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| author | Michael Anthony Knyszek <mknyszek@google.com> | 2025-10-17 20:02:55 +0000 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-10-20 20:28:55 -0700 |
| commit | 79ae97fe9bf44814f7bed7e6a6297150070817f3 (patch) | |
| tree | 85a8b3392a3958db55dc733aaac1e5d0f1b1503e /src/runtime | |
| parent | f838faffe21afd2d5c177c04df8836c93e273b4b (diff) | |
| download | go-79ae97fe9bf44814f7bed7e6a6297150070817f3.tar.xz | |
runtime: make procyieldAsm no longer loop infinitely if passed 0
Change-Id: I9f01692373623687e09bee54efebaac0ee361f81
Reviewed-on: https://go-review.googlesource.com/c/go/+/712664
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/asm_386.s | 3 | ||||
| -rw-r--r-- | src/runtime/asm_amd64.s | 3 | ||||
| -rw-r--r-- | src/runtime/asm_arm64.s | 2 | ||||
| -rw-r--r-- | src/runtime/asm_ppc64x.s | 3 | ||||
| -rw-r--r-- | src/runtime/stubs.go | 7 |
5 files changed, 11 insertions, 7 deletions
diff --git a/src/runtime/asm_386.s b/src/runtime/asm_386.s index a54ca110e5..03f1a46b55 100644 --- a/src/runtime/asm_386.s +++ b/src/runtime/asm_386.s @@ -599,10 +599,13 @@ CALLFN(·call1073741824, 1073741824) TEXT runtime·procyieldAsm(SB),NOSPLIT,$0-0 MOVL cycles+0(FP), AX + TESTL AX, AX + JZ done again: PAUSE SUBL $1, AX JNZ again +done: RET TEXT ·publicationBarrier(SB),NOSPLIT,$0-0 diff --git a/src/runtime/asm_amd64.s b/src/runtime/asm_amd64.s index dbf54487a7..a4c6c53a90 100644 --- a/src/runtime/asm_amd64.s +++ b/src/runtime/asm_amd64.s @@ -817,10 +817,13 @@ CALLFN(·call1073741824, 1073741824) TEXT runtime·procyieldAsm(SB),NOSPLIT,$0-0 MOVL cycles+0(FP), AX + TESTL AX, AX + JZ done again: PAUSE SUBL $1, AX JNZ again +done: RET diff --git a/src/runtime/asm_arm64.s b/src/runtime/asm_arm64.s index 94a5b9ee6c..8bbb6b8a87 100644 --- a/src/runtime/asm_arm64.s +++ b/src/runtime/asm_arm64.s @@ -1038,10 +1038,12 @@ aesloop: TEXT runtime·procyieldAsm(SB),NOSPLIT,$0-0 MOVWU cycles+0(FP), R0 + CBZ R0, done again: YIELD SUBW $1, R0 CBNZ R0, again +done: RET // Save state of caller into g->sched, diff --git a/src/runtime/asm_ppc64x.s b/src/runtime/asm_ppc64x.s index e461764e55..aaa2e4346c 100644 --- a/src/runtime/asm_ppc64x.s +++ b/src/runtime/asm_ppc64x.s @@ -614,6 +614,8 @@ CALLFN(·call1073741824, 1073741824) TEXT runtime·procyieldAsm(SB),NOSPLIT|NOFRAME,$0-4 MOVW cycles+0(FP), R7 + CMP $0, R7 + BEQ done // POWER does not have a pause/yield instruction equivalent. // Instead, we can lower the program priority by setting the // Program Priority Register prior to the wait loop and set it @@ -625,6 +627,7 @@ again: CMP $0, R7 BNE again OR R6, R6, R6 // Set PPR priority back to medium-low +done: RET // Save state of caller into g->sched, diff --git a/src/runtime/stubs.go b/src/runtime/stubs.go index 1692283541..d5a35d15b2 100644 --- a/src/runtime/stubs.go +++ b/src/runtime/stubs.go @@ -283,13 +283,6 @@ func procyield(cycles uint32) { } // procyieldAsm is the assembly implementation of procyield. -// -// It may loop infinitely if called with cycles == 0. Prefer -// procyield, which will compile down to nothing in such cases, -// instead. -// -// FIXME: The implementation really should not loop infinitely if -// the number of cycles is 0. func procyieldAsm(cycles uint32) type neverCallThisFunction struct{} |