Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756549AbZDCC6o (ORCPT ); Thu, 2 Apr 2009 22:58:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752715AbZDCC6f (ORCPT ); Thu, 2 Apr 2009 22:58:35 -0400 Received: from yx-out-2324.google.com ([74.125.44.28]:4595 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752258AbZDCC6e convert rfc822-to-8bit (ORCPT ); Thu, 2 Apr 2009 22:58:34 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=tK221wexu01Xhqm22emF5CRJmGFpkcSgzTbWkG6LNZISS2AaVINOtSl7fJOJ2rW+VJ pQqvnztMKEsx8aKVxryqHHE1A5OKHn1yIpLhQ7AlIfpEIcBq/nmxWfOSW/hNFXWe5bm1 6aSOb3+VwTzvN5coHhtukqk9RoryalRS3k98c= MIME-Version: 1.0 In-Reply-To: <9b1675090904021928k5a9948f9l8d93b6cbd5531720@mail.gmail.com> References: <49CCCB0A.6070701@nokia.com> <9b1675090904021724t2fb0a671uc10d8e7bcba0bc5c@mail.gmail.com> <9b1675090904021728y35776377u327f2266d06e2f29@mail.gmail.com> <72dbd3150904021855v440f46a7oc21a7ed28fbfcb13@mail.gmail.com> <9b1675090904021905o7e0cec64lfe4a5372777908b6@mail.gmail.com> <72dbd3150904021919g5405ee40p100eacb085024941@mail.gmail.com> <9b1675090904021928k5a9948f9l8d93b6cbd5531720@mail.gmail.com> Date: Thu, 2 Apr 2009 19:58:17 -0700 Message-ID: <72dbd3150904021958q7795dc62keb54d1fbfaa6abc7@mail.gmail.com> Subject: Re: EXT4-ish "fixes" in UBIFS From: David Rees To: "Trenton D. Adams" Cc: Christian Kujau , Artem Bityutskiy , Linux Kernel Mailing List Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1981 Lines: 37 On Thu, Apr 2, 2009 at 7:28 PM, Trenton D. Adams wrote: > On Thu, Apr 2, 2009 at 8:19 PM, David Rees wrote: >> On Thu, Apr 2, 2009 at 7:05 PM, Trenton D. Adams wrote: >>> On Thu, Apr 2, 2009 at 7:55 PM, David Rees wrote: >>>> On Thu, Apr 2, 2009 at 5:28 PM, Trenton D. Adams wrote: >>> dirty_ratio and dirty_background never really had any affect for me. >>> I'll look into the other parameters. ?Waiting for the checkout again, >>> as I am currently under a heavy rsync load (*rolls eyes*). >> >> How low have you set them? ?Try setting them to 2 and 1 respectively. >> It cuts down fsync latencies by a significant amount in my experience. > > That's the odd thing, I was setting them to 2 and 1. ?I was just > looking at the 2.6.29 code, and it should have made a difference. ?I > don't know what version of the kernel I was using at the time. ?And, > I'm not sure if I had the 1M fsync tests in place at the time either, > to be sure about what I was testing. ?It could be that I wasn't being > very scientific about it at the time. ?Thanks though, that setting > makes a huge difference. Well, it depends on how much memory you have. Keep in mind that those are percentages - so if you have 2GB RAM, that's the same as setting it to 40MB and 20MB respectively - both are a lot larger than the 1M you were setting the dirty*bytes vm knobs to. I've got a problematic server with 8GB RAM. Even if set both to 1, that's 80MB and the crappy disks I have in it will often only write 10-20MB/s or less due to the seekiness of the workload. That means delays of 5-10 seconds worst case which isn't fun. -Dave -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/