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| author | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-08-20 13:22:35 -0300 |
|---|---|---|
| committer | Adhemerval Zanella <adhemerval.zanella@linaro.org> | 2021-12-15 17:35:39 -0300 |
| commit | c1beb51d08d3d7ec935b0a2419b4c6fad91d1969 (patch) | |
| tree | 6c5b2faf0fa3044c61e4462ff4ba540d976cbb44 /malloc/malloc.c | |
| parent | 98d5fcb8d099a1a868e032c89891c395a2f365c5 (diff) | |
| download | glibc-c1beb51d08d3d7ec935b0a2419b4c6fad91d1969.tar.gz | |
malloc: Add Huge Page support to arenas
It is enabled as default for glibc.malloc.hugetlb set to 2 or higher.
It also uses a non configurable minimum value and maximum value,
currently set respectively to 1 and 4 selected huge page size.
The arena allocation with huge pages does not use MAP_NORESERVE. As
indicate by kernel internal documentation [1], the flag might trigger
a SIGBUS on soft page faults if at memory access there is no left
pages in the pool.
On systems without a reserved huge pages pool, is just stress the
mmap(MAP_HUGETLB) allocation failure. To improve test coverage it is
required to create a pool with some allocated pages.
Checked on x86_64-linux-gnu with no reserved pages, 10 reserved pages
(which trigger mmap(MAP_HUGETBL) failures) and with 256 reserved pages
(which does not trigger mmap(MAP_HUGETLB) failures).
[1] https://www.kernel.org/doc/html/v4.18/vm/hugetlbfs_reserv.html#resv-map-modifications
Reviewed-by: DJ Delorie <dj@redhat.com>
Diffstat (limited to 'malloc/malloc.c')
| -rw-r--r-- | malloc/malloc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c index 75efdc2ee7..1698d45d1e 100644 --- a/malloc/malloc.c +++ b/malloc/malloc.c @@ -5302,7 +5302,7 @@ static __always_inline int do_set_mmap_threshold (size_t value) { /* Forbid setting the threshold too high. */ - if (value <= HEAP_MAX_SIZE / 2) + if (value <= heap_max_size () / 2) { LIBC_PROBE (memory_mallopt_mmap_threshold, 3, value, mp_.mmap_threshold, mp_.no_dyn_threshold); |