From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Bart Van Assche To: "axboe@kernel.dk" CC: "hch@lst.de" , "linux-block@vger.kernel.org" , "hare@suse.com" , "osandov@fb.com" , "ming.lei@redhat.com" Subject: Re: [PATCH 4/5] blk-mq-debugfs: Show busy requests Date: Fri, 26 May 2017 21:22:37 +0000 Message-ID: <1495833756.2634.9.camel@sandisk.com> References: <20170525233810.23211-1-bart.vanassche@sandisk.com> <20170525233810.23211-5-bart.vanassche@sandisk.com> <1495833461.2634.7.camel@sandisk.com> <0c124a6c-8c2d-1fb9-118f-96ce7fadc64c@kernel.dk> In-Reply-To: <0c124a6c-8c2d-1fb9-118f-96ce7fadc64c@kernel.dk> Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 List-ID: On Fri, 2017-05-26 at 15:20 -0600, Jens Axboe wrote: > On 05/26/2017 03:17 PM, Bart Van Assche wrote: > > On Fri, 2017-05-26 at 07:26 -0600, Jens Axboe wrote: > > > On 05/25/2017 05:38 PM, 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. > > > >=20 > > > > Signed-off-by: Bart Van Assche > > > > Cc: Christoph Hellwig > > > > Cc: Hannes Reinecke > > > > Cc: Omar Sandoval > > > > Cc: Ming Lei > > > > --- > > > > block/blk-mq-debugfs.c | 25 +++++++++++++++++++++++++ > > > > 1 file changed, 25 insertions(+) > > > >=20 > > > > diff --git a/block/blk-mq-debugfs.c b/block/blk-mq-debugfs.c > > > > index 8b06a12c1461..70a2b955afee 100644 > > > > --- a/block/blk-mq-debugfs.c > > > > +++ b/block/blk-mq-debugfs.c > > > > @@ -370,6 +370,30 @@ static const struct seq_operations hctx_dispat= ch_seq_ops =3D { > > > > .show =3D blk_mq_debugfs_rq_show, > > > > }; > > > > =20 > > > > +struct show_busy_ctx { > > > > + struct seq_file *m; > > > > + struct blk_mq_hw_ctx *hctx; > > > > +}; > > > > + > > > > +static void hctx_show_busy(struct request *rq, void *data, bool re= served) > > > > +{ > > > > + const struct show_busy_ctx *ctx =3D data; > > >=20 > > > Let's not call that variable 'ctx', in blk-mq that's pretty much > > > reserved for the sw queues. > >=20 > > Hello Jens, > >=20 > > How about renaming show_busy_ctx into show_busy_params and ctx into par= ams? >=20 > I think that would be an improvement. Also, this: >=20 > blk_mq_debugfs_rq_show(ctx->m, &rq->queuelist); >=20 > doesn't look safe at all, as you are passing in a node instead of a > head. I think you just want to use __blk_mq_debugfs_rq_show() here. Hello Jens, That change will make the compiler perform type checking. I agree that's an improvement. I will make that change. Bart.=