From: "Stephen C. Tweedie" <sct@redhat.com>
To: Kanoj Sarcar <kanoj@google.engr.sgi.com>
Cc: Andrea Arcangeli <andrea@suse.de>, Ben LaHaise <bcrl@redhat.com>,
riel@nl.linux.org, Linus Torvalds <torvalds@transmeta.com>,
linux-mm@kvack.org, Stephen Tweedie <sct@redhat.com>
Subject: Re: [patch] take 2 Re: PG_swap_entry bug in recent kernels
Date: Mon, 10 Apr 2000 20:10:21 +0100 [thread overview]
Message-ID: <20000410201021.V17648@redhat.com> (raw)
In-Reply-To: <200004082147.OAA75650@google.engr.sgi.com>; from kanoj@google.engr.sgi.com on Sat, Apr 08, 2000 at 02:47:29PM -0700
Hi,
On Sat, Apr 08, 2000 at 02:47:29PM -0700, Kanoj Sarcar wrote:
>
> You have answered your own question in a later email. I quote you:
> "Are you using read_swap_cache from any
> swapin event? The problem is swapin can't use read_swap_cache because with
> read_swap_cache we would never know if we're doing I/O on an inactive swap
> entry"
Right. The way the swap synchronisation always worked was that
we must have a swap cache entry before _any_ IO, so the page lock
bit on that swap cache page could also serve as an IO lock on the
swap entry. (Actually, it didn't _always_ work that way, but that's
the basic mechanism with the current swap cache.)
That relied on the swapper being able to do an atomic operation to
search for a page cache page, and to create a new page and lock it
if it wasn't already there. That was made atomic only by use of the
big lock. If you don't have all page cache activity using that lock,
then yes, you'll need the page cache lock while you set all of this
up.
--Stephen
--
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.eu.org/Linux-MM/
next prev parent reply other threads:[~2000-04-10 19:10 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2000-04-03 22:22 PG_swap_entry bug in recent kernels Ben LaHaise
2000-04-04 15:06 ` Andrea Arcangeli
2000-04-04 15:46 ` Rik van Riel
2000-04-04 16:50 ` Andrea Arcangeli
2000-04-04 17:06 ` Ben LaHaise
2000-04-04 18:03 ` Andrea Arcangeli
2000-04-06 22:11 ` [patch] take 2 " Ben LaHaise
2000-04-07 10:45 ` Andrea Arcangeli
2000-04-07 11:29 ` Rik van Riel
2000-04-07 12:00 ` Andrea Arcangeli
2000-04-07 12:54 ` Rik van Riel
2000-04-07 13:14 ` Andrea Arcangeli
2000-04-07 20:12 ` Kanoj Sarcar
2000-04-07 23:26 ` Andrea Arcangeli
2000-04-08 0:11 ` Kanoj Sarcar
2000-04-08 0:37 ` Kanoj Sarcar
2000-04-08 13:20 ` Andrea Arcangeli
2000-04-08 21:39 ` Kanoj Sarcar
2000-04-08 23:02 ` Andrea Arcangeli
2000-04-08 23:18 ` Kanoj Sarcar
2000-04-08 23:58 ` Andrea Arcangeli
2000-04-08 13:30 ` Andrea Arcangeli
2000-04-08 17:39 ` Andrea Arcangeli
2000-04-07 23:54 ` Andrea Arcangeli
2000-04-08 0:15 ` Kanoj Sarcar
2000-04-08 13:14 ` Andrea Arcangeli
2000-04-08 21:47 ` Kanoj Sarcar
2000-04-08 23:10 ` Andrea Arcangeli
2000-04-08 23:21 ` Kanoj Sarcar
2000-04-08 23:39 ` Andrea Arcangeli
2000-04-09 0:40 ` Kanoj Sarcar
2000-04-10 8:55 ` andrea
2000-04-11 2:45 ` Kanoj Sarcar
2000-04-11 16:22 ` Andrea Arcangeli
2000-04-11 17:40 ` Rik van Riel
2000-04-11 18:20 ` Kanoj Sarcar
2000-04-21 18:23 ` Andrea Arcangeli
2000-04-21 21:00 ` Rik van Riel
2000-04-22 1:12 ` Andrea Arcangeli
2000-04-22 1:51 ` Linus Torvalds
2000-04-22 18:29 ` Rik van Riel
2000-04-22 19:58 ` Linus Torvalds
2000-04-11 18:26 ` Kanoj Sarcar
2000-04-10 19:10 ` Stephen C. Tweedie [this message]
2000-04-08 0:04 ` Andrea Arcangeli
[not found] <yttem7xstk2.fsf@vexeta.dc.fi.udc.es>
2000-04-23 0:52 ` Andrea Arcangeli
[not found] <yttk8ho26s8.fsf@vexeta.dc.fi.udc.es>
2000-04-23 16:07 ` Andrea Arcangeli
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=20000410201021.V17648@redhat.com \
--to=sct@redhat.com \
--cc=andrea@suse.de \
--cc=bcrl@redhat.com \
--cc=kanoj@google.engr.sgi.com \
--cc=linux-mm@kvack.org \
--cc=riel@nl.linux.org \
--cc=torvalds@transmeta.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 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.