diff options
| -rw-r--r-- | nptl/allocatestack.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/nptl/allocatestack.c b/nptl/allocatestack.c index 2a5ac22117..e8dfbbb8de 100644 --- a/nptl/allocatestack.c +++ b/nptl/allocatestack.c @@ -656,6 +656,15 @@ allocate_stack (const struct pthread_attr *attr, struct pthread **pdp, return errno; } + /* We've marked this guard region unwritable, but it's + possible it already became resident, the most common case + being transparent hugepages; if stack + guard (+ adjacent + mmap regions) were more than 2MB, the kernel might have + filled in a full hugepage when we touched the thread + descriptor above. This can waste a lot of memory; mark + the guard unused. This shouldn't fail, but if it does, + we can't really do anything about it so ignore it. */ + madvise (guard, guardsize, MADV_DONTNEED); pd->guardsize = guardsize; } |