diff options
| author | Austin Clements <austin@google.com> | 2015-01-30 15:30:41 -0500 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2015-02-02 19:34:51 +0000 |
| commit | 28b51184156e1261bb92e7ec4050a794dd606fa6 (patch) | |
| tree | 8d8659e3e706f687b241e8068ef80ff80987c3d2 /src/runtime/stack1.go | |
| parent | f95becaddb539a45cc9bedbbbc9ee4a2433c1ab5 (diff) | |
| download | go-28b51184156e1261bb92e7ec4050a794dd606fa6.tar.xz | |
runtime: rename m.gcing to m.preemptoff and make it a string
m.gcing has become overloaded to mean "don't preempt this g" in
general. Once the garbage collector is preemptible, the one thing it
*won't* mean is that we're in the garbage collector.
So, rename gcing to "preemptoff" and make it a string giving a reason
that preemption is disabled. gcing was never set to anything but 0 or
1, so we don't have to worry about there being a stack of reasons.
Change-Id: I4337c29e8e942e7aa4f106fc29597e1b5de4ef46
Reviewed-on: https://go-review.googlesource.com/3660
Reviewed-by: Russ Cox <rsc@golang.org>
Diffstat (limited to 'src/runtime/stack1.go')
| -rw-r--r-- | src/runtime/stack1.go | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/src/runtime/stack1.go b/src/runtime/stack1.go index dda39ce481..8ad331777c 100644 --- a/src/runtime/stack1.go +++ b/src/runtime/stack1.go @@ -208,7 +208,7 @@ func stackalloc(n uint32) stack { } var x gclinkptr c := thisg.m.mcache - if c == nil || thisg.m.gcing != 0 || thisg.m.helpgc != 0 { + if c == nil || thisg.m.preemptoff != "" || thisg.m.helpgc != 0 { // c == nil can happen in the guts of exitsyscall or // procresize. Just get a stack from the global pool. // Also don't touch stackcache during gc @@ -271,7 +271,7 @@ func stackfree(stk stack) { } x := gclinkptr(v) c := gp.m.mcache - if c == nil || gp.m.gcing != 0 || gp.m.helpgc != 0 { + if c == nil || gp.m.preemptoff != "" || gp.m.helpgc != 0 { lock(&stackpoolmu) stackpoolfree(x, order) unlock(&stackpoolmu) @@ -648,7 +648,8 @@ func newstack() { // Be conservative about where we preempt. // We are interested in preempting user Go code, not runtime code. - // If we're holding locks, mallocing, or GCing, don't preempt. + // If we're holding locks, mallocing, or preemption is disabled, don't + // preempt. // This check is very early in newstack so that even the status change // from Grunning to Gwaiting and back doesn't happen in this case. // That status change by itself can be viewed as a small preemption, @@ -658,7 +659,7 @@ func newstack() { // it needs a lock held by the goroutine), that small preemption turns // into a real deadlock. if preempt { - if thisg.m.locks != 0 || thisg.m.mallocing != 0 || thisg.m.gcing != 0 || thisg.m.p.status != _Prunning { + if thisg.m.locks != 0 || thisg.m.mallocing != 0 || thisg.m.preemptoff != "" || thisg.m.p.status != _Prunning { // Let the goroutine keep running for now. // gp->preempt is set, so it will be preempted next time. gp.stackguard0 = gp.stack.lo + _StackGuard |