On 6/19/24 05:34, Ming Lei wrote:
IO logical block size is one fundamental queue limit, and every IO has
to be aligned with logical block size because our bio split can't deal
with unaligned bio.
The check has to be done with queue usage counter grabbed because device
reconfiguration may change logical block size, and we can prevent the
reconfiguration from happening by holding queue usage counter.
logical_block_size stays in the 1st cache line of queue_limits, and this
cache line is always fetched in fast path via bio_may_exceed_limits(),
so IO perf won't be affected by this check.
Cc: Yi Zhang <yi.zhang@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Cc: Ye Bin <yebin10@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
Is this still an issue after the atomic queue limits patchset from
Christoph?
One of the changes there is that we now always freeze the queue before
changing any limits.
So really this check should never trigger.
Hmm?
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg
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