For most of ARCHs, 'nr_cpus=1' is passed for kdump kernel, so
nr_hw_queues for each mapping is supposed to be 1 already.
More importantly, this way may cause trouble for driver, because blk-mq and
driver see different queue mapping since driver should setup hardware
queue setting before calling into allocating blk-mq tagset.
So not overriding nr_hw_queues and nr_maps for kdump kernel.
Cc: Wen Xiong <wenxiong@xxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/blk-mq.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 6abb4ce46baa..be5f6380d46d 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -4391,7 +4391,7 @@ static void blk_mq_update_queue_map(struct blk_mq_tag_set *set)
if (set->nr_maps == 1)
set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues;
- if (set->ops->map_queues && !is_kdump_kernel()) {
+ if (set->ops->map_queues) {
int i;
/*
@@ -4490,14 +4490,12 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
/*
* If a crashdump is active, then we are potentially in a very
- * memory constrained environment. Limit us to 1 queue and
- * 64 tags to prevent using too much memory.
+ * memory constrained environment. Limit us to 64 tags to prevent
+ * using too much memory.
*/
- if (is_kdump_kernel()) {
- set->nr_hw_queues = 1;
- set->nr_maps = 1;
+ if (is_kdump_kernel())
set->queue_depth = min(64U, set->queue_depth);
- }
+
/*
* There is no use for more h/w queues than cpus if we just have
* a single map
@@ -4527,7 +4525,7 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
GFP_KERNEL, set->numa_node);
if (!set->map[i].mq_map)
goto out_free_mq_map;
- set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues;
+ set->map[i].nr_queues = set->nr_hw_queues;
}
blk_mq_update_queue_map(set);
--
2.41.0
