blk-mq: allow software queue to map to multiple hardware queues
The mapping used to be dependent on just the CPU location, but
now it's a tuple of (type, cpu) instead. This is a prep patch
for allowing a single software queue to map to multiple hardware
queues. No functional changes in this patch.
This changes the software queue count to an unsigned short
to save a bit of space. We can still support 64K-1 CPUs,
which should be enough. Add a check to catch a wrap.
Reviewed-by: Hannes Reinecke <[email protected]>
Reviewed-by: Keith Busch <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 6a8f8b6..1821f44 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -17,7 +17,7 @@ struct blk_mq_ctx {
} ____cacheline_aligned_in_smp;
unsigned int cpu;
- unsigned int index_hw;
+ unsigned short index_hw[HCTX_MAX_TYPES];
/* incremented at dispatch time */
unsigned long rq_dispatched[2];
