From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: xmm2 - monitor Linux MM active/inactive lists graphically References: Reply-To: zlatko.calusic@iskon.hr From: Zlatko Calusic Date: 25 Oct 2001 11:07:05 +0200 In-Reply-To: (Linus Torvalds's message of "Wed, 24 Oct 2001 21:19:55 -0700 (PDT)") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds Cc: Marcelo Tosatti , linux-mm@kvack.org, lkml List-ID: Linus Torvalds writes: > On 25 Oct 2001, Zlatko Calusic wrote: > > > > Sure. Output of 'vmstat 1' follows: > > > > 1 0 0 0 254552 5120 183476 0 0 12 24 178 438 2 37 60 > > 0 1 0 0 137296 5232 297760 0 0 4 5284 195 440 3 43 54 > > 1 0 0 0 126520 5244 308260 0 0 0 10588 215 230 0 3 96 > > 0 2 0 0 117488 5252 317064 0 0 0 8796 176 139 1 3 96 > > 0 2 0 0 107556 5264 326744 0 0 0 9704 174 78 0 3 97 > > This does not look like a VM issue at all - at this point you're already > getting only 10MB/s, yet the VM isn't even involved (there's definitely no > VM pressure here). That's true, I'll admit. Anyway, -ac kernels don't have the problem, and I was misleaded by the fact that only VM implementation differs in those two branches (at least I think so). > > > Notice how there's planty of RAM. I'm writing sequentially to a file > > on the ext2 filesystem. The disk I'm writing on is a 7200rpm IDE, > > capable of ~ 22 MB/s and I'm still getting only ~ 9 MB/s. Weird! > > Are you sure you haven't lost some DMA setting or something? > No. Setup is fine. I wouldn't make such a mistake. :) If the disk were in some PIO mode, CPU usage would be much higher, but it isn't. This all definitely looks like a problem either in the bdflush daemon, or request queue/elevator, but unfortunately I don't have enough knowledge of that areas to pinpoint it more precisely. -- Zlatko -- 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/