From: "Dave Young" <hidave.darkstar@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: wfg@mail.ustc.edu.cn, akpm@linux-foundation.org, jack@suse.cz,
chris@linuxinfotag.de
Subject: Re: [PATCH][BUG 10227] readahead ret value fix
Date: Fri, 14 Mar 2008 19:08:14 +0800 [thread overview]
Message-ID: <a8e1da0803140408je1f180cra6f6027b39fa07dd@mail.gmail.com> (raw)
In-Reply-To: <20080314104906.GA2898@darkstar.te-china.tietoenator.com>
On Fri, Mar 14, 2008 at 6:49 PM, Dave Young <hidave.darkstar@gmail.com> wrote:
> If the page_offset > end_index, the return value should be updated to 0,
> avoiding the redundant read_pages
>
> Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
>
> ---
> mm/readahead.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff -upr linux/mm/readahead.c linux.new/mm/readahead.c
> --- linux/mm/readahead.c 2008-03-14 18:38:12.000000000 +0800
> +++ linux.new/mm/readahead.c 2008-03-14 18:38:58.000000000 +0800
> @@ -144,8 +144,10 @@ __do_page_cache_readahead(struct address
> for (page_idx = 0; page_idx < nr_to_read; page_idx++) {
> pgoff_t page_offset = offset + page_idx;
>
> - if (page_offset > end_index)
> + if (page_offset > end_index) {
> + ret = 0;
> break;
> + }
>
> rcu_read_lock();
> page = radix_tree_lookup(&mapping->page_tree, page_offset);
>
It's not right at all, sorry for the wrong quick patch.
Anyway, please see the following debug info of me
Mar 14 18:33:51 darkstar kernel: [ 19.073085] 3c59x: Donald Becker and others.
Mar 14 18:34:39 darkstar kernel: [ 117.837850] #0 page_offset : 0,
end_index : 2 ret: 0
Mar 14 18:34:39 darkstar kernel: [ 117.837854] #1 page_offset : 0,
end_index : 2
Mar 14 18:34:39 darkstar kernel: [ 117.837861] #0 page_offset : 1,
end_index : 2 ret: 1
Mar 14 18:34:39 darkstar kernel: [ 117.837873] #1 page_offset : 1,
end_index : 2
Mar 14 18:34:39 darkstar kernel: [ 117.837888] #0 page_offset : 2,
end_index : 2 ret: 2
Mar 14 18:34:39 darkstar kernel: [ 117.837911] #1 page_offset : 2,
end_index : 2
Mar 14 18:34:39 darkstar kernel: [ 117.837922] #0 page_offset : 3,
end_index : 2 ret: 3
Mar 14 18:34:40 darkstar kernel: [ 118.051620] #0 page_offset : 3,
end_index : 2 ret: 0
Mar 14 18:34:40 darkstar kernel: [ 118.051626] zisofs : req invalid
next prev parent reply other threads:[~2008-03-14 11:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-03-14 10:49 Dave Young
2008-03-14 11:08 ` Dave Young [this message]
[not found] ` <E1Ja8Ih-0005kr-0V@localhost>
2008-03-14 11:42 ` Fengguang Wu
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=a8e1da0803140408je1f180cra6f6027b39fa07dd@mail.gmail.com \
--to=hidave.darkstar@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=chris@linuxinfotag.de \
--cc=jack@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=wfg@mail.ustc.edu.cn \
/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
all inboxes | Powered by JetHome®