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authorCherry Mui <cherryyz@google.com>2024-07-03 14:14:34 -0400
committerCherry Mui <cherryyz@google.com>2024-07-03 22:43:11 +0000
commit82c14346d89ec0eeca114f9ca0e88516b2cda454 (patch)
tree17269064edfa1203db636c1937864841991315f7 /src/runtime/pprof
parent7d19d508a994be9731e27b14b6ecc13ccf527138 (diff)
downloadgo-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')
-rw-r--r--src/runtime/pprof/pprof.go3
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