diff options
| author | Michael Anthony Knyszek <mknyszek@google.com> | 2024-08-27 21:02:02 +0000 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2025-02-03 08:21:09 -0800 |
| commit | b25b5f3ff4e671aa4f5897c788137fe91f62cf57 (patch) | |
| tree | ef37f5db04b45dad5303ba33911a9ff133348705 /src/runtime/mgcmark.go | |
| parent | 4f11d5879a01e64cb8bd59911bb205ffedd4f265 (diff) | |
| download | go-b25b5f3ff4e671aa4f5897c788137fe91f62cf57.tar.xz | |
runtime: fix GODEBUG=gccheckmark=1 and add smoke test
This change fixes GODEBUG=gccheckmark=1 which seems to have bit-rotted.
Because the root jobs weren't being reset, it wasn't doing anything.
Then, it turned out that checkmark mode would queue up noscan objects in
workbufs, which caused it to fail. Then it turned out checkmark mode was
broken with user arenas, since their heap arenas are not registered
anywhere. Then, it turned out that checkmark mode could just not run
properly if the goroutine's preemption flag was set (since
sched.gcwaiting is true during the STW). And lastly, it turned out that
async preemption could cause erroneous checkmark failures.
This change fixes all these issues and adds a simple smoke test to dist
to run the runtime tests under gccheckmark, which exercises all of these
issues.
Fixes #69074.
Fixes #69377.
Fixes #69376.
Change-Id: Iaa0bb7b9e63ed4ba34d222b47510d6292ce168bc
Cq-Include-Trybots: luci.golang.try:gotip-linux-amd64-longtest
Reviewed-on: https://go-review.googlesource.com/c/go/+/608915
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Diffstat (limited to 'src/runtime/mgcmark.go')
| -rw-r--r-- | src/runtime/mgcmark.go | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/src/runtime/mgcmark.go b/src/runtime/mgcmark.go index 823b2bd7df..92ef215ee0 100644 --- a/src/runtime/mgcmark.go +++ b/src/runtime/mgcmark.go @@ -89,9 +89,9 @@ func gcMarkRootPrepare() { // // Break up the work into arenas, and further into chunks. // - // Snapshot allArenas as markArenas. This snapshot is safe because allArenas + // Snapshot heapArenas as markArenas. This snapshot is safe because heapArenas // is append-only. - mheap_.markArenas = mheap_.allArenas[:len(mheap_.allArenas):len(mheap_.allArenas)] + mheap_.markArenas = mheap_.heapArenas[:len(mheap_.heapArenas):len(mheap_.heapArenas)] work.nSpanRoots = len(mheap_.markArenas) * (pagesPerArena / pagesPerSpanRoot) // Scan stacks. @@ -1614,13 +1614,13 @@ func greyobject(obj, base, off uintptr, span *mspan, gcw *gcWork, objIndex uintp if arena.pageMarks[pageIdx]&pageMask == 0 { atomic.Or8(&arena.pageMarks[pageIdx], pageMask) } + } - // If this is a noscan object, fast-track it to black - // instead of greying it. - if span.spanclass.noscan() { - gcw.bytesMarked += uint64(span.elemsize) - return - } + // If this is a noscan object, fast-track it to black + // instead of greying it. + if span.spanclass.noscan() { + gcw.bytesMarked += uint64(span.elemsize) + return } // We're adding obj to P's local workbuf, so it's likely |