From: Lai Jiangshan <laijs@cn.fujitsu.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <rostedt@goodmis.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] ring_bufer: fix BUF_PAGE_SIZE
Date: Sat, 20 Dec 2008 17:31:25 +0800 [thread overview]
Message-ID: <494CBB6D.9070106@cn.fujitsu.com> (raw)
In-Reply-To: <20081218124803.GA31763@elte.hu>
Ingo Molnar wrote:
> * Lai Jiangshan <laijs@cn.fujitsu.com> wrote:
>
>> impact: make BUF_PAGE_SIZE changeable.
>>
>> Except allocating/freeing page and the code using PAGE_MASK,
>> all code expect buffer_page's length is BUF_PAGE_SIZE.
>>
>> This patch make this behavior more concordant.
>>
[...]
>
> hm, why? Non-order-0 allocations are pretty evil - why would we ever want
> to do them?
>
> Ingo
>
I think since we introduce BUF_PAGE_SIZE instead of PAGE_SIZE for
buffer_page, we should make it changeable. We can use Non-order-0
allocations, but it doesn't mean we have to use Non-order-0 allocations.
In the old codes, these lines confuse me:
return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE);
addr &= PAGE_MASK;
This patch mostly make the codes concordant.
Lai
next prev parent reply other threads:[~2008-12-20 9:35 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-17 9:48 [PATCH] ring_bufer: fix BUF_PAGE_SIZE Lai Jiangshan
2008-12-18 12:48 ` Ingo Molnar
2008-12-20 9:31 ` Lai Jiangshan [this message]
2008-12-21 8:55 ` Ingo Molnar
2008-12-22 18:37 ` Steven Rostedt
2008-12-22 17:57 ` Steven Rostedt
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=494CBB6D.9070106@cn.fujitsu.com \
--to=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=rostedt@goodmis.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