Date: Tue, 20 Nov 2007 16:47:02 +0000 From: Tom Evans <tevans.uk@googlemail.com> To: Alexey Popov <lol@chistydom.ru> Cc: freebsd-stable@freebsd.org, Ivan Voras <ivoras@freebsd.org> Subject: Re: 2 x quad-core system is slower that 2 x dual core on FreeBSD Message-ID: <1195577222.82763.20.camel@localhost> In-Reply-To: <47430AE8.7050408@chistydom.ru> References: <4741905E.8050300@chistydom.ru> <fhs3s5$knj$1@ger.gmane.org> <47419AB3.5030008@chistydom.ru> <fhs7db$2es$1@ger.gmane.org> <4741B3DE.2000009@chistydom.ru> <fhsl0v$n85$1@ger.gmane.org> <47430AE8.7050408@chistydom.ru>
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--=-3EIiZa0Krddtsz1adeD/ Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2007-11-20 at 19:27 +0300, Alexey Popov wrote: > Hi. > <snip> > After that I rebuilt with SMP GENERIC kernel and put on that server 2=20 > times more requests that UP could handle. For the first time it worked=20 > good. Then I increased load to 2.5 times more than UP. Immediately=20 > Apache child count increased to MaxClients (24), most of them in RUN=20 > state, and %sys became greater than %user (see attach). I think after=20 > some threshold of load FreeBSD is paying more CPU time to the management=20 > of running processes than to run them. >=20 > Also I tried to halt CPUs by machdep.hlt_cpus sysctl, but in that case=20 > %sys in top was still much greater than %user. MaxClients of 24 seems very low for a 8 cpu box, running prefork MPM. On our quad CPU boxes, running custom apache modules, we use=20 MaxClients 70 MinSpareServers 5 MaxSpareServers 15 StartServers 20 Perhaps you are seeing high system load because the system is having to maintain a lot of queued connections. Certainly, our load remains in-between comfortable margins, except when heavily stressed. Tom --=-3EIiZa0Krddtsz1adeD/ Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (FreeBSD) iD8DBQBHQw+AlcRvFfyds/cRAk0PAKDCzGQHCCNT29eueBa8/xZeq+1XaQCgqmi8 eb9xKET6MT0hxDCA2IIvG0k= =ozz2 -----END PGP SIGNATURE----- --=-3EIiZa0Krddtsz1adeD/--
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