/io_uring.c | 9 +++------
1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index a30c4f6..63eee7e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2878,7 +2878,7 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
.to_wait = min_events,
};
struct io_rings *rings = ctx->rings;
- int ret;
+ int ret = 0;
if (io_cqring_events(rings) >= min_events)
return 0;
@@ -2896,7 +2896,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
return ret;
}
- ret = 0;
iowq.nr_timeouts = atomic_read(&ctx->cq_timeouts);
do {
prepare_to_wait_exclusive(&ctx->wait, &iowq.wq,
@@ -2905,15 +2904,13 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,
break;
schedule();
if (signal_pending(current)) {
- ret = -ERESTARTSYS;
+ ret = -EINTR;
break;
}
} while (1);
finish_wait(&ctx->wait, &iowq.wq);
- restore_saved_sigmask_unless(ret == -ERESTARTSYS);
- if (ret == -ERESTARTSYS)
- ret = -EINTR;
+ restore_saved_sigmask_unless(ret == -EINTR);
return READ_ONCE(rings->cq.head) == READ_ONCE(rings->cq.tail) ? ret : 0;
}
--
2.7.4
next reply other threads:[~2019-10-29 3:17 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-29 3:16 Jackie Liu [this message]
2019-11-01 2:14 ` [PATCH] io_uring: set -EINTR directly when a signal wakes up in io_cqring_wait Bob Liu
2019-11-01 14:37 ` Jens Axboe
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