Date: Tue, 22 Jan 2008 17:04:02 +0200 From: Stefan Lambrev <stefan.lambrev@moneybookers.com> To: =?UTF-8?B?RGFnLUVybGluZyBTbcO4cmdyYXY=?= <des@des.no> Cc: freebsd-hackers@FreeBSD.org Subject: Re: gettimeofday() in hping Message-ID: <479605E2.6070709@moneybookers.com> In-Reply-To: <86lk6i0vzk.fsf@ds4.des.no> References: <4795CC13.7080601@moneybookers.com> <868x2i3v8d.fsf@ds4.des.no> <864pd63v2h.fsf@ds4.des.no> <4795FE54.9090606@moneybookers.com> <86lk6i0vzk.fsf@ds4.des.no>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi, Dag-Erling Sm=C3=B8rgrav wrote: > Stefan Lambrev <stefan.lambrev@moneybookers.com> writes: > =20 >> I tested all different combination. The performance change is almost >> invisible (100-200KB/s), and can't be compared with the performance >> boost that TSC gain over ACPI-fast timecounter. Unfortunately TSC >> doesn't play nice with power saving modes. >> =20 > > This will vary greatly from machine to machine, depending on the exact > hardware and the ACPI BIOS. > > More modern machines have an HPET timer which is supposedly faster than= > ACPI yet more reliable than TSC. > > DES > =20 I do not have HEPT on the servers that I test, but simple test on my=20 laptop shows that hping can generate with ACPI-fast ~4MB/s traffic, 5MB/s with HPET and 8MB/s with TSC. I didn't check dummy time counter. Also I noticed that there is a kern.timecounter.tc.XXX.quality (read only= ). Can this be used to reduce quality and speed up performance? --=20 Best Wishes, Stefan Lambrev ICQ# 24134177
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?479605E2.6070709>