From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3A63ED75.53094939@sw.com.sg> Date: Tue, 16 Jan 2001 14:43:01 +0800 Content-Class: urn:content-classes:message From: "Vlad Bolkhovitine" MIME-Version: 1.0 Subject: Re: mmap()/VM problems in 2.4.0 References: Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Mike Galbraith Cc: Zlatko Calusic , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: Mike Galbraith wrote: > > On 15 Jan 2001, Zlatko Calusic wrote: > > > "Vlad Bolkhovitine" writes: > > > > > Here is updated info for 2.4.1pre3: > > > > > > Size is MB, BlkSz is Bytes, Read, Write, and Seeks are MB/sec > > > > > > with mmap() > > > > > > File Block Num Seq Read Rand Read Seq Write Rand Write > > > Dir Size Size Thr Rate (CPU%) Rate (CPU%) Rate (CPU%) Rate (CPU%) > > > ------- ------ ------- --- ----------- ----------- ----------- ----------- > > > . 1024 4096 2 1.089 1.24% 0.235 0.45% 1.118 4.11% 0.616 1.41% > > > [...] > > > Mmap() performance dropped dramatically down to almost unusable level. Plus, > > > system was unusable during test: "vmstat 1" updated results every 1-2 _MINUTES_! > > > > > > > You need Marcelo's patch. Please apply and retest. > > My box thinks quite highly of that patch fwiw, but insists that he needs > to apply Jens Axboes' blk patch first ;-) (Not because of tiobench) New data: 2.4.1pre3 + Marcelo's patch File Block Num Seq Read Rand Read Seq Write Rand Write Dir Size Size Thr Rate (CPU%) Rate (CPU%) Rate (CPU%) Rate (CPU%) ------- ------ ------- --- ----------- ----------- ----------- ----------- . 1024 4096 2 12.68 9.23% 0.497 0.92% 10.57 15.3% 0.594 1.44% The same performance level as for 2.4.0. No improvement. 2.4.1pre3 + Marcelo's patch + Jens Axboes' blk-13B patch File Block Num Seq Read Rand Read Seq Write Rand Write Dir Size Size Thr Rate (CPU%) Rate (CPU%) Rate (CPU%) Rate (CPU%) ------- ------ ------- --- ----------- ----------- ----------- ----------- . 1024 4096 2 12.47 10.0% 0.504 1.13% 9.998 16.5% 0.735 2.21% No significant difference, just noise. IMHO, it is expected, since 2 threads simply aren't enough to launch blk patch's mechanisms > -Mike -- 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/