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authorIan Lance Taylor <iant@golang.org>2020-04-15 15:39:53 -0700
committerIan Lance Taylor <iant@golang.org>2020-04-17 00:45:52 +0000
commit7ea40f6594ada6631b3fd153c87916c51628a7e2 (patch)
tree2bd5c3a360ed372d90504cfb38d37d806c629fa4 /src/runtime
parent415da71c5d2b02beab9067af4c2ff435de15bb9b (diff)
downloadgo-7ea40f6594ada6631b3fd153c87916c51628a7e2.tar.xz
runtime: use mcache0 if no P in profilealloc
A case that I missed in CL 205239: profilealloc can be called at program startup if GOMAXPROCS is large enough. Fixes #38474 Change-Id: I2f089fc6ec00c376680e1c0b8a2557b62789dd7f Reviewed-on: https://go-review.googlesource.com/c/go/+/228420 Run-TryBot: Ian Lance Taylor <iant@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Michael Pratt <mpratt@google.com>
Diffstat (limited to 'src/runtime')
-rw-r--r--src/runtime/malloc.go11
-rw-r--r--src/runtime/proc_test.go13
2 files changed, 23 insertions, 1 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go
index 5a0d85f645..e1ec5e6496 100644
--- a/src/runtime/malloc.go
+++ b/src/runtime/malloc.go
@@ -1207,7 +1207,16 @@ func reflect_unsafe_NewArray(typ *_type, n int) unsafe.Pointer {
}
func profilealloc(mp *m, x unsafe.Pointer, size uintptr) {
- mp.p.ptr().mcache.next_sample = nextSample()
+ var c *mcache
+ if mp.p != 0 {
+ c = mp.p.ptr().mcache
+ } else {
+ c = mcache0
+ if c == nil {
+ throw("profilealloc called with no P")
+ }
+ }
+ c.next_sample = nextSample()
mProf_Malloc(x, size)
}
diff --git a/src/runtime/proc_test.go b/src/runtime/proc_test.go
index 81bcb98aeb..27dba95eff 100644
--- a/src/runtime/proc_test.go
+++ b/src/runtime/proc_test.go
@@ -1037,3 +1037,16 @@ loop:
t.Errorf("netpollBreak did not interrupt netpoll: slept for: %v", dur)
}
}
+
+// TestBigGOMAXPROCS tests that setting GOMAXPROCS to a large value
+// doesn't cause a crash at startup. See issue 38474.
+func TestBigGOMAXPROCS(t *testing.T) {
+ t.Parallel()
+ output := runTestProg(t, "testprog", "NonexistentTest", "GOMAXPROCS=1024")
+ if strings.Contains(output, "failed to create new OS thread") {
+ t.Skipf("failed to create 1024 threads")
+ }
+ if !strings.Contains(output, "unknown function: NonexistentTest") {
+ t.Errorf("output:\n%s\nwanted:\nunknown function: NonexistentTest", output)
+ }
+}