From: Doug Anderson <dianders@chromium.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
Paolo Valente <paolo.valente@linaro.org>,
Salman Qazi <sqazi@google.com>,
linux-block <linux-block@vger.kernel.org>,
linux-scsi@vger.kernel.org, Guenter Roeck <groeck@chromium.org>,
Ajay Joshi <ajay.joshi@wdc.com>, Arnd Bergmann <arnd@arndb.de>,
Bart Van Assche <bvanassche@acm.org>,
Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>,
Damien Le Moal <damien.lemoal@wdc.com>,
Hou Tao <houtao1@huawei.com>,
Pavel Begunkov <asml.silence@gmail.com>,
Tejun Heo <tj@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 2/2] blk-mq: Rerun dispatching in the case of budget contention
Date: Sun, 5 Apr 2020 09:26:39 -0700 [thread overview]
Message-ID: <CAD=FV=WQZA7PGEbv_fKikGOEijP+qEEZgYXWifgjDzV6BVOUMQ@mail.gmail.com> (raw)
In-Reply-To: <20200405091446.GA3421@localhost.localdomain>
Hi,
On Sun, Apr 5, 2020 at 2:15 AM Ming Lei <ming.lei@redhat.com> wrote:
>
> @@ -103,6 +104,9 @@ static void blk_mq_do_dispatch_sched(struct blk_mq_hw_ctx *hctx)
> rq = e->type->ops.dispatch_request(hctx);
> if (!rq) {
> blk_mq_put_dispatch_budget(hctx);
> +
> + if (e->type->ops.has_work && e->type->ops.has_work(hctx))
> + blk_mq_delay_run_hw_queue(hctx, BLK_MQ_BUDGET_DELAY);
To really close the race, don't we need to run all the queues
associated with the hctx? I haven't traced it through, but I've been
assuming that the multiple "hctx"s associated with the same queue will
have the same budget associated with them and thus they can block each
other out.
-Doug
next prev parent reply other threads:[~2020-04-05 16:26 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-02 15:51 [PATCH v2 0/2] blk-mq: Fix two causes of IO stalls found in reboot testing Douglas Anderson
2020-04-02 15:51 ` [PATCH v2 1/2] blk-mq: In blk_mq_dispatch_rq_list() "no budget" is a reason to kick Douglas Anderson
2020-04-03 1:55 ` Ming Lei
2020-04-02 15:51 ` [PATCH v2 2/2] blk-mq: Rerun dispatching in the case of budget contention Douglas Anderson
2020-04-03 1:33 ` Ming Lei
2020-04-03 15:10 ` Doug Anderson
2020-04-03 15:49 ` Doug Anderson
2020-04-05 9:14 ` Ming Lei
2020-04-05 14:00 ` Doug Anderson
2020-04-05 14:57 ` Paolo Valente
2020-04-05 16:16 ` Doug Anderson
2020-04-07 10:43 ` Paolo Valente
2020-04-05 16:26 ` Doug Anderson [this message]
2020-04-07 2:14 ` Ming Lei
2020-04-07 22:04 ` Doug Anderson
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