Subject: Re: Recent buffer cache fixes; softdep win(?)
To: Markus W Kilbinger <firstname.lastname@example.org>
From: Daniel Carosone <email@example.com>
Date: 02/01/2004 23:09:32
Content-Type: text/plain; charset=us-ascii
On Sat, Jan 31, 2004 at 12:21:17PM +0100, Markus W Kilbinger wrote:
> ... seem to make my sparc ipx the first time run stable with softdep
> Before it ran into some kind of deadlock with more and more decreasing
> responsiveness under heavy (disk) load...
That's very interesting, and encouraging though for the wrong reasons.
Was this a problem you had since a long time ago, or only in the past
few weeks? Because the behaviour that this patch changed is only a
few weeks old.
If there is a deadlock in the system somewhere, it's still there -
it's just no longer being triggered so readily. Such problems have
been exposed by the new bufcache behaviour with softdep, in that we
can now generate a huge flood of metadata IO at once - and which this
patch may do a better job of hiding some of that.
But if you saw this problem with softdep before a few weeks ago, the
underlying problem is very likely still there.
Are you using something like cgd or raidframe on this ipx? How much
RAM does it have (probably not that much, right)?
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