From: Bart Van Assche <bvanassche@acm.org>
To: Damien Le Moal <Damien.LeMoal@wdc.com>, Jens Axboe <axboe@kernel.dk>
Cc: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
Christoph Hellwig <hch@lst.de>, Jaegeuk Kim <jaegeuk@kernel.org>,
Niklas Cassel <Niklas.Cassel@wdc.com>,
Hannes Reinecke <hare@suse.de>
Subject: Re: [PATCH 3/4] block/mq-deadline: Stop using per-CPU counters
Date: Fri, 24 Sep 2021 19:59:22 -0700 [thread overview]
Message-ID: <81cd7cea-6060-4500-8af3-cd324aef61de@acm.org> (raw)
In-Reply-To: <DM6PR04MB7081B7096944F8115A8BE2B6E7A49@DM6PR04MB7081.namprd04.prod.outlook.com>
On 9/24/21 03:58, Damien Le Moal wrote:
> On 2021/09/24 8:27, Bart Van Assche wrote:
>> -/* I/O statistics for all I/O priorities (enum dd_prio). */
>> -struct io_stats {
>> - struct io_stats_per_prio stats[DD_PRIO_COUNT];
>> + uint32_t inserted;
>> + uint32_t merged;
>> + uint32_t dispatched;
>> + atomic_t completed;
>
> Why not use 64-bits types (regular unsigned long long and atomic64_t) ?
Even 64-bit counters can overflow. Using 32-bit counters makes it easier to
trigger an overflow of these counters.
Thanks,
Bart.
next prev parent reply other threads:[~2021-09-25 2:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 23:23 [PATCH 0/4] Restore I/O priority support in the mq-deadline scheduler Bart Van Assche
2021-09-23 23:26 ` [PATCH 1/4] block/mq-deadline: Improve request accounting further Bart Van Assche
2021-09-23 23:26 ` [PATCH 2/4] block/mq-deadline: Add an invariant check Bart Van Assche
2021-09-24 10:54 ` Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
2021-09-23 23:26 ` [PATCH 3/4] block/mq-deadline: Stop using per-CPU counters Bart Van Assche
2021-09-24 10:58 ` Damien Le Moal
2021-09-25 2:59 ` Bart Van Assche [this message]
2021-09-27 0:19 ` Damien Le Moal
2021-09-27 2:38 ` Bart Van Assche
2021-09-27 3:41 ` Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
2021-09-23 23:26 ` [PATCH 4/4] block/mq-deadline: Prioritize high-priority requests Bart Van Assche
2021-09-24 11:08 ` Damien Le Moal
2021-09-27 20:03 ` Bart Van Assche
2021-09-24 10:54 ` [PATCH 1/4] block/mq-deadline: Improve request accounting further Damien Le Moal
2021-09-27 15:53 ` Niklas Cassel
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=81cd7cea-6060-4500-8af3-cd324aef61de@acm.org \
--to=bvanassche@acm.org \
--cc=Damien.LeMoal@wdc.com \
--cc=Niklas.Cassel@wdc.com \
--cc=axboe@kernel.dk \
--cc=hare@suse.de \
--cc=hch@lst.de \
--cc=jaegeuk@kernel.org \
--cc=linux-block@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).