runtime: convert schedt.pollUntil to atomic type

Note that this converts pollUntil from uint64 to int64, the type used by
nanotime().

For #53821.

Change-Id: Iec9ec7e09d3350552561d0708ba6ea9e8a8ae7ab
Reviewed-on: https://go-review.googlesource.com/c/go/+/419443
Run-TryBot: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/runtime/align_runtime_test.go b/src/runtime/align_runtime_test.go
index c3b9c1712ca72e23654b63ac4c10fb484bcde295..e7af4cd6ff277338369171826af78cc763b4d5b5 100644 (file)
--- a/src/runtime/align_runtime_test.go
+++ b/src/runtime/align_runtime_test.go
@@ -17,7 +17,6 @@ var AtomicFields = []uintptr{
        unsafe.Offsetof(p{}.timer0When),
        unsafe.Offsetof(p{}.timerModifiedEarliest),
        unsafe.Offsetof(p{}.gcFractionalMarkTime),
-       unsafe.Offsetof(schedt{}.pollUntil),
        unsafe.Offsetof(schedt{}.timeToRun),
        unsafe.Offsetof(timeHistogram{}.underflow),
        unsafe.Offsetof(profBuf{}.overflow),

diff --git a/src/runtime/proc.go b/src/runtime/proc.go
index fd9c1daf433e441c094cf4b54693a24d9ac4a490..07c7b1b7c1539f25c9d9a6318d6c1faaf1e9821d 100644 (file)
--- a/src/runtime/proc.go
+++ b/src/runtime/proc.go
@@ -2804,7 +2804,7 @@ top:
 
        // Poll network until next timer.
        if netpollinited() && (atomic.Load(&netpollWaiters) > 0 || pollUntil != 0) && sched.lastpoll.Swap(0) != 0 {
-               atomic.Store64(&sched.pollUntil, uint64(pollUntil))
+               sched.pollUntil.Store(pollUntil)
                if mp.p != 0 {
                        throw("findrunnable: netpoll with p")
                }
@@ -2825,7 +2825,7 @@ top:
                        delay = 0
                }
                list := netpoll(delay) // block until new work is available
-               atomic.Store64(&sched.pollUntil, 0)
+               sched.pollUntil.Store(0)
                sched.lastpoll.Store(now)
                if faketime != 0 && list.empty() {
                        // Using fake time and nothing is ready; stop M.
@@ -2856,7 +2856,7 @@ top:
                        goto top
                }
        } else if pollUntil != 0 && netpollinited() {
-               pollerPollUntil := int64(atomic.Load64(&sched.pollUntil))
+               pollerPollUntil := sched.pollUntil.Load()
                if pollerPollUntil == 0 || pollerPollUntil > pollUntil {
                        netpollBreak()
                }
@@ -3071,7 +3071,7 @@ func wakeNetPoller(when int64) {
                // field is either zero or the time to which the current
                // poll is expected to run. This can have a spurious wakeup
                // but should never miss a wakeup.
-               pollerPollUntil := int64(atomic.Load64(&sched.pollUntil))
+               pollerPollUntil := sched.pollUntil.Load()
                if pollerPollUntil == 0 || pollerPollUntil > when {
                        netpollBreak()
                }

diff --git a/src/runtime/runtime2.go b/src/runtime/runtime2.go
index 1d678883f0edda7b9dbf530aa451a9b717f6d84b..17d47c07263aaa47d28185bbe5e21b61f70790d3 100644 (file)
--- a/src/runtime/runtime2.go
+++ b/src/runtime/runtime2.go
@@ -758,10 +758,9 @@ type p struct {
 }
 
 type schedt struct {
-       // accessed atomically. keep at top to ensure alignment on 32-bit systems.
        goidgen   atomic.Uint64
        lastpoll  atomic.Int64 // time of last network poll, 0 if currently polling
-       pollUntil uint64 // time to which current poll is sleeping
+       pollUntil atomic.Int64 // time to which current poll is sleeping
 
        lock mutex