From owner-freebsd-performance@FreeBSD.ORG Fri Jul 8 00:19:10 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 B452D106564A for ; Fri, 8 Jul 2011 00:19:10 +0000 (UTC) (envelope-from cswiger@mac.com) Received: from asmtpout029.mac.com (asmtpout029.mac.com [17.148.16.104]) by mx1.freebsd.org (Postfix) with ESMTP id 921D18FC1D for ; Fri, 8 Jul 2011 00:19:10 +0000 (UTC) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; CHARSET=US-ASCII Received: from cswiger1.apple.com ([17.209.4.71]) by asmtp029.mac.com (Oracle Communications Messaging Exchange Server 7u4-20.01 64bit (built Nov 21 2010)) with ESMTPSA id <0LNZ00M56KMIYE60@asmtp029.mac.com>; Thu, 07 Jul 2011 16:15:55 -0700 (PDT) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.4.6813,1.0.211,0.0.0000 definitions=2011-07-07_10:2011-07-07, 2011-07-07, 1970-01-01 signatures=0 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 spamscore=0 ipscore=0 suspectscore=0 phishscore=0 bulkscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx engine=6.0.2-1012030000 definitions=main-1107070220 From: Chuck Swiger In-reply-to: <4E163856.2050300@zedat.fu-berlin.de> Date: Thu, 07 Jul 2011 16:15:54 -0700 Message-id: <5C3302CF-8EE7-489E-8D31-624DA1637B73@mac.com> 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> <4E163856.2050300@zedat.fu-berlin.de> To: "Hartmann, O." X-Mailer: Apple Mail (2.1084) Cc: freebsd-performance@freebsd.org, FreeBSD current 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: Fri, 08 Jul 2011 00:19:10 -0000 On Jul 7, 2011, at 3:51 PM, Hartmann, O. wrote: > This is quibbling. On heavy loads on networ, disk et cetera, isn't there always and also a CPU bound load? No. Properly written software blocks when waiting on network or disk I/O, and doesn't sit there spinning in a busy-wait consuming CPU until it actually gets more work to do. See select(2), kqueue(2), and friends. Regards, -- -Chuck