From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.inconnect.com (mail.inconnect.com [209.140.64.7]) by kvack.org (8.8.7/8.8.7) with SMTP id BAA09598 for ; Sat, 9 Jan 1999 01:28:29 -0500 Date: Fri, 8 Jan 1999 23:28:16 -0700 (MST) From: Dax Kelson Subject: 2.2.0-pre[56] swap performance poor with > 1 thrashing task In-Reply-To: <87iueiudml.fsf@atlas.CARNet.hr> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Zlatko Calusic Cc: Linus Torvalds , Steve Bergman , Andrea Arcangeli , brent verner , "Garst R. Reese" , Kalle Andersson , Ben McCann , bredelin@ucsd.edu, linux-kernel@vger.rutgers.edu, linux-mm@kvack.org, Alan Cox , "Stephen C. Tweedie" List-ID: On 7 Jan 1999, Zlatko Calusic wrote: > 2.2.0-pre5 works very good, indeed, but it still has some not > sufficiently explored nuisances: > > 1) Swap performance in pre-5 is much worse compared to pre-4 in > *certain* circumstances. I'm using quite stupid and unintelligent > program to check for raw swap speed (attached below). With 64 MB of > RAM I usually run it as 'hogmem 100 3' and watch for result which is > recently around 6 MB/sec. But when I lately decided to start two > instances of it like "hogmem 50 3 & hogmem 50 3 &" in pre-4 I got 2 x > 2.5 MB/sec and in pre-5 it is only 2 x 1 MB/sec and disk is making > very weird and frightening sounds. My conclusion is that now (pre-5) > system behaves much poorer when we have more than one thrashing > task. *Please*, check this, it is a quite serious problem. I just tried this on 2.2.0-pre6 PentiumII 412Mhz, 128MB SDRAM, one IDE disk (/ & swap). ./hogmem 100 3 (no swapping) Memory speed: 167.60 MB/sec ./hogmem 200 3 Memory speed: 9.01 MB/sec ./hogmem 100 3 & ./hogmem 100 3 Memory speed: 0.96 MB/sec Memory speed: 0.96 MB/sec ./hogmem 100 3 (no swap) Memory speed: 180.18 MB/sec ./hogmem 200 3 Memory speed: 8.68 MB/sec I then tried ./hogmem 200 3 & find / (on about 1.5GB of data on ext2 and vfat and nfs repeatedly) And launched netscape. After 45 mins, I didn't restart the find, and about 3 mins later the hogmem completed at 0.75MB/sec. Netscape was surprisingly responsive however. Dax Kelson -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org