sleep(3) sometimes too sleepy on FreeBSD 8.0?
freebsd at jdc.parodius.com
Wed Feb 24 11:44:43 UTC 2010
On Wed, Feb 24, 2010 at 01:21:39PM +0200, Kostik Belousov wrote:
> On Wed, Feb 24, 2010 at 06:53:59PM +1100, Peter Jeremy wrote:
> > Updates following some off-line discussions and debugging with John on
> > IRC. I've cc'd gshapiro@ because the problem appears to be sendmail,
> > rather than the FreeBSD kernel.
> > On 2010-Feb-23 12:35:22 +1100, John Marshall <john.marshall at riverwillow.com.au> wrote:
> > >Environment: sendmail 8.14.4 on FreeBSD 8.0-RELEASE-p2
> > Note that this is stock ISC sendmail, not the sendmail in either the
> > base system or the port.
> > >I posted about this in comp.mail.sendmail and was told...
> > >
> > >> sleep() should be one of these calls:
> > >>
> > >> if (njobs == 0 && WorkGrp[wgrp].wg_lowqintvl < MIN_SLEEP_TIME)
> > >> sleep(MIN_SLEEP_TIME);
> > >> else if (WorkGrp[wgrp].wg_lowqintvl <= 0)
> > >> sleep(QueueIntvl > 0 ? QueueIntvl : MIN_SLEEP_TIME);
> > >> else
> > >> sleep(WorkGrp[wgrp].wg_lowqintvl);
> > Whilst it's true that the code calls sleep(), it's not calling
> > sleep(3) in the FreeBSD libc. Instead it's calling a sleep() defined
> > in libsm/clock.c - which is a horrible maze of #ifdefs.
> > John has pre-processed that code and the result it at:
> > http://www.riverwillow.net.au/~john/sm/clock.preprocessed
> > At a quick look, the code is broken: sm_seteventm() generates a
> > one-off timer using setitimer(2), which will send SIGALRM when it
> > expires. sm_releasesignal() then unblocks SIGALRM. In theory, the
> > SIGALRM could be delivered anywhere after the (!SmSleepDone) test and
> > before pause() is called - in which case, the signal is lost and
> > pause() will sleep forever.
> > On 2010-Feb-24 08:13:06 +1100, John Marshall <john.marshall at riverwillow.com.au> wrote:
> > >My ktrace file was created with 'ktrace -g 48501'. I have the result of
> > >'kdump -R -p 48504' available at:
> > >
> > > <http://www.riverwillow.net.au/~john/8_0/rwsrv04_201002240725.kdump.gz>
> I get 'kdump: data too short' on RELENG_8/i386.
Is the OP's machine amd64?
| Jeremy Chadwick jdc at parodius.com |
| Parodius Networking http://www.parodius.com/ |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |
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