Date: Sat, 13 Jun 2009 13:43:04 -0500 From: Dan Nelson <dnelson@allantgroup.com> To: Yuri <yuri@rawbw.com> Cc: freebsd-hackers@freebsd.org Subject: Re: top shows that multithreaded program uses 19623.14% CPU Message-ID: <20090613184303.GK56070@dan.emsphone.com> In-Reply-To: <4A33544C.1070902@rawbw.com> References: <4A33544C.1070902@rawbw.com>
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In the last episode (Jun 13), Yuri said: > I ran then program with 1500 threads and in top it looked the this: > > PID USERNAME THR PRI NICE SIZE RES STATE C TIME CPU COMMAND > 20382 yuri 1500 99 0 641M 462M umtxn 0 0:00 19623.14% quicksort > <skipped further> > > Where can I read how CPU column is calculated? > > Some time ago I saw another weird fenomenon when CPU column: 5% CPU load > for the pocess that just cycles in CPU. Top doesn't seem to show the right %CPU at all for threaded apps unless you hit H to view each thread individually. Then you get accurate numbers (but you have to manually sum up the threads usage if you want to see the total %CPU for an entire process). -- Dan Nelson dnelson@allantgroup.com
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