From: Pavel Machek <pavel@ucw.cz>
To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>, Andrew Morton <akpm@osdl.org>,
linux-kernel@vger.kernel.org, nigel@suspend2.net
Subject: vfork makes processes uninterruptible [was Re: [PATCH -mm] swsusp: freeze user space processes first]
Date: Fri, 10 Feb 2006 21:20:00 +0100 [thread overview]
Message-ID: <20060210202000.GB1696@elf.ucw.cz> (raw)
In-Reply-To: <200602051239.53175.rjw@sisk.pl>
Hi!
> > Can you produce userland testcase? If we have uninterruptible process for
> > days... that's a bug in kernel, suspend or not.
>
> Sure, no problem. [Pretty scary, no?]
Yes, pretty scary. It will also raise system load for 300 seconds
without any real load.
> The test code:
>
> #include <sys/types.h>
> #include <unistd.h>
>
> int main(int argc, char *argv[])
> {
> vfork();
> sleep(300);
>
> return 0;
> }
>
> The result:
>
> rafael@albercik:~/programming/c> ./vfork_test &
> [1] 12288
> rafael@albercik:~/programming/c> ps l
> F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
> 0 500 6937 6931 17 0 10048 2368 read_c Ss+ pts/1 0:00 /bin/bash
> 0 500 12139 12133 15 0 10052 2380 wait Ss pts/2 0:00 /bin/bash
> 0 500 12288 12139 15 0 2420 304 fork D pts/2 0:00 ./vfork_tes
> 1 500 12291 12288 18 0 2420 304 hrtime S pts/2 0:00 ./vfork_tes
> 0 500 12372 12139 15 0 3596 820 - R+ pts/2 0:00 ps l
> rafael@albercik:~/programming/c> kill 12288
> rafael@albercik:~/programming/c> ps l
> F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
> 0 500 6937 6931 17 0 10048 2368 read_c Ss+ pts/1 0:00 /bin/bash
> 0 500 12139 12133 15 0 10052 2380 wait Ss pts/2 0:00 /bin/bash
> 0 500 12288 12139 15 0 2420 304 fork D pts/2 0:00 ./vfork_tes
> 1 500 12291 12288 18 0 2420 304 hrtime S pts/2 0:00 ./vfork_tes
> 0 500 12380 12139 17 0 3600 820 - R+ pts/2 0:00 ps l
> rafael@albercik:~/programming/c> kill -9 12288
> rafael@albercik:~/programming/c> ps l
> F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND
> 0 500 6937 6931 17 0 10048 2368 read_c Ss+ pts/1 0:00 /bin/bash
> 0 500 12139 12133 15 0 10052 2380 wait Ss pts/2 0:00 /bin/bash
> 0 500 12288 12139 15 0 2420 304 fork D pts/2 0:00 ./vfork_tes
> 1 500 12291 12288 18 0 2420 304 hrtime S pts/2 0:00 ./vfork_tes
> 0 500 12387 12139 16 0 3596 816 - R+ pts/2 0:00 ps l
> rafael@albercik:~/programming/c>
>
> Greetings,
> Rafael
--
Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted...
next prev parent reply other threads:[~2006-02-10 20:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-02-05 9:14 [PATCH -mm] swsusp: freeze user space processes first Rafael J. Wysocki
2006-02-05 9:38 ` Andrew Morton
2006-02-05 10:34 ` Rafael J. Wysocki
2006-02-05 10:50 ` Ingo Molnar
2006-02-05 11:11 ` Rafael J. Wysocki
2006-02-05 11:18 ` Pavel Machek
2006-02-05 11:39 ` Rafael J. Wysocki
2006-02-05 13:34 ` Rafael J. Wysocki
2006-02-10 20:20 ` Pavel Machek [this message]
2006-02-05 11:11 ` Pavel Machek
2006-02-05 14:22 ` Ingo Molnar
2006-02-10 20:36 ` Pavel Machek
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20060210202000.GB1696@elf.ucw.cz \
--to=pavel@ucw.cz \
--cc=akpm@osdl.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=nigel@suspend2.net \
--cc=rjw@sisk.pl \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome