On Tuesday 12 December 2006 20:22, Dmitriy Kirhlarov wrote: > On Thu, Dec 07, 2006 at 11:18:52AM +0800, David Xu wrote: > > On Thursday 16 November 2006 19:15, Gleb Smirnoff wrote: > > > On Thu, Nov 16, 2006 at 01:24:36PM +0300, Gleb Smirnoff wrote: > > > T> I wonder why UMA was suspected to be the problem. Dima gave > > > T> me access to the core. Here are more details from the trace: > > > > > > It looks like a race between two threads in one process. Look here: > > > > Can you try the patch ? > > http://people.freebsd.org/~davidxu/patch/ksegrp_preempt.patch > > I've tested it. This patch works also, but with a little bit different > behaviour. With patch from jhb@ I got LA 7-8, with this patch I have > LA 5-6, same as on unpatched system. But it seems to me, that system > is less interactive, compared to jhb@ patch. > > WBR > Dmitriy
jhb patch is incomplete, it implies that every place a thread is doing state transition and waking another thread up should be patched, there is other code in kern_sig.c unpatched, though I don't know other places, but the code maybe_preempt_in_ksegrp should be synced with maybe_preempt, it should fix all problems. the LA you have seen is lower than jhb might be a nature of KSEGRP, but I am not sure, if you program forces all threads to be system-scope, it might fix the problem. David Xu _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"