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| author | dumbbell <dumbbell@FreeBSD.org> | 2007-11-19 15:05:20 +0000 |
|---|---|---|
| committer | dumbbell <dumbbell@FreeBSD.org> | 2007-11-19 15:05:20 +0000 |
| commit | fff090c0118c02baeefd12b4413c8503a4ce0d1b (patch) | |
| tree | c63af79f0fa66f231cc8872859c517ee90a409b8 /sys/kern/sys_pipe.c | |
| parent | 764e9c0b5267d42c819658949900c8ad2e0460b7 (diff) | |
| download | FreeBSD-src-fff090c0118c02baeefd12b4413c8503a4ce0d1b.zip FreeBSD-src-fff090c0118c02baeefd12b4413c8503a4ce0d1b.tar.gz | |
The kernel uses two ways to write data on a pipe:
o buffered write, for chunks smaller than PIPE_MINDIRECT bytes
o direct write, for everything else
A call to writev(2) may receive struct iov of various size and the
kernel may have to switch from one solution to the other. Before doing
this, it must wake reader processes and any select/poll/kqueue up.
This commit fixes a bug where select/poll/kqueue are not triggered
when switching from buffered write to direct write. It adds calls to
pipeselwakeup().
I give more details on freebsd-arch@:
http://lists.freebsd.org/pipermail/freebsd-arch/2007-September/006790.html
This should fix issues with Erlang (lang/erlang) and kqueue.
Reported by: Rickard Green (Erlang)
Diffstat (limited to 'sys/kern/sys_pipe.c')
| -rw-r--r-- | sys/kern/sys_pipe.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index 4e3f523..2a48583 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -880,6 +880,7 @@ retry: wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } + pipeselwakeup(wpipe); wpipe->pipe_state |= PIPE_WANTW; pipeunlock(wpipe); error = msleep(wpipe, PIPE_MTX(wpipe), @@ -895,6 +896,7 @@ retry: wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } + pipeselwakeup(wpipe); wpipe->pipe_state |= PIPE_WANTW; pipeunlock(wpipe); error = msleep(wpipe, PIPE_MTX(wpipe), @@ -1080,6 +1082,8 @@ pipe_write(fp, uio, active_cred, flags, td) wpipe->pipe_state &= ~PIPE_WANTR; wakeup(wpipe); } + pipeselwakeup(wpipe); + wpipe->pipe_state |= PIPE_WANTW; pipeunlock(wpipe); error = msleep(wpipe, PIPE_MTX(rpipe), PRIBIO | PCATCH, "pipbww", 0); |
