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| author | Bart Van Assche <bart.vanassche@sandisk.com> | 2017-06-01 08:55:12 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@fb.com> | 2017-06-01 13:02:59 -0600 |
| commit | 2720bab50258782573df0f536681bece11e784f0 (patch) | |
| tree | 06a2527f7094bc2da1e4fbb681db28743d6fa804 /block/blk-mq-debugfs.c | |
| parent | 8ef1a191038c138d5675933cd69d47747d0d396b (diff) | |
| download | linux-0-day-2720bab50258782573df0f536681bece11e784f0.tar.gz linux-0-day-2720bab50258782573df0f536681bece11e784f0.tar.xz | |
blk-mq-debugfs: Show busy requests
Requests that got stuck in a block driver are neither on
blk_mq_ctx.rq_list nor on any hw dispatch queue. Make these
visible in debugfs through the "busy" attribute.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Eduardo Valentin <eduval@amazon.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq-debugfs.c')
| -rw-r--r-- | block/blk-mq-debugfs.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c index 8b06a12c14618..90c454bbaf925 100644 --- a/block/blk-mq-debugfs.c +++ b/block/blk-mq-debugfs.c @@ -370,6 +370,36 @@ static const struct seq_operations hctx_dispatch_seq_ops = { .show = blk_mq_debugfs_rq_show, }; +struct show_busy_params { + struct seq_file *m; + struct blk_mq_hw_ctx *hctx; +}; + +/* + * Note: the state of a request may change while this function is in progress, + * e.g. due to a concurrent blk_mq_finish_request() call. + */ +static void hctx_show_busy_rq(struct request *rq, void *data, bool reserved) +{ + const struct show_busy_params *params = data; + + if (blk_mq_map_queue(rq->q, rq->mq_ctx->cpu) == params->hctx && + test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) + __blk_mq_debugfs_rq_show(params->m, + list_entry_rq(&rq->queuelist)); +} + +static int hctx_busy_show(void *data, struct seq_file *m) +{ + struct blk_mq_hw_ctx *hctx = data; + struct show_busy_params params = { .m = m, .hctx = hctx }; + + blk_mq_tagset_busy_iter(hctx->queue->tag_set, hctx_show_busy_rq, + ¶ms); + + return 0; +} + static int hctx_ctx_map_show(void *data, struct seq_file *m) { struct blk_mq_hw_ctx *hctx = data; @@ -705,6 +735,7 @@ static const struct blk_mq_debugfs_attr blk_mq_debugfs_hctx_attrs[] = { {"state", 0400, hctx_state_show}, {"flags", 0400, hctx_flags_show}, {"dispatch", 0400, .seq_ops = &hctx_dispatch_seq_ops}, + {"busy", 0400, hctx_busy_show}, {"ctx_map", 0400, hctx_ctx_map_show}, {"tags", 0400, hctx_tags_show}, {"tags_bitmap", 0400, hctx_tags_bitmap_show}, |