From: Cyril Hrubis <chrubis@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH/RFC] tst_process_state_wait: wait for schedstats to settle when state == S
Date: Thu, 7 Nov 2019 13:15:20 +0100 [thread overview]
Message-ID: <20191107121520.GC22352@rei.lan> (raw)
In-Reply-To: <598814762.10700788.1573034381847.JavaMail.zimbra@redhat.com>
Hi!
> hb->lock is locked at this point, and requeue takes it too, so I'm not
> sure what makes it fail. I've seen testcase fail in at least
> 2 different ways now. Here's the other one:
Here is another theory, some of the processes may be sleeping in a
different place in the kernel, somewhere between the fork() and the
futex(), and hence we think that they have been suspended on the futex
but aren't.
I guess that what we can do is to put a counter in a piece of shared
memory and increment it from each child just before the futex_wait()
call and wait in the parent until the counter reached num_waiters.
--
Cyril Hrubis
chrubis@suse.cz
next prev parent reply other threads:[~2019-11-07 12:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-05 11:57 [LTP] [PATCH/RFC] tst_process_state_wait: wait for schedstats to settle when state == S Jan Stancek
2019-11-06 9:59 ` Jan Stancek
2019-11-07 11:39 ` Cyril Hrubis
2019-11-07 12:03 ` Cyril Hrubis
2019-11-07 12:15 ` Cyril Hrubis [this message]
2019-11-07 12:31 ` Jan Stancek
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