Date: Fri, 31 Oct 2008 09:32:07 +0200 From: Krassimir Slavchev <krassi@bulinfo.net> To: Sam Xia <xiazhongqi@huawei.com> Cc: freebsd-performance@freebsd.org Subject: Re: 1. thread switching time? (Krassimir Slavchev) Message-ID: <490AB477.2080001@bulinfo.net> In-Reply-To: <000001c93b0c$6195e6b0$2f096f0a@china.huawei.com> References: <000001c93b0c$6195e6b0$2f096f0a@china.huawei.com>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, Sam Xia wrote: > hi krassi, > > what kind of hardware are you using? Actually because of process/thread > scheduling mechanism, timing granulariy is coarse in FreeBSD(more than 10 > ms) dmesg: ... CPU: Intel(R) Core(TM)2 CPU E8400 @ 3.00GHz (3005.25-MHz 686-class CPU) ... Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000 acpi_timer0: <24-bit timer at 3.579545MHz> port 0x408-0x40b on acpi0 acpi_hpet0: <High Precision Event Timer> iomem 0xfed00000-0xfed003ff on acpi0 Timecounter "HPET" frequency 14318180 Hz quality 900 ... The hardware is fast enough! Also, I am able to set HZ=100000 but the thread switching time is still ~1ms. Best Regards > > S.X >> -----Original Message----- >> From: owner-freebsd-performance@freebsd.org >> [mailto:owner-freebsd-performance@freebsd.org] On Behalf Of >> freebsd-performance-request@freebsd.org >> Sent: Thursday, October 30, 2008 8:00 PM >> To: freebsd-performance@freebsd.org >> Subject: freebsd-performance Digest, Vol 68, Issue 4 > >> Message: 1 >> Date: Wed, 29 Oct 2008 17:28:36 +0200 >> From: Krassimir Slavchev <krassi@bulinfo.net> >> Subject: thread switching time? >> To: freebsd-performance@freebsd.org >> Message-ID: <49088124.9050809@bulinfo.net> >> Content-Type: text/plain; charset=ISO-8859-1 >> > Hello All, > > I am using FreeBSD 7 and would like to decrease the time of > switching between threads. This time seems to be 1ms and it > is impossible to make lower delays inside a thread, at least > using nanosleep(). > > Is it possible to decrease this time to 1us? > > > Best Regards >> >> ************************************************** >> > _______________________________________________ > freebsd-performance@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-performance > To unsubscribe, send any mail to "freebsd-performance-unsubscribe@freebsd.org" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQFJCrR3xJBWvpalMpkRAq8aAJ9F/n9mX94h46Rb4kHOBo9kDMUjzQCgmcZQ Yuum1rMnhaKICE+FKC6n294= =y2hp -----END PGP SIGNATURE-----
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