| Message ID | 20250123-fix-blk_mq_map_hw_queues-v1-1-08dbd01f2c39@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | blk-mq: create correct map for fallback case | expand |
On Thu, 23 Jan 2025 14:08:29 +0100, Daniel Wagner wrote: > 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. > > [...] Applied, thanks! [1/1] blk-mq: create correct map for fallback case commit: a9ae6fe1c319c4776c2b11e85e15109cd3f04076 Best regards,
On Thu, 23 Jan 2025 14:08:29 +0100 Daniel Wagner <wagi@kernel.org> wrote: > 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> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> -- Steve > Closes: https://lore.kernel.org/all/20250122093020.6e8a4e5b@gandalf.local.home/ > Signed-off-by: Daniel Wagner <wagi@kernel.org> > --- > block/blk-mq-cpumap.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) >
diff --git a/block/blk-mq-cpumap.c b/block/blk-mq-cpumap.c index ad8d6a363f24ae11968b42f7bcfd6a719a0499b7..444798c5374f48088b661b519f2638bda8556cf2 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);
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> --- block/blk-mq-cpumap.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- base-commit: c4b9570cfb63501638db720f3bee9f6dfd044b82 change-id: 20250123-fix-blk_mq_map_hw_queues-dc72a6a1c71a Best regards,