From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261281AbVG1Dpv (ORCPT ); Wed, 27 Jul 2005 23:45:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261283AbVG1Dpv (ORCPT ); Wed, 27 Jul 2005 23:45:51 -0400 Received: from ms-smtp-04.nyroc.rr.com ([24.24.2.58]:1514 "EHLO ms-smtp-04.nyroc.rr.com") by vger.kernel.org with ESMTP id S261281AbVG1Dps (ORCPT ); Wed, 27 Jul 2005 23:45:48 -0400 Subject: Re: [RFC][PATCH] Make MAX_RT_PRIO and MAX_USER_RT_PRIO configurable From: Steven Rostedt To: Daniel Walker Cc: LKML , Linus Torvalds , Andrew Morton , Ingo Molnar In-Reply-To: <1122521538.29823.177.camel@localhost.localdomain> References: <1122473595.29823.60.camel@localhost.localdomain> <1122512420.5014.6.camel@c-67-188-6-232.hsd1.ca.comcast.net> <1122513928.29823.150.camel@localhost.localdomain> <1122519999.29823.165.camel@localhost.localdomain> <1122521538.29823.177.camel@localhost.localdomain> Content-Type: text/plain Organization: Kihon Technologies Date: Wed, 27 Jul 2005 23:45:28 -0400 Message-Id: <1122522328.29823.186.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2005-07-27 at 23:32 -0400, Steven Rostedt wrote: > New benchmarks with my own formula. > Take two: I ran this on my laptop (IBM ThinkPad G41 with an 3.3GHz Pentium 4 HT processor, yeah yeah, no battery life :-). But this has an older compiler. $ gcc -v Reading specs from /usr/lib/gcc-lib/i486-linux-gnu/3.3.6/specs Configured with: ../src/configure -v --enable-languages=c,c ++,java,f77,pascal,objc,ada,treelang --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-gxx-include-dir=/usr/include/c++/3.3 --enable-shared --enable-__cxa_atexit --with-system-zlib --enable-nls --without-included-gettext --enable-clocale=gnu --enable-debug --enable-java-gc=boehm --enable-java-awt=xlib --enable-objc-gc i486-linux-gnu Thread model: posix gcc version 3.3.6 (Debian 1:3.3.6-7) Here's the results on it: compiled again with "gcc -O2 -o ffb ffb.c" /* comments embedded */ sched=128 ffb=160 my=160 /* this is a 3.3GHz so clocks look good */ clock speed = 00000000:c5e54f4c 3320139596 ticks per second sched=159 ffb=159 my=159 last bit set generic ffb: 00000000:0a25b1d0 /* Hmm, all generic ffb is even slower? do I blame gcc or Intel? */ time: 0.051275712us sched ffb: 00000000:0023ae21 /* double Hmm, Ingo's is faster !? */ time: 0.000704289us my ffb: 00000000:019c458d /* look at this, mine is the same. Are the three bears coming around soon :-) */ time: 0.008137802us sched=0 ffb=0 my=0 first bit set generic ffb: 00000000:09766c3c time: 0.047816034us sched ffb: 00000000:0023c79f time: 0.000706254us my ffb: 00000000:005a8758 time: 0.001786939us OK, still looks like the generic ffb can be changed. Unless I'm missing something, this shows that I probably should be sending in a patch now to replace the find_first_bit. Ingo's sched_find_first_bit is still the winner, but that is customed to the scheduler, until we need a configurable priority. What do you think? -- Steve