Date: Fri, 31 Jan 2003 16:41:02 -0200 From: "Daniel C. Sobral" <dcs@tcoip.com.br> To: Matthew Dillon <dillon@apollo.backplane.com> Cc: Trish Lynch <trish@bsdunix.net>, freebsd-current@FreeBSD.ORG Subject: Re: Hyperthreading and machdep.cpu_idle_hlt Message-ID: <3E3AC33E.9060204@tcoip.com.br> In-Reply-To: <200301311824.h0VIOtmF095380@apollo.backplane.com> References: <20030131125804.E1357-100000@femme> <200301311824.h0VIOtmF095380@apollo.backplane.com>
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Matthew Dillon wrote: > :So, at the request of bmilekic, I ran netpipe on a hyperthreading box (non > :hyperthreading, I'll do when I can turn it off in BIOS next time I'm down > :there) > :... > : > :The results are here: > : > :http://bsdunix.net/performance > : > :all information on what command line options I used is in there. > : > :the difference with it on is pretty substantial, might be worth noting in > :tuning(7) > : > :-Trish > : > :-- > :Trish Lynch trish@bsdunix.net > > Those results are indeed quite substantial. Before you modify > tuning(7), though, lets wait a bit to see if anyone comes up with a > fix to the performance issue when idle_hlt is turned off. In particular > I would like to try using a per-cpu global test in the idle loop that > avoids doing any locked bus cycles. > > Unfortunately I am not sure if I have any hyperthreading capable boxes. > My primary machine is a pentium 4 but it is running -stable. > > Timecounter "i8254" frequency 1193182 Hz > Timecounter "TSC" frequency 1296069572 Hz > CPU: Pentium 4 (1296.07-MHz 686-class CPU) > Origin = "GenuineIntel" Id = 0xf07 Stepping = 7 > Features=0x3febf9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,P > AT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,<b28>,ACC> > > It has HTT set but it's only a 1.2GHz box and I heard somewhere that only > 2+ GHz P4's had hyperthreading. I noticed some MFCs to stable that > suggested hyperthreading support but I do not know if full hyperthreading > support has been MFCd yet or is intended to be MFCd to -stable. AFAIK, full hyperthreading support, as it is, has been merged to -stable. It consists of a patch to recognize the virtual CPUs, so they will be dealt with like any SMP system, as long as HTT is enabled on the BIOS. -- Daniel C. Sobral (8-DCS) Gerencia de Operacoes Divisao de Comunicacao de Dados Coordenacao de Seguranca TCO Fones: 55-61-313-7654/Cel: 55-61-9618-0904 E-mail: Daniel.Capo@tco.net.br Daniel.Sobral@tcoip.com.br dcs@tcoip.com.br Outros: dcs@newsguy.com dcs@freebsd.org capo@notorious.bsdconspiracy.net In 1914, the first crossword puzzle was printed in a newspaper. The creator received $4000 down ... and $3000 across. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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