From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xavier Bru Date: Thu, 17 Feb 2005 11:05:00 +0000 Subject: Re: Allow to change SD_NODES_PER_DOMAIN at configuration or boot Message-Id: <42147A5C.30007@bull.net> MIME-Version: 1 Content-Type: multipart/mixed; boundary="------------050708080604060803070600" List-Id: References: <42138013.3060909@bull.net> In-Reply-To: <42138013.3060909@bull.net> To: linux-ia64@vger.kernel.org This is a multi-part message in MIME format. --------------050708080604060803070600 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1"; format="flowed" Nick Piggin wrote: >Right. It may make more sense to have the setup based on some >maximum distance between nodes. Eg. all nodes less than distance >10 away from node0 are to be in node0's first level NUMA domain >(the next level is always global, IIRC). > >Then you would still need some configuration option, but it would >appear to be a more useful metric to use. > > =20 > Hello Nick & all, Do you mean that there should ever be only one NUMA sched-domain level ? On a 2x4x4 cpus machine, we could in theory have SD_NODES_PER_DOMAIN=3D4, = thus providing a 2 level NUMA sched-domain (domain 0 spans 4 cpus,=20 domain 1 spans 16, domain 2 is global and spans 32). But it is true that this configuration does not show evident performance=20 gains upon SD_NODES_PER_DOMAIN=3D8 (domain 0 spans 4 cpus, domain 1 is=20 global and spans 32), at least on parallel compilation of the kernel. Providing SD_NODES_PER_DOMAIN as a boot parameter was also intended to=20 choose between a multilevel sched-domains or not. --=20 Sinc=E8res salutations. --------------050708080604060803070600 Content-Transfer-Encoding: 7bit Content-Type: text/x-vcard; charset=utf-8; name="xavier.bru.vcf" Content-Disposition: attachment; filename="xavier.bru.vcf" begin:vcard fn:Xavier Bru n:Bru;Xavier adr:;;1 rue de Provence, BP 208;Echirolles;;38432 Cedex;France email;internet:Xavier.Bru@bull.net title:BULL/DT/Open Software/linux/ia64 tel;work:+33 (0)4 76 29 77 45 tel;fax:+33 (0)4 76 29 77 70 x-mozilla-html:TRUE url:http://www-frec.bull.fr version:2.1 end:vcard --------------050708080604060803070600--