From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Thu, 1 Jun 2017 10:47:15 +0800 From: Ming Lei To: Bart Van Assche Cc: Jens Axboe , linux-block@vger.kernel.org, Christoph Hellwig , Hannes Reinecke , Omar Sandoval Subject: Re: [PATCH v2 3/4] blk-mq-debugfs: Show busy requests Message-ID: <20170601024714.GE23563@ming.t460p> References: <20170531213050.30276-1-bart.vanassche@sandisk.com> <20170531213050.30276-4-bart.vanassche@sandisk.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20170531213050.30276-4-bart.vanassche@sandisk.com> List-ID: On Wed, May 31, 2017 at 02:30:49PM -0700, Bart Van Assche wrote: > 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 > Cc: Christoph Hellwig > Cc: Hannes Reinecke > Cc: Omar Sandoval > Cc: Ming Lei > --- > block/blk-mq-debugfs.c | 26 ++++++++++++++++++++++++++ > 1 file changed, 26 insertions(+) > > diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c > index 8b06a12c1461..fa0f624dfccd 100644 > --- a/block/blk-mq-debugfs.c > +++ b/block/blk-mq-debugfs.c > @@ -370,6 +370,31 @@ 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; > +}; > + > +static void hctx_show_busy(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)); > +} Not like dumping requests in ctx and requeue list, the dumped requests here may have been released and the result may not be 100% reliable, so suggest to add comment for this fact. Otherwise, looks fine for me. Thanks, Ming