Commit 43ca5bc4 authored May 08, 2017 by Michal Hocko Committed by Linus Torvalds May 08, 2017

lib/rhashtable.c: simplify a strange allocation pattern

alloc_bucket_locks allocation pattern is quite unusual.  We are
preferring vmalloc when CONFIG_NUMA is enabled.  The rationale is that
vmalloc will respect the memory policy of the current process and so the
backing memory will get distributed over multiple nodes if the requester
is configured properly.  At least that is the intention, in reality
rhastable is shrunk and expanded from a kernel worker so no mempolicy
can be assumed.

Let's just simplify the code and use kvmalloc helper, which is a
transparent way to use kmalloc with vmalloc fallback, if the caller is
allowed to block and use the flag otherwise.

Link: http://lkml.kernel.org/r/20170306103032.2540-4-mhocko@kernel.org


Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Tom Herbert <tom@herbertland.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 6c5ab651

lib/rhashtable.c

+3 −10

Original line number	Original line	Diff line number	Diff line
	@@ -86,16 +86,9 @@ static int alloc_bucket_locks(struct rhashtable ht, struct bucket_table tbl,
	size = min(size, 1U << tbl->nest);		size = min(size, 1U << tbl->nest);

	if (sizeof(spinlock_t) != 0) {		if (sizeof(spinlock_t) != 0) {
	tbl->locks = NULL;		if (gfpflags_allow_blocking(gfp))
	#ifdef CONFIG_NUMA		tbl->locks = kvmalloc(size * sizeof(spinlock_t), gfp);
	if (size * sizeof(spinlock_t) > PAGE_SIZE &&		else
	gfp == GFP_KERNEL)
	tbl->locks = vmalloc(size * sizeof(spinlock_t));
	#endif
	if (gfp != GFP_KERNEL)
	gfp \|= __GFP_NOWARN \| __GFP_NORETRY;

	if (!tbl->locks)
	tbl->locks = kmalloc_array(size, sizeof(spinlock_t),		tbl->locks = kmalloc_array(size, sizeof(spinlock_t),
	gfp);		gfp);
	if (!tbl->locks)		if (!tbl->locks)

Admin message