linux-kernel - Re: [PATCH 11/12] vmscan: Write out dirty pages in batch

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100615110102.GD31051@infradead.org>
Date:	Tue, 15 Jun 2010 07:01:02 -0400
From:	Christoph Hellwig <hch@...radead.org>
To:	Rik van Riel <riel@...hat.com>
Cc:	Dave Chinner <david@...morbit.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Mel Gorman <mel@....ul.ie>, linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
	Chris Mason <chris.mason@...cle.com>,
	Nick Piggin <npiggin@...e.de>,
	Johannes Weiner <hannes@...xchg.org>,
	Christoph Hellwig <hch@...radead.org>,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Subject: Re: [PATCH 11/12] vmscan: Write out dirty pages in batch

On Mon, Jun 14, 2010 at 09:16:29PM -0400, Rik van Riel wrote:
> >Besides, there really isn't the right context in the block layer to
> >be able to queue and prioritise large amounts of IO without
> >significant penalties to some higher layer operation.
> 
> Can we kick flushing for the whole inode at once from
> vmscan.c?

kswapd really should be a last effort tool to clean filesystem pages.
If it does enough I/O for this to matter significantly we need to
fix the VM to move more work to the flusher threads instead of trying
to fix kswapd.  

> Would it be hard to add a "please flush this file"
> way to call the filesystem flushing threads?

We already have that API, in Jens' latest tree that's
sync_inodes_sb/writeback_inodes_sb.  We could also add a non-waiting
variant if required, but I think the big problem with kswapd is that
we want to wait on I/O completion under circumstances.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/