From: Nick Piggin <nickpiggin@yahoo.com.au>
To: Arjan van de Ven <arjan@infradead.org>
Cc: Andrew Morton <akpm@osdl.org>, linux-mm@kvack.org
Subject: Re: follow_page()
Date: Thu, 11 Nov 2004 23:27:37 +1100 [thread overview]
Message-ID: <41935AB9.7000101@yahoo.com.au> (raw)
In-Reply-To: <1100175387.4387.1.camel@laptop.fenrus.org>
Arjan van de Ven wrote:
>>>so in the race case you get the hit of those 4000 cycles... still optimizes the non-race case
>>>(so I'd agree that nothing should depend on this function dirtying it; it's a pre-dirty that's an
>>>optimisation)
>>>
>>
>>Only it doesn't mark the pte dirty, does it?
>
>
> sounds like someone subsequently "optimized" it...
> predirtying the pte is still worth it imo....
> but when we do that we better put a big fat comment there.
>
Well, if you write into the page returned via follow_page, that
isn't going to dirty the pte by itself... so it is a bit of a
hit and miss regarding whether the page really will get dirtied
through that pte in the near future (I don't know, maybe that
is generally what happens with normal usage patterns?).
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"aart@kvack.org"> aart@kvack.org </a>
next prev parent reply other threads:[~2004-11-11 12:27 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-11 10:40 follow_page() Andrew Morton
2004-11-11 10:56 ` follow_page() Arjan van de Ven
2004-11-11 11:06 ` follow_page() Andrew Morton
2004-11-11 11:10 ` follow_page() Arjan van de Ven
2004-11-11 11:58 ` follow_page() Nick Piggin
2004-11-11 12:11 ` follow_page() Andrew Morton
2004-11-11 12:20 ` follow_page() Nick Piggin
2004-11-11 12:16 ` follow_page() Arjan van de Ven
2004-11-11 12:27 ` Nick Piggin [this message]
2004-11-11 12:46 ` follow_page() Arjan van de Ven
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=41935AB9.7000101@yahoo.com.au \
--to=nickpiggin@yahoo.com.au \
--cc=akpm@osdl.org \
--cc=arjan@infradead.org \
--cc=linux-mm@kvack.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