From: Eric Biggers <ebiggers@kernel.org>
To: zhou_xianrong <zhou_xianrong@sohu.com>
Cc: dm-devel@redhat.com, linux-kernel@vger.kernel.org,
agk@redhat.com, snitzer@redhat.com, wanbin.wang@transsion.com,
haizhou.song@transsion.com,
"xianrong.zhou" <xianrong.zhou@transsion.com>,
"yuanjiong . gao" <yuanjiong.gao@transsion.com>,
"ruxian . feng" <ruxian.feng@transsion.com>
Subject: Re: [PATCH] dm-verity:unnecessary data blocks that need not read hash blocks
Date: Mon, 6 Jan 2020 19:14:29 -0800 [thread overview]
Message-ID: <20200107031429.GA705@sol.localdomain> (raw)
In-Reply-To: <20200107024843.8660-1-zhou_xianrong@sohu.com>
On Tue, Jan 07, 2020 at 10:48:43AM +0800, zhou_xianrong wrote:
> Subject: [PATCH] dm-verity:unnecessary data blocks that need not read
Please use a proper commit subject. It should begin with "dm verity: " and use
the imperative tense to describe the change, e.g.
dm verity: don't prefetch hash blocks for already-verified data
Also this should have been "PATCH v2", not simply PATCH, since you already sent
out a previous version.
You also sent out multiple copies of this email for some reason, so I just chose
one arbitrarily to reply to...
> diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
> index 4fb33e7..4127711 100644
> --- a/drivers/md/dm-verity-target.c
> +++ b/drivers/md/dm-verity-target.c
> @@ -611,8 +611,27 @@ static void verity_prefetch_io(struct work_struct *work)
>
> static void verity_submit_prefetch(struct dm_verity *v, struct dm_verity_io *io)
> {
> + sector_t block = io->block;
> + unsigned int n_blocks = io->n_blocks;
> struct dm_verity_prefetch_work *pw;
>
> + if (v->validated_blocks) {
> + while (n_blocks) {
> + if (unlikely(!test_bit(block, v->validated_blocks)))
> + break;
> + block++;
> + n_blocks--;
> + }
> + while (n_blocks) {
> + if (unlikely(!test_bit(block + n_blocks - 1,
> + v->validated_blocks)))
> + break;
> + n_blocks--;
> + }
> + if (!n_blocks)
> + return;
> + }
This looks fine now, though it's a bit more verbose than necessary, and I don't
think unlikely() will make any difference here. Consider simplifying it to:
if (v->validated_blocks) {
while (n_blocks && test_bit(block, v->validated_blocks)) {
block++;
n_blocks--;
}
while (n_blocks && test_bit(block + n_blocks - 1,
v->validated_blocks))
n_blocks--;
if (!n_blocks)
return;
}
next parent reply other threads:[~2020-01-07 3:14 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200107024843.8660-1-zhou_xianrong@sohu.com>
2020-01-07 3:14 ` Eric Biggers [this message]
2019-12-16 2:02 Reply [PATCH] dm-verity: unnecessary data blocks that need not read hash blocks xianrong.zhou(周先荣)
2019-12-16 18:50 ` Eric Biggers
[not found] <20191211033240.169-1-zhou_xianrong@yeah.net>
2019-12-14 6:58 ` Eric Biggers
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=20200107031429.GA705@sol.localdomain \
--to=ebiggers@kernel.org \
--cc=agk@redhat.com \
--cc=dm-devel@redhat.com \
--cc=haizhou.song@transsion.com \
--cc=linux-kernel@vger.kernel.org \
--cc=ruxian.feng@transsion.com \
--cc=snitzer@redhat.com \
--cc=wanbin.wang@transsion.com \
--cc=xianrong.zhou@transsion.com \
--cc=yuanjiong.gao@transsion.com \
--cc=zhou_xianrong@sohu.com \
/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).