Attachment 10226 Details for Bug 10779 – git-am fix for 4.1.next and 4.0.next.

[patch] git-am fix for 4.1.next and 4.0.next.

0001-pthreadpool-Slightly-serialize-jobs.patch (text/plain), 2.07 KB, created by Jeremy Allison on 2014-08-25 19:31:09 UTC

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Creator: Jeremy Allison

Created: 2014-08-25 19:31:09 UTC

Size: 2.07 KB

patch

obsolete

>From c02171065cef9de181dccc41be035887d410d9d8 Mon Sep 17 00:00:00 2001
>From: Jeremy Allison <jra@samba.org>
>Date: Mon, 25 Aug 2014 12:27:54 -0700
>Subject: [PATCH] pthreadpool: Slightly serialize jobs
>
>Using the new msg_source program with 1.500 instances against a single
>msg_sink I found the msg_source process to spawn two worker threads for
>synchronously sending the data towards the receiving socket. This should
>not happen: Per destination node we only create one queue. We strictly
>only add pthreadpool jobs one after the other, so a single helper thread
>should be perfectly sufficient.
>
>It turned out that under heavy overload the main sending thread was
>scheduled before the thread that just had finished its send() job. So
>the helper thread was not able to increment the pool->num_idle variable
>indicating that we don't have to create a new thread when the new job
>is added.
>
>This patch moves the signalling write under the mutex. This means that
>indicating readiness via the pipe and the pool->num_idle variable happen both
>under the same mutex lock and thus are atomic. No superfluous threads anymore.
>
>Back port of commit 1c4284c7395f23cefa61a407db74cf5067aee2aa
>that went into master.
>
>https://bugzilla.samba.org/show_bug.cgi?id=10779
>
>Signed-off-by: Volker Lendecke <vl@samba.org>
>Reviewed-by: Jeremy Allison <jra@samba.org>
>---
> source3/lib/pthreadpool/pthreadpool.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
>diff --git a/source3/lib/pthreadpool/pthreadpool.c b/source3/lib/pthreadpool/pthreadpool.c
>index c5c9367..9c781cf 100644
>--- a/source3/lib/pthreadpool/pthreadpool.c
>+++ b/source3/lib/pthreadpool/pthreadpool.c
>@@ -488,14 +488,14 @@ static void *pthreadpool_server(void *arg)
> 
> 			job->fn(job->private_data);
> 
>+			res = pthread_mutex_lock(&pool->mutex);
>+			assert(res == 0);
>+
> 			written = write(pool->sig_pipe[1], &job->id,
> 					sizeof(int));
> 
> 			free(job);
> 
>-			res = pthread_mutex_lock(&pool->mutex);
>-			assert(res == 0);
>-
> 			if (written != sizeof(int)) {
> 				pthreadpool_server_exit(pool);
> 				pthread_mutex_unlock(&pool->mutex);
>-- 
>2.1.0.rc2.206.gedb03e5
>

Flags:

jra: review? (metze)
jra: review? (ddiss)
ira: review+

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Attachments on bug 10779: 10226