From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <20000420210732.5417.qmail@web123.yahoomail.com> Date: Thu, 20 Apr 2000 14:07:32 -0700 (PDT) From: Cacophonix Subject: swapping from pagecache? MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: linux-mm@kvack.org List-ID: Hello all, I've been running a few webserver tests with 2.3.99-pre6-2, and there seems to be some difference in behavior between 2.2.x and 2.3.99-pre. Specifically, on 2.3.99, it appears that unused pages from the page cache are swapped to disk, while in 2.2, unused pages are not swapped. As a result, performance on 2.3.99-pre drops to below 2.2. levels under such a scenario. For example, a procinfo on 2.3.99-pre6 reports: Linux 2.3.99-pre6 (root@pc46) (gcc egcs-2.91.66) #8 Sun Apr 16 14:28:40 PDT 2000 1CPU [pc46] Memory: Total Used Free Shared Buffers Cached Mem: 513120 511220 1900 0 6280 442264 Swap: 265064 41984 223080 Bootup: Thu Apr 20 12:12:46 2000 Load average: 4.02 3.40 2.05 2/39 2287 user : 0:00:01.40 14.0% page in : 5191 disk 1: 62r 166w nice : 0:00:00.01 0.1% page out: 904 disk 2: 1235r 0w system: 0:00:04.65 46.5% swap in : 72 idle : 0:00:03.94 39.4% swap out: 787 uptime: 0:31:28.18 context : 2421 irq 0: 1000 timer irq 10: 1817 sym53c8xx irq 1: 0 keyboard irq 11: 21 eth1 irq 2: 0 cascade [4] irq 12: 0 PS/2 Mouse irq 3: 0 irq 13: 0 fpu irq 4: 0 irq 15: 54620 NetGear GA620 Gigabi Note that the value under shared is 0. A procinfo under 2.2.16-pre1 with a similar scenario shows memory being shared (mainly by the web server, which has an internal cache), and does not swap at all. Any comments on this behavior? (shm is mounted of course). Thanks for any advice. cheers, karthik __________________________________________________ Do You Yahoo!? Send online invitations with Yahoo! Invites. http://invites.yahoo.com -- 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.eu.org/Linux-MM/