From: Xifengfei <xi.fengfei@h3c.com>
To: Coly Li <colyli@suse.de>
Cc: "linux-bcache@vger.kernel.org" <linux-bcache@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kent.overstreet@gmail.com" <kent.overstreet@gmail.com>
Subject: Re: [PATCH] bcache: remove the redundant judgment on bi_size
Date: Mon, 30 Aug 2021 06:29:45 +0000 [thread overview]
Message-ID: <ed49f33da50e4f5c88f986c8ed239e78@h3c.com> (raw)
(Sorry, there was an obvious typo in the last email)
Thanks a lot. I understand the purpose.
So is the original judgment process too complicated? Can we judge bi_size directly? This will be more concise
@@ -423,7 +423,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
add_sequential(task);
i->sequential = 0;
found:
- if (i->sequential + bio->bi_iter.bi_size > i->sequential)
+ if (bio->bi_iter.bi_size)
i->sequential += bio->bi_iter.bi_size;
i->last = bio_end_sector(bio);
Thanks
Fengfei
-----邮件原件-----
发件人: Coly Li [mailto:colyli@suse.de]
发送时间: 2021年8月29日 15:50
收件人: xifengfei (RD) <xi.fengfei@h3c.com>
抄送: linux-bcache@vger.kernel.org; linux-kernel@vger.kernel.org; kent.overstreet@gmail.com
主题: Re: [PATCH] bcache: remove the redundant judgment on bi_size
On 8/29/21 12:49 PM, Fengfei Xi wrote:
> The bi_size is unsigned int type data not less than 0, so we can
> directly add bi_size without extra judgment
>
> Signed-off-by: Fengfei Xi <xi.fengfei@h3c.com>
NACK. The check is necessary to avoid redundant and unnecessary memory write.
Coly Li
> ---
> drivers/md/bcache/request.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/md/bcache/request.c b/drivers/md/bcache/request.c
> index 6d1de889b..2788eec3a 100644
> --- a/drivers/md/bcache/request.c
> +++ b/drivers/md/bcache/request.c
> @@ -423,9 +423,7 @@ static bool check_should_bypass(struct cached_dev *dc, struct bio *bio)
> add_sequential(task);
> i->sequential = 0;
> found:
> - if (i->sequential + bio->bi_iter.bi_size > i->sequential)
> - i->sequential += bio->bi_iter.bi_size;
> -
> + i->sequential += bio->bi_iter.bi_size;
> i->last = bio_end_sector(bio);
> i->jiffies = jiffies + msecs_to_jiffies(5000);
> task->sequential_io = i->sequential;
next reply other threads:[~2021-08-30 6:30 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-30 6:29 Xifengfei [this message]
2021-08-31 1:35 ` [PATCH] bcache: remove the redundant judgment on bi_size Coly Li
-- strict thread matches above, loose matches on Subject: below --
2021-08-31 2:05 Xifengfei
2021-08-30 6:23 Xifengfei
2021-08-29 4:49 Fengfei Xi
2021-08-29 7:49 ` Coly Li
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