From mboxrd@z Thu Jan 1 00:00:00 1970 From: "George Bonser" Subject: RE: [PATCH] 2.4.6-pre2 page_launder() improvements Date: Sun, 10 Jun 2001 01:38:01 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org List-ID: > > This patch has given excellent results on my laptop and my > workstation here and seems to improve kernel behaviour in tests > quite a bit. I can play mp3's unbuffered during moderate write > loads or moderately heavy IO ;) > > YMMV, please test it. If it works great for everybody I'd like > to get this improvement merged into the next -pre kernel. For the test I ran it through, it was about the same as 2.4.6-pre2 vanilla. The test I did can be simulated easilly enough. Apache with keepalives off. about 50 connections/second pulling a 10K file. Have half a gig of swap. Told the machine on boot that it had 64MB of RAM. Prestarted 250 apache children. Once everything settles down, I was about 10meg into swap and everything is running smoothly. So far so good. Now I figured I would push it a little more into swap so this being a production server, I can't really tell the world to make more connections so I do the next best thing and turn keepalives on with a timeout of 2 seconds figuring this would increase the number of apache children alive and push me deeper into swap. Restarted apache and within about 5 seconds the machine stopped responding to console input. top would not update the screen but the machine would respond to pings. I took it out of the load balancer and regained control in seconds. The 15 minute load average showed somewhere over 150 with a bazillion apache processes. Even top -q would not update when I put it back into the balancer. The load average and number of processes started to increase until I got to some point where it would just stop providing output. Again, control returned within seconds after taking it out of the balancer. As far as I could tell, I never at any time got more than 100MB into swap. Your patch did seem to keep the machine alive a little longer but that is subjective and I have no data to back that statement up. Vanilla 2.4.6-pre2 seemed to die off a little faster. Again, with both kernels, pings were fine, just no interactive at all. I was logged in over the net with no console so I could not see what was hogging the CPU bot it did not appear to be a user process. That top -q would not update tells me it was likely in the kernel because that runs as the highest priority user process. I just could not get any CPU in user space. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/