From owner-freebsd-smp Fri Jun 11 21: 7:24 1999 Delivered-To: freebsd-smp@freebsd.org Received: from ivory.lm.com (ivory.telerama.com [205.201.1.20]) by hub.freebsd.org (Postfix) with ESMTP id 31E0C14EA8; Fri, 11 Jun 1999 21:07:17 -0700 (PDT) (envelope-from evs@telerama.com) Received: from mvehpc (d13-23.dyn.telerama.com [205.201.41.215]) by ivory.lm.com (8.8.5/8.6.12) with SMTP id AAA29650; Sat, 12 Jun 1999 00:07:10 -0400 (EDT) Message-ID: <09f401beb488$bb612390$6f27abcd@mvehpc.evs.slip.lm.com> Reply-To: "Mikhail V. Evstiounin" From: "Mikhail V. Evstiounin" To: , "David E. Cross" Cc: , Subject: Re: High syscall overhead? Date: Sat, 12 Jun 1999 00:04:53 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="koi8-r" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.5 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-freebsd-smp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org I have installed 3.0-RELEASE FreeBSD on AMD K6, 233MHz, 128MB, ABit Motherboard, not overclocked/ Ran this program, got the following results: 5.2u 8.5s 0:14.02 98.3% 5+171k 0+0io 0pf+0w. :-( -----Original Message----- From: Chris Costello To: David E. Cross Cc: freebsd-hackers@FreeBSD.ORG ; freebsd-smp@FreeBSD.ORG Date: Friday, June 11, 1999 11:01 AM Subject: Re: High syscall overhead? >On Fri, Jun 11, 1999, David E. Cross wrote: >> Just doing some performance testing and I noticed something rather >> disturbing.... >> >> Here is the test program: >> int main (void) >> { >> int count=0; >> for(count=0;count <10000000;++count) >> getppid(); >> >> return 0; >> } >> >> The time on linux for this program is ~5 seconds (linux "time" reports 3.x, but >> a wall clock clearly shows 5.x, go fig). FreeBSD reports 18.x seconds?!. I >> have a dual processor system and decided to parallel run them... it took >> 52!?! seconds, linux on the same was again about 5. Looking through the >> exception.s it appears that on entry to the kernel an MP lock is obtained... >> I thought we had splX(); to protect concurancy in the kernel. > >('sc' being the program above, compiled without optimization, > just with cc -o sc sc.c) >$ time ./sc > 10.04s real 3.89s user 5.64s system > > I counted between around 9 and a half to 10 and a half seconds >on my wall clock (trusty old GE, same model they have in public >schools). > >Copyright (c) 1992-1999 The FreeBSD Project. >Copyright (c) 1982, 1986, 1989, 1991, 1993 > The Regents of the University of California. All rights reserved. >FreeBSD 4.0-CURRENT #4: Sun May 30 04:22:23 CDT 1999 > root@holly.dyndns.org:/usr/src/sys/compile/Holly >Timecounter "i8254" frequency 1193182 Hz >CPU: AMD-K6(tm) 3D processor (350.80-MHz 586-class CPU) > Origin = "AuthenticAMD" Id = 0x580 Stepping=0 > Features=0x8001bf >real memory = 67108864 (65536K bytes) >sio0: system console >avail memory = 62267392 (60808K bytes) > > SMP specific bug, perhaps? > >> >> I am just curious what's the story with this. On some of my other tests it is >> clear that FreeBSD is handling concurancy much better than linux (by an equal >> factor actually, and on "real" tasks like real I/O handling). >> >> -- >> David Cross | email: crossd@cs.rpi.edu >> Systems Administrator/Research Programmer | Web: http://www.cs.rpi.edu/~crossd >> Rensselaer Polytechnic Institute, | Ph: 518.276.2860 >> Department of Computer Science | Fax: 518.276.4033 >> I speak only for myself. | WinNT:Linux::Linux:FreeBSD >> >> >> To Unsubscribe: send mail to majordomo@FreeBSD.org >> with "unsubscribe freebsd-hackers" in the body of the message > >-- >Chris Costello >This message transmitted on 100% recycled electrons. > > >To Unsubscribe: send mail to majordomo@FreeBSD.org >with "unsubscribe freebsd-smp" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message