X-Recipient: archive-cygwin@delorie.com X-Spam-Check-By: sourceware.org To: cygwin@cygwin.com From: Matthew Woehlke Subject: Re: interpretation of %CPU in 'procps' output for multi-cpu & hyperthreading Date: Thu, 11 Oct 2007 10:05:03 -0500 Lines: 21 Message-ID: References: <200710111458.l9BEwBoo022386@tigris.pounder.sol.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.1.6) Gecko/20070728 Thunderbird/2.0.0.6 Mnenhy/0.7.5.0 In-Reply-To: <200710111458.l9BEwBoo022386@tigris.pounder.sol.net> X-IsSubscribed: yes Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Tom Rodman wrote: > I would guess gzip must run on exactly 1 cpu, at any given time. > If so, then at most, gzip could use 1/8 of the total > CPU resources or 12.5%, as reported by windows task manager, > right? So procps is reporting the percent of the current virtual CPU, > that gzip is using, right? > > Notice that 'pslist' (from SysInternals) shows gzip, using > 9%; 9/12.5 * 100 = 72% of 1 virtual CPU. > > Is there a way to prove that a given process with more than 1 thread, > is still restricted to just one CPU? Unless you have manually set affinity, why would this be true? More likely, only one thread is actually doing anything. -- Matthew If a signature is not read by anyone, does it make a sound? -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/