From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <028001c11cf0$e5becca0$b6562341@cfl.rr.com> From: "Mike Black" References: Subject: Re: [RFC][DATA] re "ongoing vm suckage" Date: Sat, 4 Aug 2001 10:22:19 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds , Ben LaHaise Cc: Daniel Phillips , Rik van Riel , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton List-ID: I'm testing 2.4.8-pre4 -- MUCH better interactivity behavior now. I've been testing ext3/raid5 for several weeks now and this is usable now. My system is Dual 1Ghz/2GRam/4GSwap fibrechannel. But...the single thread i/o performance is down. Previously I was getting about 60MB/sec on one thread for Seq Read -- now it's 40MB/sec. Here's the run: tiobench.pl --size 4000 Size is MB, BlkSz is Bytes, Read, Write, and Seeks are MB/secd . -T File Block Num Seq Read Rand Read Seq Write Rand Write Dir Size Size Thr Rate (CPU%) Rate (CPU%) Rate (CPU%) Rate (CPU%) ------- ------ ------- --- ----------- ----------- ----------- ----------- . 4000 4096 1 40.62 73.8% 0.675 1.38% 27.08 43.6% 1.207 2.00% . 4000 4096 2 17.02 30.2% 0.761 1.63% 16.84 29.9% 1.270 1.78% . 4000 4096 4 14.96 26.8% 0.885 2.13% 13.75 31.2% 1.278 1.69% . 4000 4096 8 13.39 21.5% 0.952 2.48% 12.46 33.2% 1.188 1.48% During the 4-thread run there was one long pause (instead of being totally unusable before with even 2 threads). Didn't notice any pauses during 8 threads. I"m seeing a lot more CPU Usage for the 1st thread than previous tests -- perhaps we've shortened the queue too much and it's throttling the read? Why would CPU usage go up and I/O go down? Here's a previous test (only 1 thread as 2 threads became unusable). File Block Num Seq Read Rand Read Seq Write Rand Write Dir Size Size Thr Rate (CPU%) Rate (CPU%) Rate (CPU%) Rate (CPU%) ------- ------ ------- --- ----------- ----------- ----------- ----------- . 4000 4096 1 66.69 53.6% 0.829 1.43% 27.64 41.6% 1.287 0.74% ----- Original Message ----- From: "Linus Torvalds" To: "Ben LaHaise" Cc: "Daniel Phillips" ; "Rik van Riel" ; ; Sent: Saturday, August 04, 2001 2:37 AM Subject: Re: [RFC][DATA] re "ongoing vm suckage" > > Well, I've made a 2.4.8-pre4. > > This one has marcelo's zone fixes, and my request suggestions. I'm writing > email right now with the 8GB write in the background, and unpacked and > patched a kernel. It's certainly not _fast_, but it's not too painful to > use either. The 8GB file took 7:25 to write (including the sync), which > averages out to 18+MB/s. Which is, as far as I can tell, about the best I > can get on this 5400RPM 80GB drive with the current IDE driver (the > experimental IDE driver is supposed to do better, but that's not for > 2.4.x) > -- 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/