Commit 0d6c356d authored by Isaac J. Manjarres's avatar Isaac J. Manjarres Committed by Andrew Morton
Browse files

mm/mm_init: fix hash table order logging in alloc_large_system_hash() 

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)

Link: https://lkml.kernel.org/r/20251028191020.413002-1-isaacmanjarres@google.com


Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarIsaac J. Manjarres <isaacmanjarres@google.com>
Reviewed-by: default avatarMike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent fa04f5b6

mm/mm_init.c

+1 −1
Original line number Diff line number Diff line
@@ -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,

		virt ? (huge ? "vmalloc hugepage" : "vmalloc") : "linear");



	if (_hash_shift)