On Tuesday, 3 April 2007 14:01, Gautham R Shenoy wrote: > On Mon, Apr 02, 2007 at 08:16:12AM +0200, Ingo Molnar wrote: > > > > i'm wondering about how TASK_UNINTERRUPTIBLE tasks are handled by the > > freezer: are they assumed frozen immediately, or do we wait until they > > notice their PF_FREEZING and go into try_to_freeze()? I'd expect > > TASK_UNINTERRUPTIBLE to be the largest source of latency. (and hence be > > the primary source for freezing 'failures') > > Ok, we might be in some luck. I panic()ed on freezer fail and checked > the stacktrace of the unfrozen tasks. The stacktrace of each one looks > like: > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > PID: 7697 TASK: cc354a70 CPU: 7 COMMAND: "make" > #0 [cc37fe50] schedule at c0431752 > #1 [cc37fec4] wait_for_completion at c04318d0 > #2 [cc37ff24] do_fork at c01249a6 > #3 [cc37ff94] sys_vfork at c0103c1f > #4 [cc37ffb4] system_call at c0104d8d > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Rafael had sent out a patch to fix the vfork race, which can be found at > http://lkml.org/lkml/2007/3/1/212 > > However, the hunk > > @@ -1393,7 +1394,9 @@ long do_fork(unsigned long clone_flags, > tracehook_report_clone_complete(clone_flags, nr, p); > > if (clone_flags & CLONE_VFORK) { > + freezer_do_not_count(); > wait_for_completion(&vfork); > + freezer_count(); > tracehook_report_vfork_done(p, nr); > } > } else { > > Seems to be missing in the latest -mm's.
Good catch! > Rafael / Andrew, > Any reasons for leaving this hunk out? No, absolutely not. It's needed. Moreover, freezer-fix-vfork-problem.patch from the broken-out -rc5-mm3 contains it, so some other patch must have reverted this change. [looks] Ah, it's utrace-prep-2.patch . Andrew? - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
