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| author | Ian Lance Taylor <iant@golang.org> | 2024-02-14 17:54:00 -0800 |
|---|---|---|
| committer | Michael Pratt <mpratt@google.com> | 2025-04-22 02:49:42 -0700 |
| commit | 352dd2d932c1c1c6dbc3e112fcdfface07d4fffb (patch) | |
| tree | 587e2fc3f0a2134a91844f121c21ce9d0aff2ef5 | |
| parent | 336626bac4c62b617127d41dccae17eed0350b0f (diff) | |
| download | go-352dd2d932c1c1c6dbc3e112fcdfface07d4fffb.tar.xz | |
runtime: only poll network from one P at a time in findRunnable
For #65064
Change-Id: Ifecd7e332d2cf251750752743befeda4ed396f33
Reviewed-on: https://go-review.googlesource.com/c/go/+/564197
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Artur M. Wolff <artur.m.wolff@gmail.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Reviewed-by: Mauri de Souza Meneguzzo <mauri870@gmail.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
| -rw-r--r-- | src/runtime/proc.go | 8 | ||||
| -rw-r--r-- | src/runtime/runtime2.go | 7 |
2 files changed, 10 insertions, 5 deletions
diff --git a/src/runtime/proc.go b/src/runtime/proc.go index db7a5b2bb1..44c6d0b4e4 100644 --- a/src/runtime/proc.go +++ b/src/runtime/proc.go @@ -3387,8 +3387,12 @@ top: // blocked thread (e.g. it has already returned from netpoll, but does // not set lastpoll yet), this thread will do blocking netpoll below // anyway. - if netpollinited() && netpollAnyWaiters() && sched.lastpoll.Load() != 0 { - if list, delta := netpoll(0); !list.empty() { // non-blocking + // We only poll from one thread at a time to avoid kernel contention + // on machines with many cores. + if netpollinited() && netpollAnyWaiters() && sched.lastpoll.Load() != 0 && sched.pollingNet.Swap(1) == 0 { + list, delta := netpoll(0) + sched.pollingNet.Store(0) + if !list.empty() { // non-blocking gp := list.pop() injectglist(&list) netpollAdjustWaiters(delta) diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go index e56b45053e..27d14b890b 100644 --- a/src/runtime/runtime2.go +++ b/src/runtime/runtime2.go @@ -757,9 +757,10 @@ type p struct { } type schedt struct { - goidgen atomic.Uint64 - lastpoll atomic.Int64 // time of last network poll, 0 if currently polling - pollUntil atomic.Int64 // time to which current poll is sleeping + goidgen atomic.Uint64 + lastpoll atomic.Int64 // time of last network poll, 0 if currently polling + pollUntil atomic.Int64 // time to which current poll is sleeping + pollingNet atomic.Int32 // 1 if some P doing non-blocking network poll lock mutex |