From: Jeff Moyer <jmoyer@redhat.com>
To: Jens Axboe <jens.axboe@oracle.com>
Cc: Vivek Goyal <vgoyal@redhat.com>,
linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org
Subject: Re: [PATCH 2/4] block: Implement a blk_yield function to voluntarily give up the I/O scheduler.
Date: Thu, 15 Apr 2010 11:49:22 -0400 [thread overview]
Message-ID: <x49fx2wemwt.fsf@segfault.boston.devel.redhat.com> (raw)
In-Reply-To: <20100415103323.GW27497@kernel.dk> (Jens Axboe's message of "Thu, 15 Apr 2010 12:33:23 +0200")
Jens Axboe <jens.axboe@oracle.com> writes:
> On Wed, Apr 14 2010, Vivek Goyal wrote:
>> > @@ -1887,6 +1891,9 @@ static void cfq_dispatch_insert(struct request_queue *q, struct request *rq)
>> >
>> > cfqd->rq_in_flight[cfq_cfqq_sync(cfqq)]++;
>> > cfqq->nr_sectors += blk_rq_sectors(rq);
>> > +
>> > + if (cfq_cfqq_yield(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
>> > + cfq_yield_cfqq(cfqd, cfqq);
>>
>> Jeff,
>>
>> I am wondering if cfq_select_queue() will be a better place for yielding
>> the queue.
>>
>> if (cfq_cfqq_yield(cfqq) && RB_EMPTY_ROOT(&cfqq->sort_list))
>> goto expire;
>>
>> We can avoid one unnecessary __blk_run_queue().
>
> Agree, doing it on insert is not the right place.
I see where you're coming from, but that makes things quite a bit
trickier. I look forward to the review of *that* patch. ;-)
Cheers,
Jeff
next prev parent reply other threads:[~2010-04-15 15:49 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-14 21:17 [PATCH 0/4 v3] ext3/4: enhance fsync performance when using CFQ Jeff Moyer
2010-04-14 21:17 ` [PATCH 1/4] cfq-iosched: Keep track of average think time for the sync-noidle workload Jeff Moyer
2010-04-14 21:37 ` Vivek Goyal
2010-04-14 23:06 ` Jeff Moyer
2010-04-14 21:17 ` [PATCH 2/4] block: Implement a blk_yield function to voluntarily give up the I/O scheduler Jeff Moyer
2010-04-14 21:46 ` Vivek Goyal
2010-04-15 10:33 ` Jens Axboe
2010-04-15 15:49 ` Jeff Moyer [this message]
2010-04-14 21:17 ` [PATCH 3/4] jbd: yield the device queue when waiting for commits Jeff Moyer
2010-04-14 21:17 ` [PATCH 4/4] jbd2: yield the device queue when waiting for journal commits Jeff Moyer
2010-04-15 10:33 ` Jens Axboe
2010-04-15 10:33 ` [PATCH 0/4 v3] ext3/4: enhance fsync performance when using CFQ Jens Axboe
2010-04-15 13:05 ` Jeff Moyer
2010-04-15 13:08 ` Jens Axboe
2010-04-15 13:13 ` Jeff Moyer
2010-04-15 14:03 ` Jens Axboe
-- strict thread matches above, loose matches on Subject: below --
2010-05-18 18:20 [PATCH 0/4 v4] " Jeff Moyer
2010-05-18 18:20 ` [PATCH 2/4] block: Implement a blk_yield function to voluntarily give up the I/O scheduler Jeff Moyer
2010-05-18 21:07 ` Vivek Goyal
2010-05-18 21:44 ` Vivek Goyal
2010-06-01 20:01 ` Jeff Moyer
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