On Wed, 2018-04-25 at 04:01 +0800, Ming Lei wrote: > This reverts commit 37c7c6c76d431dd7ef9c29d95f6052bd425f004c. > > Turns out some drivers(most are FC drivers) may not use managed > IRQ affinity, and has their customized .map_queues meantime, so > still keep this code for avoiding regression. > > Reported-by: Laurence Oberman <lober...@redhat.com> > Cc: Ewan Milne <emi...@redhat.com> > Cc: Stefan Haberland <s...@linux.vnet.ibm.com> > Cc: Christian Borntraeger <borntrae...@de.ibm.com> > Cc: Christoph Hellwig <h...@lst.de> > Cc: Sagi Grimberg <s...@grimberg.me> > Signed-off-by: Ming Lei <ming....@redhat.com> > --- > block/blk-mq.c | 34 +++++++++++++++++++++++++++++++--- > 1 file changed, 31 insertions(+), 3 deletions(-) > > diff --git a/block/blk-mq.c b/block/blk-mq.c > index e39276852638..f4891b792d0d 100644 > --- a/block/blk-mq.c > +++ b/block/blk-mq.c > @@ -2407,7 +2407,7 @@ static void blk_mq_free_map_and_requests(struct > blk_mq_tag_set *set, > > static void blk_mq_map_swqueue(struct request_queue *q) > { > - unsigned int i; > + unsigned int i, hctx_idx; > struct blk_mq_hw_ctx *hctx; > struct blk_mq_ctx *ctx; > struct blk_mq_tag_set *set = q->tag_set; > @@ -2424,8 +2424,23 @@ static void blk_mq_map_swqueue(struct > request_queue *q) > > /* > * Map software to hardware queues. > + * > + * If the cpu isn't present, the cpu is mapped to first > hctx. > */ > for_each_possible_cpu(i) { > + hctx_idx = q->mq_map[i]; > + /* unmapped hw queue can be remapped after CPU topo > changed */ > + if (!set->tags[hctx_idx] && > + !__blk_mq_alloc_rq_map(set, hctx_idx)) { > + /* > + * If tags initialization fail for some > hctx, > + * that hctx won't be brought online. In > this > + * case, remap the current ctx to hctx[0] > which > + * is guaranteed to always have tags > allocated > + */ > + q->mq_map[i] = 0; > + } > + > ctx = per_cpu_ptr(q->queue_ctx, i); > hctx = blk_mq_map_queue(q, i); > > @@ -2437,8 +2452,21 @@ static void blk_mq_map_swqueue(struct > request_queue *q) > mutex_unlock(&q->sysfs_lock); > > queue_for_each_hw_ctx(q, hctx, i) { > - /* every hctx should get mapped by at least one CPU > */ > - WARN_ON(!hctx->nr_ctx); > + /* > + * If no software queues are mapped to this hardware > queue, > + * disable it and free the request entries. > + */ > + if (!hctx->nr_ctx) { > + /* Never unmap queue 0. We need it as a > + * fallback in case of a new remap fails > + * allocation > + */ > + if (i && set->tags[i]) > + blk_mq_free_map_and_requests(set, > i); > + > + hctx->tags = NULL; > + continue; > + } > > hctx->tags = set->tags[i]; > WARN_ON(!hctx->tags);
Hello Ming Thanks for getting this fixed so quickly. The dumpstack is gone now of course. Tested-by: Laurence Oberman <lober...@redhat.com>