diff options
| author | Dmitriy Vyukov <dvyukov@google.com> | 2013-07-17 12:52:37 -0400 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2013-07-17 12:52:37 -0400 |
| commit | 5887f142a33fbb8da94088e902ced4101a16aa8f (patch) | |
| tree | 34e4b531885ee16e020a5fc0289a4836f561f7ed /src/pkg/runtime/proc.c | |
| parent | a83748596c009db47bcd35a69531e485e2c7f924 (diff) | |
| download | go-5887f142a33fbb8da94088e902ced4101a16aa8f.tar.xz | |
runtime: more reliable preemption
Currently preemption signal g->stackguard0==StackPreempt
can be lost if it is received when preemption is disabled
(e.g. m->lock!=0). This change duplicates the preemption
signal in g->preempt and restores g->stackguard0
when preemption is enabled.
Update #543.
R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/10792043
Diffstat (limited to 'src/pkg/runtime/proc.c')
| -rw-r--r-- | src/pkg/runtime/proc.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c index fffd04b7fb..3ce281fc77 100644 --- a/src/pkg/runtime/proc.c +++ b/src/pkg/runtime/proc.c @@ -294,6 +294,8 @@ runtime·ready(G *gp) if(runtime·atomicload(&runtime·sched.npidle) != 0 && runtime·atomicload(&runtime·sched.nmspinning) == 0) // TODO: fast atomic wakep(); m->locks--; + if(m->locks == 0 && g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; } int32 @@ -475,6 +477,8 @@ runtime·starttheworld(void) newm(mhelpgc, nil); } m->locks--; + if(m->locks == 0 && g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; } // Called to start an M. @@ -564,6 +568,8 @@ runtime·allocm(P *p) if(p == m->p) releasep(); m->locks--; + if(m->locks == 0 && g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; return mp; } @@ -1008,6 +1014,7 @@ execute(G *gp) runtime·throw("execute: bad g status"); } gp->status = Grunning; + gp->preempt = false; gp->stackguard0 = gp->stackguard; m->p->tick++; m->curg = gp; @@ -1433,6 +1440,8 @@ runtime·exitsyscall(void) // so okay to clear gcstack and gcsp. g->gcstack = (uintptr)nil; g->gcsp = (uintptr)nil; + if(g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; return; } @@ -1450,6 +1459,8 @@ runtime·exitsyscall(void) g->status = Grunning; g->gcstack = (uintptr)nil; g->gcsp = (uintptr)nil; + if(g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; return; } } @@ -1620,6 +1631,8 @@ runtime·newproc1(FuncVal *fn, byte *argp, int32 narg, int32 nret, void *callerp if(runtime·atomicload(&runtime·sched.npidle) != 0 && runtime·atomicload(&runtime·sched.nmspinning) == 0 && fn->fn != runtime·main) // TODO: fast atomic wakep(); m->locks--; + if(m->locks == 0 && g->preempt) // restore the preemption request in case we've cleared it in newstack + g->stackguard0 = StackPreempt; return newg; } @@ -2174,6 +2187,7 @@ if(1) return; gp = mp->curg; if(gp == nil || gp == mp->g0) return; + gp->preempt = true; gp->stackguard0 = StackPreempt; } |