From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from max.fys.ruu.nl (max.fys.ruu.nl [131.211.32.73]) by kvack.org (8.8.7/8.8.7) with ESMTP id VAA19532 for ; Thu, 20 Nov 1997 21:00:08 -0500 Date: Fri, 21 Nov 1997 02:37:23 +0100 (MET) From: Rik van Riel Subject: Re: [PATCH *] vhand-2.1.65b released In-Reply-To: <19971120152522.39483@helix.caltech.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Joe Fouche Cc: linux-mm List-ID: On Thu, 20 Nov 1997, Joe Fouche wrote: > You wrote > > since so many people have found something wrong with vhand-2.1.6[45] > > (particularly the CPU usage), I have implemented their ideas and > > I've made the 'anti-fragmentation' unit even more agressive, since > > some people still reported crashes because of memory fragmentation... > > This one (65b) is really good. I also found that I could decrease the numbers > in /proc/sys/vm/freepages (I had them set kind of high) to improve all-around > interactive performance. All-round performance is improved, but mostly on small-memory machines... We still need to do some tuning and optimization for special cases of memory usage (linear, directory scanning, etc..). > > root 3 0.0 0.0 0 0 ? SW< 11:34 0:00 (kswapd) > root 4 1.0 0.0 0 0 ? SW 11:34 2:16 (vhand) See, the CPU usage is way to high. It might be OK for a 32Meg system, but imagine someone trying this on a 512Meg system :) Actually, someone with a 512Meg system agreed to try my patch this weekend. If things go well the patch might be ready for integration in the mainstream kernel... > A good way to test vhand, then, might be to make freepages really high and watch > as things get swapped out. :) More importantly, does the system remain stable with an ultra-low value of freepages? > > Wonder if the kernel could tune freepages automatically, based on some measure > of the performance of swap devices? Maybe the same thing would apply to some of > the numbers in struct swap_control_v5? But of course it could. Setting the value of min_free_pages to the average nr of pagefaults we had during the last time (weighed after time...) could result in a smaller number of freepages when we don't need them, and increase the number of freepages when we need the memory most. Hmm, I gotta try this one. > > Anyway, send it to Linus, it works great! :) It works great for US, small-memory users. But there are also those people around who have large (> 64M) memory systems. I won't send it to Linus unless I know it works _flawlessly_ on large-memory systems as well. Rik. ---------- Send Linux memory-management wishes to me: I'm currently looking for something to hack...