From: Cyril Hrubis <chrubis@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH 5/5] open_posix: condvar/schedule: mask SIGALRM in SCHED_OTHER threads
Date: Mon, 22 Feb 2016 17:09:03 +0100 [thread overview]
Message-ID: <20160222160903.GD7406@rei> (raw)
In-Reply-To: <8f6acea2f6a6b01ebe1749926cbcdbbfd635787a.1455875648.git.jstancek@redhat.com>
Hi!
> Kernel can deliver signal to any thread (usually it's the main).
> If these tests run on single CPU and signal gets delivered to main
> thread with SCHED_OTHER scheduling class then signal handler won't
> run until RT thread occupying CPU completes. Which happens after
> 5 seconds and test fails.
>
> Mask SIGLARM from SCHED_OTHER (main) thread. Kernel will deliver
> signal to any of RT threads that can handle it.
POSIX explicitly states:
It is not safe to use the pthread_cond_signal() function in a signal
handler that is invoked asynchronously.
I guess that the test could be changed to:
* Lock one high priority thread on cond variable
* Run one low priority thread that does sleep(1) then
calls pthread_cond_signal()
* Run one bussy loop low priority thread
That way we would avoid the signal handlers entirely. What do you think?
--
Cyril Hrubis
chrubis@suse.cz
next prev parent reply other threads:[~2016-02-22 16:09 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-19 10:03 [LTP] [PATCH 1/5] open_posix: add SAFE_PFUNC macro Jan Stancek
2016-02-19 10:03 ` [LTP] [PATCH 2/5] open_posix: condvar/schedule: use SAFE_PFUNC Jan Stancek
2016-02-22 13:42 ` Cyril Hrubis
2016-02-19 10:03 ` [LTP] [PATCH 3/5] open_posix: condvar/schedule: remove useless waiting Jan Stancek
2016-02-22 14:57 ` Cyril Hrubis
2016-02-19 10:03 ` [LTP] [PATCH 4/5] open_posix: condvar/schedule: remove duplicit setsched calls Jan Stancek
2016-02-22 15:38 ` Cyril Hrubis
2016-02-19 10:03 ` [LTP] [PATCH 5/5] open_posix: condvar/schedule: mask SIGALRM in SCHED_OTHER threads Jan Stancek
2016-02-22 16:09 ` Cyril Hrubis [this message]
2016-02-23 7:34 ` Jan Stancek
2016-02-23 10:00 ` Cyril Hrubis
2016-02-23 12:44 ` Jan Stancek
2016-02-22 13:35 ` [LTP] [PATCH 1/5] open_posix: add SAFE_PFUNC macro Cyril Hrubis
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