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author | Soheil Hassas Yeganeh <soheil@google.com> | 2020-12-18 23:02:00 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-19 20:18:38 +0100 |
commit | e8c85328b1e88f4ee7f84a1fdbff2f2c7965e026 (patch) | |
tree | a1a3e3ac13780408cecc2ef0e2e264e35e1f8b5f /fs/eventpoll.c | |
parent | epoll: simplify and optimize busy loop logic (diff) | |
download | linux-e8c85328b1e88f4ee7f84a1fdbff2f2c7965e026.tar.xz linux-e8c85328b1e88f4ee7f84a1fdbff2f2c7965e026.zip |
epoll: pull all code between fetch_events and send_event into the loop
This is a no-op change which simplifies the follow up patches.
Link: https://lkml.kernel.org/r/20201106231635.3528496-7-soheil.kdev@gmail.com
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Khazhismel Kumykov <khazhy@google.com>
Cc: Guantao Liu <guantaol@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/eventpoll.c')
-rw-r--r-- | fs/eventpoll.c | 41 |
1 files changed, 21 insertions, 20 deletions
diff --git a/fs/eventpoll.c b/fs/eventpoll.c index 03d0ac076a16..63a7a6e13dfc 100644 --- a/fs/eventpoll.c +++ b/fs/eventpoll.c @@ -1774,14 +1774,14 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events, } fetch_events: - eavail = ep_events_available(ep); - if (!eavail) - eavail = ep_busy_loop(ep, timed_out); + do { + eavail = ep_events_available(ep); + if (!eavail) + eavail = ep_busy_loop(ep, timed_out); - if (eavail) - goto send_events; + if (eavail) + goto send_events; - do { if (signal_pending(current)) return -EINTR; @@ -1830,21 +1830,22 @@ fetch_events: * carefully under lock, below. */ eavail = 1; - } while (0); - if (!list_empty_careful(&wait.entry)) { - write_lock_irq(&ep->lock); - /* - * If the thread timed out and is not on the wait queue, it - * means that the thread was woken up after its timeout expired - * before it could reacquire the lock. Thus, when wait.entry is - * empty, it needs to harvest events. - */ - if (timed_out) - eavail = list_empty(&wait.entry); - __remove_wait_queue(&ep->wq, &wait); - write_unlock_irq(&ep->lock); - } + if (!list_empty_careful(&wait.entry)) { + write_lock_irq(&ep->lock); + /* + * If the thread timed out and is not on the wait queue, + * it means that the thread was woken up after its + * timeout expired before it could reacquire the lock. + * Thus, when wait.entry is empty, it needs to harvest + * events. + */ + if (timed_out) + eavail = list_empty(&wait.entry); + __remove_wait_queue(&ep->wq, &wait); + write_unlock_irq(&ep->lock); + } + } while (0); send_events: /* |