[PATCH] blk-mq-debugfs: add mapping show for hw queue to cpu

[weiping zhang <zhangweiping@didichuxing.com>]

A mapping show as following:

hctx		cpus
hctx0		  0   1
hctx1		  2
hctx2		  3
hctx3		  4   5

Signed-off-by: weiping zhang <zhangweiping@didichuxing.com>
---
 block/blk-mq-debugfs.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c
index 9ebc294..a311d5a 100644
--- a/block/blk-mq-debugfs.c
+++ b/block/blk-mq-debugfs.c
@@ -175,6 +175,23 @@ static int queue_poll_stat_show(void *data, struct seq_file *m)
 	return 0;
 }
 
+static int queue_mapping_show(void *data, struct seq_file *m)
+{
+       struct request_queue *q = data;
+       struct blk_mq_hw_ctx *hctx;
+       struct blk_mq_ctx *ctx;
+       int i, j;
+
+       seq_puts(m, "hctx\t\tcpus\n");
+       queue_for_each_hw_ctx(q, hctx, i) {
+               seq_printf(m, "hctx%u\t\t", hctx->queue_num);
+               hctx_for_each_ctx(hctx, ctx, j)
+                       seq_printf(m, "%3u ", ctx->cpu);
+               seq_puts(m, "\n");
+       }
+       return 0;
+}
+
 #define HCTX_STATE_NAME(name) [BLK_MQ_S_##name] = #name
 static const char *const hctx_state_name[] = {
 	HCTX_STATE_NAME(STOPPED),
@@ -754,6 +771,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_queue_attrs[] = {
 	{"requeue_list", 0400, .seq_ops = &queue_requeue_list_seq_ops},
 	{"state", 0600, queue_state_show, queue_state_write},
 	{"write_hints", 0600, queue_write_hint_show, queue_write_hint_store},
+	{"mapping", 0400, queue_mapping_show},
 	{},
 };
 
-- 
2.9.4