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| author | Ming Lei <ming.lei@redhat.com> | 2018-04-08 17:48:08 +0800 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2018-04-10 08:38:46 -0600 |
| commit | bffa9909a6b48d8ca3398dec601bc9162a4020c4 (patch) | |
| tree | 3740c4356291dd9a361ff7647a7c4543779632d3 /block/blk-mq-cpumap.c | |
| parent | a1c735fb790745f94a359df45c11df4a69760389 (diff) | |
| download | lwn-bffa9909a6b48d8ca3398dec601bc9162a4020c4.tar.gz lwn-bffa9909a6b48d8ca3398dec601bc9162a4020c4.zip | |
blk-mq: don't keep offline CPUs mapped to hctx 0
From commit 4b855ad37194 ("blk-mq: Create hctx for each present CPU),
blk-mq doesn't remap queue after CPU topo is changed, that said when
some of these offline CPUs become online, they are still mapped to
hctx 0, then hctx 0 may become the bottleneck of IO dispatch and
completion.
This patch sets up the mapping from the beginning, and aligns to
queue mapping for PCI device (blk_mq_pci_map_queues()).
Cc: Stefan Haberland <sth@linux.vnet.ibm.com>
Cc: Keith Busch <keith.busch@intel.com>
Cc: stable@vger.kernel.org
Fixes: 4b855ad37194 ("blk-mq: Create hctx for each present CPU)
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/blk-mq-cpumap.c')
| -rw-r--r-- | block/blk-mq-cpumap.c | 5 |
1 files changed, 0 insertions, 5 deletions
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index 9f8cffc8a701..3eb169f15842 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -16,11 +16,6 @@ static int cpu_to_queue_index(unsigned int nr_queues, const int cpu) { - /* - * Non present CPU will be mapped to queue index 0. - */ - if (!cpu_present(cpu)) - return 0; return cpu % nr_queues; } |