Re: 2.4.14-pre6

From: Chris Mason <mason@suse.com>
To: Andrew Morton <akpm@zip.com.au>, Neil Brown <neilb@cse.unsw.edu.au>
Cc: Linus Torvalds <torvalds@transmeta.com>,
	Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Andrea Arcangeli <andrea@suse.de>
Subject: Re: 2.4.14-pre6
Date: Thu, 01 Nov 2001 16:28:44 -0500	[thread overview]
Message-ID: <334750000.1004650124@tiny> (raw)
In-Reply-To: <3BE1B6CD.7DA43A6C@zip.com.au>
In-Reply-To: message from Linus Torvalds on Wednesday October 31,	<Pine.LNX.4.33.0110310809200.32460-100000@penguin.transmeta.com> <15329.8658.642254.284398@notabene.cse.unsw.edu.au> <3BE1B6CD.7DA43A6C@zip.com.au>

On Thursday, November 01, 2001 12:55:41 PM -0800 Andrew Morton
<akpm@zip.com.au> wrote:

> Oh.  I have a gripe concerning prune_icache().  The design
> idea behind keventd is that it's a "process context bottom
> half handler".  It's used for things like cardbus hotplug
> interrupt handlers, handling tty hangups, etc.  It should
> probably run SCHED_FIFO.
> 
> Using keventd to synchronously flush large amounts of 
> data out to disk constitutes gross abuse - it's being blocked
> from performing its designed duties for many seconds.  Can we
> please not do that?  We already have kswapd, kupdate, bdflush,
> which should be sufficient.

One of the worst parts of prune_icache was that if a journaled
FS needed to log dirty inodes, kswapd would wait on the log, who was
probably waiting on kswapd.  Thus the dirty_inode call, which I'd like to
get rid of.

I don't think kupdate or bdflush are suitable to flush the dirty inodes,
kupdate shouldn't do memory pressure and bdflush shouldn't wait on the log.
So how about a new kinoded?

-chris