Date: Wed, 20 Apr 2011 18:02:42 -0400 From: Ryan Stone <rysto32@gmail.com> To: John Baldwin <jhb@freebsd.org> Cc: freebsd-current@freebsd.org, Ed Maste <emaste@freebsd.org> Subject: Re: sched_4bsd startup crash trying to run a bound thread on an AP that hasn't started Message-ID: <BANLkTin9MgwyZtyiLWJsHbFxv0ihicbiEg@mail.gmail.com> In-Reply-To: <201104061429.50185.jhb@freebsd.org> References: <BANLkTinSyDaY-06N95n8c1NxOSdEnb5FkQ@mail.gmail.com> <201104060836.56542.jhb@freebsd.org> <BANLkTinvisvGiQOs5w-nsxzRVbJUN5%2B5yQ@mail.gmail.com> <201104061429.50185.jhb@freebsd.org>
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On Wed, Apr 6, 2011 at 2:29 PM, John Baldwin <jhb@freebsd.org> wrote:
> I guess one other option would be something like this:
>
> if (smp_started && (td->td_pinned != 0 || td->td_flags & TDF_BOUND ||
> ts->ts_flags & TSF_AFFINITY)) {
> if (td->td_pinned != 0)
> cpu = td->td_lastcpu;
> else if (td->td_flags & TDF_BOUND) {
> /* Find CPU from bound runq. */
> KASSERT(...);
> cpu = ts->ts_runq - &runq_pcpu[0];
> } else
> /* Find a valid CPU for our cpuset. */
> cpu = sched_pickcpu(td);
> ts->ts_runq = &runq_pcpu[cpu];
> single_cpu = 1;
> CTR3(KTR_RUNQ, ...);
> } else {
> /* Global runq case. */
> }
>
> This also avoids duplicating some common code to all the single_cpu cases.
>
> --
> John Baldwin
>
I went with this option. Does this look right?
Index: sys/kern/sched_4bsd.c
===================================================================
--- sys/kern/sched_4bsd.c (revision 220603)
+++ sys/kern/sched_4bsd.c (working copy)
@@ -1246,30 +1246,28 @@
}
TD_SET_RUNQ(td);
- if (td->td_pinned != 0) {
- cpu = td->td_lastcpu;
+ /*
+ * If SMP is not started, don't obey any requested CPU pinning as that
+ * CPU has either not yet started or it is curcpu. Trying to run a
+ * thread on a CPU that has not yet started will panic the system.
+ */
+ if (smp_started && (td->td_pinned != 0 || td->td_flags & TDF_BOUND ||
+ ts->ts_flags & TSF_AFFINITY)) {
+ if (td->td_pinned != 0)
+ cpu = td->td_lastcpu;
+ else if (td->td_flags & TDF_BOUND) {
+ /* Find CPU from bound runq. */
+ KASSERT(SKE_RUNQ_PCPU(ts),
+ ("sched_add: bound td_sched not on cpu runq"));
+ cpu = ts->ts_runq - &runq_pcpu[0];
+ } else
+ /* Find a valid CPU for our cpuset */
+ cpu = sched_pickcpu(td);
ts->ts_runq = &runq_pcpu[cpu];
single_cpu = 1;
CTR3(KTR_RUNQ,
"sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td,
cpu);
- } else if (td->td_flags & TDF_BOUND) {
- /* Find CPU from bound runq. */
- KASSERT(SKE_RUNQ_PCPU(ts),
- ("sched_add: bound td_sched not on cpu runq"));
- cpu = ts->ts_runq - &runq_pcpu[0];
- single_cpu = 1;
- CTR3(KTR_RUNQ,
- "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td,
- cpu);
- } else if (ts->ts_flags & TSF_AFFINITY) {
- /* Find a valid CPU for our cpuset */
- cpu = sched_pickcpu(td);
- ts->ts_runq = &runq_pcpu[cpu];
- single_cpu = 1;
- CTR3(KTR_RUNQ,
- "sched_add: Put td_sched:%p(td:%p) on cpu%d runq", ts, td,
- cpu);
} else {
CTR2(KTR_RUNQ,
"sched_add: adding td_sched:%p (td:%p) to gbl runq", ts,
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