From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261724AbUGQUuN (ORCPT ); Sat, 17 Jul 2004 16:50:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261763AbUGQUuN (ORCPT ); Sat, 17 Jul 2004 16:50:13 -0400 Received: from wblv-254-37.telkomadsl.co.za ([165.165.254.37]:53462 "EHLO gateway.lan") by vger.kernel.org with ESMTP id S261724AbUGQUuB (ORCPT ); Sat, 17 Jul 2004 16:50:01 -0400 Subject: Re: 2.6.8-rc1-np1 From: Martin Schlemmer Reply-To: Martin Schlemmer To: Nick Piggin Cc: Felipe Alfaro Solana , Linux Kernel Mailing Lists In-Reply-To: <40F8F0A6.8020003@yahoo.com.au> References: <40F8B7C5.9030201@yahoo.com.au> <1090053943.1828.4.camel@teapot.felipe-alfaro.com> <40F8F0A6.8020003@yahoo.com.au> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-8tKptaP9WoRArDBbiMPO" Message-Id: <1090097552.9380.10.camel@nosferatu.lan> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Sat, 17 Jul 2004 22:52:32 +0200 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --=-8tKptaP9WoRArDBbiMPO Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Sat, 2004-07-17 at 11:25, Nick Piggin wrote: > Felipe Alfaro Solana wrote: > > On Sat, 2004-07-17 at 15:23 +1000, Nick Piggin wrote: > >=20 > >=20 > >>Scheduler behaviour is generally pretty good now so I've increased the > >>timeslice size to see how far I can push it. Some workloads really dema= nd > >>small timeslices though, so I've added /proc/sys/kernel/base_timeslice. > >>If you have any problems with the default, please report it to me, and > >>check if lowering this value helps. > >=20 > >=20 > > On my 700Mhz Pentium III Mobile laptop, I feel that 256ms is too high > > for the system to keep interactive when a CPU hog is running. For >=20 > Yeah, it is probably a bit too large here too. A burst of activity > from X can cause xmms to skip slightly. Probably 128 or 64 would > be a decent default. >=20 Feels fine here on 3GHz P4 (HT system on i875 with dual channel memory, striped raid ST38013AS HDD's). xmms haven't skipped yet (X reniced to -10) and desktop switching is quick. First time typing might be a bit sluggish in gnome-terminal, but second/third char is fine, and vim seems to load fast enough. All this is with a 'make -j24' for kernel (yeah, not really that realistic, but thought I should give it a go) and make -j4 for xorg-x11 going. A few load values is: load average: 26.72, 15.99, 7.35 load average: 27.93, 19.48, 9.52 load average: 28.02, 19.64, 9.63 load average: 26.01, 19.36, 9.59 base_timeslice is 256 btw ... > > example, running "while true; do a=3D2; done" makes the system pretty > > sluggish with the default timeslice. This is noticeable while dragging > > windows around (the movement is jerky and doesn't feel smooth). > > Decreasing the timeslie to 50ms, or even better, 25ms, makes the system > > behave much much better, although it will decrease throughput > > considerably, I guess. > >=20 >=20 Cannot say I can really feel this test. That with 'make -j4' for X have load: load average: 2.74, 4.45, 5.98 where the last is still high from the make -j24. > It usually isn't too bad for desktops, but is more important on > systems with more CPUs and bigger caches. >=20 > On this dual P3 with 256K L2 cache, a make -j8 vmlinux uses > 162.16user 15.43system, ~150ctxsw/s with base_timeslice =3D 10000 > 163.88user 16.16system, ~300ctxsw/s with base_timeslice =3D 32 > 192.65user 17.27system, ~1300ctxsw/s with base_timeslice =3D 1 >=20 > So you come to the point of diminishing returns very quickly, and > 32 or even 16 or 8 are probably fine values for a desktop system > and worth the small cost for CPU intensive tasks. > - > To unsubscribe from this list: send the line "unsubscribe linux-kernel" i= n > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ --=20 Martin Schlemmer --=-8tKptaP9WoRArDBbiMPO Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (GNU/Linux) iD8DBQBA+ZGPqburzKaJYLYRAoh/AKCTkHNWoTbEPsM/afmY/C6+7EtbvwCdE1f6 BxiPBwdyCK6ekiSkmhXq7do= =AVn/ -----END PGP SIGNATURE----- --=-8tKptaP9WoRArDBbiMPO--