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| author | Daniel Wagner <wagi@kernel.org> | 2025-01-23 14:08:29 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2025-01-23 06:34:32 -0700 |
| commit | a9ae6fe1c319c4776c2b11e85e15109cd3f04076 (patch) | |
| tree | b3788b7f5646728dc6ba3ca5af426488ad522895 /block | |
| parent | b13ee668e8280ca5b07f8ce2846b9957a8a10853 (diff) | |
| download | linux-a9ae6fe1c319c4776c2b11e85e15109cd3f04076.tar.gz linux-a9ae6fe1c319c4776c2b11e85e15109cd3f04076.tar.bz2 linux-a9ae6fe1c319c4776c2b11e85e15109cd3f04076.zip | |
blk-mq: create correct map for fallback case
The fallback code in blk_mq_map_hw_queues is original from
blk_mq_pci_map_queues and was added to handle the case where
pci_irq_get_affinity will return NULL for !SMP configuration.
blk_mq_map_hw_queues replaces besides blk_mq_pci_map_queues also
blk_mq_virtio_map_queues which used to use blk_mq_map_queues for the
fallback.
It's possible to use blk_mq_map_queues for both cases though.
blk_mq_map_queues creates the same map as blk_mq_clear_mq_map for !SMP
that is CPU 0 will be mapped to hctx 0.
The WARN_ON_ONCE has to be dropped for virtio as the fallback is also
taken for certain configuration on default. Though there is still a
WARN_ON_ONCE check in lib/group_cpus.c:
WARN_ON(nr_present + nr_others < numgrps);
which will trigger if the caller tries to create more hardware queues
than CPUs. It tests the same as the WARN_ON_ONCE in
blk_mq_pci_map_queues did.
Fixes: a5665c3d150c ("virtio: blk/scsi: replace blk_mq_virtio_map_queues with blk_mq_map_hw_queues")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Closes: https://lore.kernel.org/all/20250122093020.6e8a4e5b@gandalf.local.home/
Signed-off-by: Daniel Wagner <wagi@kernel.org>
Link: https://lore.kernel.org/r/20250123-fix-blk_mq_map_hw_queues-v1-1-08dbd01f2c39@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-mq-cpumap.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index ad8d6a363f24..444798c5374f 100644 --- a/block/blk-mq-cpumap.c +++ b/block/blk-mq-cpumap.c @@ -87,7 +87,6 @@ void blk_mq_map_hw_queues(struct blk_mq_queue_map *qmap, return; fallback: - WARN_ON_ONCE(qmap->nr_queues > 1); - blk_mq_clear_mq_map(qmap); + blk_mq_map_queues(qmap); } EXPORT_SYMBOL_GPL(blk_mq_map_hw_queues); |