From: Christoph Hellwig <hch@lst.de>
To: Salman Qazi <sqazi@google.com>
Cc: Jens Axboe <axboe@kernel.dk>, Ming Lei <ming.lei@redhat.com>,
Bart Van Assche <bvanassche@acm.org>,
linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
Jesse Barnes <jsbarnes@google.com>,
Gwendal Grignou <gwendal@google.com>,
Hannes Reinecke <hare@suse.com>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v2] block: Limit number of items taken from the I/O scheduler in one go
Date: Fri, 24 Apr 2020 08:42:06 +0200 [thread overview]
Message-ID: <20200424064206.GA23666@lst.de> (raw)
In-Reply-To: <20200424061529.GA23303@lst.de>
On Fri, Apr 24, 2020 at 08:15:29AM +0200, Christoph Hellwig wrote:
> This is a weird loop. I'd split the code betweem the again label and
> the run_again check here into a __blk_mq_sched_dispatch_requests
> helper, and then you can do:
>
> if (__blk_mq_sched_dispatch_requests()) {
> if (__blk_mq_sched_dispatch_requests())
> blk_mq_run_hw_queue(hctx, true);
> }
>
> here. Preferably with ha good comment explaining the logic.
Also I wonder if inverting the return values in the lower level function
would make things a little more readable - a true return suggests
everything worked fine. Alternative 0 for sucess and -EAGAIN for needs
a retry also would be pretty self-documenting.
next prev parent reply other threads:[~2020-04-24 6:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 21:05 [PATCH v2] block: Limit number of items taken from the I/O scheduler in one go Salman Qazi
2020-04-23 21:30 ` Jens Axboe
2020-04-24 1:41 ` Salman Qazi
2020-04-24 6:15 ` Christoph Hellwig
2020-04-24 6:42 ` Christoph Hellwig [this message]
-- strict thread matches above, loose matches on Subject: below --
2020-04-23 21:48 Salman Qazi
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