[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20090326031337.GU32307@mit.edu>
Date: Wed, 25 Mar 2009 23:13:37 -0400
From: Theodore Tso <tytso@....edu>
To: Neil Brown <neilb@...e.de>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
David Rees <drees76@...il.com>, Jesper Krogh <jesper@...gh.cc>,
Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: Linux 2.6.29
On Thu, Mar 26, 2009 at 01:50:10PM +1100, Neil Brown wrote:
> I shouldn't be too hard to add some concept of total time to this.
> If we track the number of write-outs per unit time and use that together
> with a "target time for fsync" to scale the 'dirty_bytes' number, we
> might be able to auto-tune the amount of dirty space to fit the speeds
> of the drives.
>
> We would probably start with each device having a very low "max dirty"
> number which would cause writeouts to start soon. Once the device
> demonstrates that it can do n-per-second (or whatever) the VM would
> allow the "max dirty" number to drift upwards. I'm not sure how best
> to get it to move downwards if the device slows down (or the kernel
> over-estimated). Maybe it should regularly decay so that the device
> keeps have to "prove" itself.
This seems like a really cool idea.
-Ted
--
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/
Powered by blists - more mailing lists