Date: Wed, 29 Nov 2017 17:55:19 -0800 From: Cy Schubert <Cy.Schubert@komquats.com> To: Hans Petter Selasky <hselasky@FreeBSD.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r326376 - head/sys/kern Message-ID: <201711300156.vAU1tJfe070900@slippy.cwsent.com> In-Reply-To: Message from Hans Petter Selasky <hselasky@FreeBSD.org> of "Wed, 29 Nov 2017 23:28:40 %2B0000." <201711292328.vATNSeOM046518@repo.freebsd.org>
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In message <201711292328.vATNSeOM046518@repo.freebsd.org>, Hans Petter Selasky writes: > Author: hselasky > Date: Wed Nov 29 23:28:40 2017 > New Revision: 326376 > URL: https://svnweb.freebsd.org/changeset/base/326376 > > Log: > The sched_add() function is not only used when the thread is initially > started, but also by the turnstiles to mark a thread as runnable for > all locks, for instance sleepqueues do: > setrunnable()->sched_wakeup()->sched_add() > > In r326218 code was added to allow booting from non-zero CPU numbers > by setting the ts_cpu field inside the ULE scheduler's sched_add() > function. This had an undesired side-effect that prior sched_pin() and > sched_bind() calls got disregarded. This patch fixes the > initialization of the ts_cpu field for the ULE scheduler to only > happen once when the initial thread is constructed during system > init. Forking will then later on ensure that a valid ts_cpu value gets > copied to all children. > > Reviewed by: jhb, kib > Discussed with: nwhitehorn > MFC after: 1 month > Differential revision: https://reviews.freebsd.org/D13298 > Sponsored by: Mellanox Technologies > > Modified: > head/sys/kern/sched_ule.c > > Modified: head/sys/kern/sched_ule.c > ============================================================================= > = > --- head/sys/kern/sched_ule.c Wed Nov 29 21:16:14 2017 (r326375) > +++ head/sys/kern/sched_ule.c Wed Nov 29 23:28:40 2017 (r326376) > @@ -1405,7 +1405,6 @@ sched_setup(void *dummy) > > /* Add thread0's load since it's running. */ > TDQ_LOCK(tdq); > - td_get_sched(&thread0)->ts_cpu = curcpu; /* Something valid to start */ > thread0.td_lock = TDQ_LOCKPTR(TDQ_SELF()); > tdq_load_add(tdq, &thread0); > tdq->tdq_lowpri = thread0.td_priority; > @@ -1642,6 +1641,7 @@ schedinit(void) > ts0->ts_ltick = ticks; > ts0->ts_ftick = ticks; > ts0->ts_slice = 0; > + ts0->ts_cpu = curcpu; /* set valid CPU number */ > } > > /* > @@ -2453,7 +2453,6 @@ sched_add(struct thread *td, int flags) > * Pick the destination cpu and if it isn't ours transfer to the > * target cpu. > */ > - td_get_sched(td)->ts_cpu = curcpu; /* Pick something valid to start */ > cpu = sched_pickcpu(td, flags); > tdq = sched_setcpu(td, cpu, flags); > tdq_add(tdq, td, flags); > Thank you. -- Cheers, Cy Schubert <Cy.Schubert@cschubert.com> FreeBSD UNIX: <cy@FreeBSD.org> Web: http://www.FreeBSD.org The need of the many outweighs the greed of the few.
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