From owner-freebsd-performance@FreeBSD.ORG Thu Jul 7 22:51:04 2011 Return-Path: Delivered-To: freebsd-performance@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4850C106564A; Thu, 7 Jul 2011 22:51:04 +0000 (UTC) (envelope-from ohartman@zedat.fu-berlin.de) Received: from outpost1.zedat.fu-berlin.de (outpost1.zedat.fu-berlin.de [130.133.4.66]) by mx1.freebsd.org (Postfix) with ESMTP id EC6AB8FC14; Thu, 7 Jul 2011 22:51:03 +0000 (UTC) Received: from inpost2.zedat.fu-berlin.de ([130.133.4.69]) by outpost1.zedat.fu-berlin.de (Exim 4.69) with esmtp (envelope-from ) id <1QexPS-0003Jx-Pk>; Fri, 08 Jul 2011 00:51:02 +0200 Received: from e178023242.adsl.alicedsl.de ([85.178.23.242] helo=thor.walstatt.dyndns.org) by inpost2.zedat.fu-berlin.de (Exim 4.69) with esmtpsa (envelope-from ) id <1QexPS-0002J5-MI>; Fri, 08 Jul 2011 00:51:02 +0200 Message-ID: <4E163856.2050300@zedat.fu-berlin.de> Date: Fri, 08 Jul 2011 00:51:02 +0200 From: "Hartmann, O." User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:5.0) Gecko/20110630 Thunderbird/5.0 MIME-Version: 1.0 To: Andriy Gapon References: <4E1421D9.7080808@zedat.fu-berlin.de> <4E147F54.40908@zedat.fu-berlin.de> <20110706162811.GA68436@troutmask.apl.washington.edu> <20110706193636.GA69550@troutmask.apl.washington.edu> <4E14CCE5.4050906@zedat.fu-berlin.de> <20110707015151.GB71966@troutmask.apl.washington.edu> <20110707031151.GA72452@troutmask.apl.washington.edu> <4E155A84.1010100@FreeBSD.org> In-Reply-To: <4E155A84.1010100@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: 85.178.23.242 Cc: Adrian Chadd , Steve Kargl , arrowdodger <6yearold@gmail.com>, FreeBSD Current , Arnaud Lacombe , "freebsd-performance@freebsd.org" Subject: Re: Heavy I/O blocks FreeBSD box for several seconds X-BeenThere: freebsd-performance@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Performance/tuning List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Jul 2011 22:51:04 -0000 On 07/07/11 09:04, Andriy Gapon wrote: > on 07/07/2011 06:11 Steve Kargl said the following: >> Unfortunately, I have neither the brain capacity and time nor >> the money to fix the issue. To solve OP's problem in the >> short, the simplest solution may be to switch to 4BSD. Let's >> face, ULE is not a silver bullet. > I think that piling up different problems into a single discussion, even if they > involve a common component (to a certain degree), is not going to help anybody. > If I have read this thread correctly (and taking the subject line as a witness) > the OP had a problem with heavy I/O activity screwing up interactivity. I think > that it's not the same problem as sub-optimal performance of heavy CPU-bound > load, which is what you reported if I am not mistaken. > This is quibbling. On heavy loads on networ, disk et cetera, isn't there always and also a CPU bound load? Whenever this problem came up, it was brought down by force. Yes, I reported due to the obvious fact that this essential problem involves usability of several workstations. It get more obvious when FreeBSD is used with a GUI. But I also realized, as I reported(!), problems on a headless server, even with several tunings, performed slowly and with increasing numbers over time as recommended here (for instance, kern.sched.preempt_thresh=224 or up to kern.sched.preempt_thresh=512, with little effect). Where, if not here, should such problems be discussed? If we open for each dedicated micro-problem a separate thread, we would never gather that many problems which seem to be related to one single well known 'sweet spot'.