Commit 576e85c5 authored Oct 19, 2020 by Xianting Tian Committed by Jens Axboe Oct 20, 2020

blk-mq: remove the calling of local_memory_node()



We don't need to check whether the node is memoryless numa node before
calling allocator interface. SLUB(and SLAB,SLOB) relies on the page
allocator to pick a node. Page allocator should deal with memoryless
nodes just fine. It has zonelists constructed for each possible nodes.
And it will automatically fall back into a node which is closest to the
requested node. As long as __GFP_THISNODE is not enforced of course.

The code comments of kmem_cache_alloc_node() of SLAB also showed this:
 * Fallback to other node is possible if __GFP_THISNODE is not set.

blk-mq code doesn't set __GFP_THISNODE, so we can remove the calling
of local_memory_node().

Signed-off-by: Xianting Tian <tian.xianting@h3c.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 0669d2b2

block/blk-mq-cpumap.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -89,7 +89,7 @@ int blk_mq_hw_queue_to_node(struct blk_mq_queue_map *qmap, unsigned int index)

		for_each_possible_cpu(i) {
		if (index == qmap->mq_map[i])
		return local_memory_node(cpu_to_node(i));
		return cpu_to_node(i);
		}

		return NUMA_NO_NODE;

block/blk-mq.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2744,7 +2744,7 @@ static void blk_mq_init_cpu_queues(struct request_queue *q,
		for (j = 0; j < set->nr_maps; j++) {
		hctx = blk_mq_map_queue_type(q, j, i);
		if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
		hctx->numa_node = local_memory_node(cpu_to_node(i));
		hctx->numa_node = cpu_to_node(i);
		}
		}
		}

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