On Tue, Oct 28, 2025 at 12:10:12PM -0700, Isaac J. Manjarres wrote:
When emitting the order of the allocation for a hash table, alloc_large_system_hash() unconditionally subtracts PAGE_SHIFT from log base 2 of the allocation size. This is not correct if the allocation size is smaller than a page, and yields a negative value for the order as seen below:
TCP established hash table entries: 32 (order: -4, 256 bytes, linear) TCP bind hash table entries: 32 (order: -2, 1024 bytes, linear)
Use get_order() to compute the order when emitting the hash table information to correctly handle cases where the allocation size is smaller than a page:
TCP established hash table entries: 32 (order: 0, 256 bytes, linear) TCP bind hash table entries: 32 (order: 0, 1024 bytes, linear)
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Isaac J. Manjarres isaacmanjarres@google.com
Reviewed-by: Mike Rapoport (Microsoft) rppt@kernel.org
mm/mm_init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/mm_init.c b/mm/mm_init.c index 3db2dea7db4c..7712d887b696 100644 --- a/mm/mm_init.c +++ b/mm/mm_init.c @@ -2469,7 +2469,7 @@ void *__init alloc_large_system_hash(const char *tablename, panic("Failed to allocate %s hash table\n", tablename); pr_info("%s hash table entries: %ld (order: %d, %lu bytes, %s)\n",
tablename, 1UL << log2qty, ilog2(size) - PAGE_SHIFT, size,
tablename, 1UL << log2qty, get_order(size), size,if (_hash_shift) -- 2.51.1.851.g4ebd6896fd-goog