From owner-freebsd-performance@FreeBSD.ORG Fri Oct 31 08:12:59 2008 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 E7AF61065674 for ; Fri, 31 Oct 2008 08:12:59 +0000 (UTC) (envelope-from prvs=julian=183d0fe36@elischer.org) Received: from smtp-outbound.ironport.com (smtp-outbound.ironport.com [63.251.108.112]) by mx1.freebsd.org (Postfix) with ESMTP id D70048FC18 for ; Fri, 31 Oct 2008 08:12:59 +0000 (UTC) (envelope-from prvs=julian=183d0fe36@elischer.org) Received: from unknown (HELO julian-mac.elischer.org) ([10.251.60.128]) by smtp-outbound.ironport.com with ESMTP; 31 Oct 2008 00:44:18 -0700 Message-ID: <490AB750.9040505@elischer.org> Date: Fri, 31 Oct 2008 00:44:16 -0700 From: Julian Elischer User-Agent: Thunderbird 2.0.0.17 (Macintosh/20080914) MIME-Version: 1.0 To: Krassimir Slavchev References: <000001c93b0c$6195e6b0$2f096f0a@china.huawei.com> <490AB477.2080001@bulinfo.net> In-Reply-To: <490AB477.2080001@bulinfo.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-performance@freebsd.org, Sam Xia Subject: Re: 1. thread switching time? (Krassimir Slavchev) 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, 31 Oct 2008 08:13:00 -0000 Krassimir Slavchev wrote: > > Also, I am able to set HZ=100000 but the thread switching time is still > ~1ms. You must be talking about the time that a thread can run before it is pushed out by other threads? I know I've seem many x 10,000 context switches in some cases, i.e. look at very high interrupt rates etc. so I guess I'm not sure what you are measuring.. at one time the scheduling quantum was independent of Hz. I am not sure how true that is now..