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| author | Cherry Zhang <cherryyz@google.com> | 2020-03-16 20:08:00 -0400 |
|---|---|---|
| committer | Cherry Zhang <cherryyz@google.com> | 2020-03-18 16:00:44 +0000 |
| commit | 0c0e8f224d5724e317952f77d215a752a3a7b7d9 (patch) | |
| tree | c190a79fde5ddd44ab0987067accfc3ae84b597e /src/runtime/runtime2.go | |
| parent | 6412750f32224f6820f781d09b2092c5c358dddc (diff) | |
| download | go-0c0e8f224d5724e317952f77d215a752a3a7b7d9.tar.gz go-0c0e8f224d5724e317952f77d215a752a3a7b7d9.zip | |
runtime: don't send preemption signal if there is a signal pending
If multiple threads call preemptone to preempt the same M, it may
send many signals to the same M such that it hardly make
progress, causing live-lock problem. Only send a signal if there
isn't already one pending.
Fixes #37741.
Change-Id: Id94adb0b95acbd18b23abe637a8dcd81ab41b452
Reviewed-on: https://go-review.googlesource.com/c/go/+/223737
Run-TryBot: Cherry Zhang <cherryyz@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime/runtime2.go')
| -rw-r--r-- | src/runtime/runtime2.go | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index 9e3ccb2e40..1a98927647 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -539,6 +539,10 @@ type m struct { // requested, but fails. Accessed atomically. preemptGen uint32 + // Whether this is a pending preemption signal on this M. + // Accessed atomically. + signalPending uint32 + dlogPerM mOS |