Date: Fri, 30 Nov 2007 12:07:11 +0300 From: Alexey Popov <lol@chistydom.ru> To: Kris Kennaway <kris@FreeBSD.org> Cc: Attilio Rao <attilio@freebsd.org>, freebsd-stable@freebsd.org Subject: Re: 2 x quad-core system is slower that 2 x dual core on FreeBSD Message-ID: <474FD2BF.606@chistydom.ru> In-Reply-To: <474F12AE.7050808@FreeBSD.org> References: <4741905E.8050300@chistydom.ru> <fhs3s5$knj$1@ger.gmane.org> <47419AB3.5030008@chistydom.ru> <fhs7hp$2es$2@ger.gmane.org> <4741A7DA.2050706@chistydom.ru> <4741DA15.9000308@FreeBSD.org> <47429DB8.7040504@chistydom.ru> <4742ADFE.40902@FreeBSD.org> <4742C46A.1060701@chistydom.ru> <47432F77.3030606@FreeBSD.org> <474339E9.4080301@FreeBSD.org> <4743629B.9090408@FreeBSD.org> <47456B71.5040205@chistydom.ru> <4745E5B3.6060200@FreeBSD.org> <47468165.5010906@chistydom.ru> <4746B21F.7050906@FreeBSD.org> <4746BD92.6000204@chistydom.ru> <474F12AE.7050808@FreeBSD.org>
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Hi Kris Kennaway wrote: > One more patch which may or may not help is: > > http://www.freebsd.org/~jhb/patches/namei_rwlock.patch > > (may also require porting since it was against an older version of > 7.0-CURRENT). When I have tested this in the past it was a performance > loss for reasons that I think I understand (basically, it is locally a > performance improvement for the name cache but also requires a fixed > lockmgr to avoid an overall performance loss), but I don't remember if I > tested it in conjunction with the lockmgr patch. This patch doesn't apply to 7-STABLE because /sys/kern/vfs_cache.c was changed significanly since rev. 1.108. I tried to patch it manually but don't know what to do with cache_lookup() changes. >>> There are patches you need to enable it on woodcrest. They are in my >>> p4 branch (kris-contention) but I don't have time right now to >>> extract them. >> I think it would be very useful because I can't see any other ways to >> profile FreeBSD on the modern many-cores machines. > > You can extract the changeset from my branch via > http://perforce.freebsd.org. Unfortunately I don't have time to do it > myself. I'll try it if it does not also need porting. With best regards, Alexey Popov
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