Revert "runtime: preempt more aggressively when panicking"
This reverts CL 546135.
Reason for revert: Causes occasional throw during panic
For #65416.
Change-Id: I78c15637da18f85ede785363b777aa7d1dead3c3
Reviewed-on: https://go-review.googlesource.com/c/go/+/560455
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: Bryan Mills <bcmills@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
diff --git a/src/runtime/preempt.go b/src/runtime/preempt.go
index aedf7f3..82d85cd 100644
--- a/src/runtime/preempt.go
+++ b/src/runtime/preempt.go
@@ -359,11 +359,7 @@
// In some cases the PC is safe for asynchronous preemption but it
// also needs to adjust the resumption PC. The new PC is returned in
// the second result.
-//
-// If noResume is true, we know we're not going to resume execution
-// on this goroutine (as we're crashing), and thus we can preempt
-// more aggressively.
-func isAsyncSafePoint(gp *g, pc, sp, lr uintptr, noResume bool) (bool, uintptr) {
+func isAsyncSafePoint(gp *g, pc, sp, lr uintptr) (bool, uintptr) {
mp := gp.m
// Only user Gs can have safe-points. We check this first
@@ -374,7 +370,7 @@
}
// Check M state.
- if mp.p == 0 || (!canPreemptM(mp) && !noResume) {
+ if mp.p == 0 || !canPreemptM(mp) {
return false, 0
}
@@ -389,13 +385,6 @@
// Not Go code.
return false, 0
}
- if noResume && f.flag&abi.FuncFlagAsm == 0 {
- // We're not going to resume execution and not going to scan the
- // stack for GC, so we don't care whether it is a safe point, and
- // also don't care the resumption PC.
- // TODO: maybe we can preempt non-SPWRITE assembly functions?
- return true, pc
- }
if (GOARCH == "mips" || GOARCH == "mipsle" || GOARCH == "mips64" || GOARCH == "mips64le") && lr == pc+8 && funcspdelta(f, pc) == 0 {
// We probably stopped at a half-executed CALL instruction,
// where the LR is updated but the PC has not. If we preempt
