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| author | Cherry Mui <cherryyz@google.com> | 2024-07-03 14:14:34 -0400 |
|---|---|---|
| committer | Cherry Mui <cherryyz@google.com> | 2024-07-03 22:43:11 +0000 |
| commit | 82c14346d89ec0eeca114f9ca0e88516b2cda454 (patch) | |
| tree | 17269064edfa1203db636c1937864841991315f7 /src/runtime/pprof/pprof.go | |
| parent | 7d19d508a994be9731e27b14b6ecc13ccf527138 (diff) | |
| download | go-82c14346d89ec0eeca114f9ca0e88516b2cda454.tar.xz | |
cmd/link: don't disable memory profiling when pprof.WriteHeapProfile is used
We have an optimization that if the memory profile is not consumed
anywhere, we set the memory profiling rate to 0 to disable the
"background" low-rate profiling. We detect whether the memory
profile is used by checking whether the runtime.MemProfile function
is reachable at link time. Previously, all APIs that access the
memory profile go through runtime.MemProfile. But the code was
refactored in CL 572396, and now the legacy entry point
WriteHeapProfile uses pprof_memProfileInternal without going
through runtime.MemProfile. In fact, even with the recommended
runtime/pprof.Profile API (pprof.Lookup or pprof.Profiles),
runtime.MemProfile is only (happen to be) reachable through
countHeap.
Change the linker to check runtime.memProfileInternal instead,
which is on all code paths that retrieve the memory profile. Add
a test case for WriteHeapProfile, so we cover all entry points.
Fixes #68136.
Change-Id: I075c8d45c95c81825a1822f032e23107aea4303c
Reviewed-on: https://go-review.googlesource.com/c/go/+/596538
Reviewed-by: Than McIntosh <thanm@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Diffstat (limited to 'src/runtime/pprof/pprof.go')
| -rw-r--r-- | src/runtime/pprof/pprof.go | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/src/runtime/pprof/pprof.go b/src/runtime/pprof/pprof.go index be17e59875..d3af5bba91 100644 --- a/src/runtime/pprof/pprof.go +++ b/src/runtime/pprof/pprof.go @@ -586,7 +586,8 @@ func writeHeapInternal(w io.Writer, debug int, defaultSampleType string) error { runtime.ReadMemStats(memStats) } - // Find out how many records there are (MemProfile(nil, true)), + // Find out how many records there are (the call + // pprof_memProfileInternal(nil, true) below), // allocate that many records, and get the data. // There's a race—more records might be added between // the two calls—so allocate a few extra records for safety |