From: Andrew Morton <akpm@osdl.org>
To: Marcelo Tosatti <marcelo.tosatti@cyclades.com>
Cc: linux-mm@kvack.org, piggin@cyberone.com.au
Subject: Re: [PATCH] kswapd shall not sleep during page shortage
Date: Tue, 9 Nov 2004 16:28:01 -0800 [thread overview]
Message-ID: <20041109162801.7f7ca242.akpm@osdl.org> (raw)
In-Reply-To: <20041109203143.GC8414@logos.cnet>
Marcelo Tosatti <marcelo.tosatti@cyclades.com> wrote:
>
> Back to arguing in favour of my patch - it seemed to me that kswapd could
> go to sleep leaving allocators which can't reclaim pages themselves in a
> bad situation.
Yes, but those processes would be sleeping in blk_congestion_wait() during,
say, a GFP_NOIO/GFP_NOFS allocation attempt. And in that case, they may be
holding locks whcih prevent kswapd from being able to do any work either.
> It would have to be waken up by another instance of alloc_pages to then
> execute and start doing its job, while if it was executing already (madly
> scanning as you say), the chance it would find freeable pages quite
> earlier.
>
> Note that not only disk IO can cause pages to become freeable. A user
> can give up its reference on pagecache page for example (leaving
> the page on LRU to be found and freed by kswapd).
yup. Or munlock(), or direct-io completion.
--
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:[~2004-11-10 0:28 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-11-09 16:46 [PATCH] kswapd shall not sleep during page shortage Marcelo Tosatti
2004-11-09 20:19 ` Andrew Morton
2004-11-09 17:41 ` Marcelo Tosatti
2004-11-09 21:33 ` Andrew Morton
2004-11-09 18:26 ` Marcelo Tosatti
2004-11-09 22:22 ` Andrew Morton
2004-11-09 20:31 ` Marcelo Tosatti
2004-11-10 0:28 ` Andrew Morton [this message]
2004-11-09 23:16 ` Marcelo Tosatti
2004-11-09 23:34 ` Marcelo Tosatti
2004-11-10 2:53 ` Andrew Morton
2004-11-10 18:14 ` Marcelo Tosatti
2004-11-10 22:08 ` Andrew Morton
2004-11-10 0:56 ` Nick Piggin
2004-11-10 2:49 ` Nick Piggin
2004-11-10 2:56 ` Andrew Morton
2004-11-10 3:12 ` Nick Piggin
2004-11-10 3:18 ` Andrew Morton
2004-11-10 3:27 ` Nick Piggin
2004-11-10 4:15 ` Nick Piggin
2004-11-10 8:17 ` Marcelo Tosatti
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=20041109162801.7f7ca242.akpm@osdl.org \
--to=akpm@osdl.org \
--cc=linux-mm@kvack.org \
--cc=marcelo.tosatti@cyclades.com \
--cc=piggin@cyberone.com.au \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.