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 <loberman@xxxxxxxxxx>
Cc: Ewan Milne <emilne@xxxxxxxxxx>
Cc: Stefan Haberland <sth@xxxxxxxxxxxxxxxxxx>
Cc: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Sagi Grimberg <sagi@xxxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
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);
--
2.9.5
