From mboxrd@z Thu Jan 1 00:00:00 1970 From: alex.shi@intel.com (Alex Shi) Date: Fri, 14 Dec 2012 15:57:19 +0800 Subject: [RFC PATCH v2 3/6] sched: pack small tasks In-Reply-To: <1355471146.7641.13.camel@marge.simpson.net> References: <1355319092-30980-1-git-send-email-vincent.guittot@linaro.org> <1355319092-30980-4-git-send-email-vincent.guittot@linaro.org> <50C93AC1.1060202@intel.com> <50C9E552.1010600@intel.com> <1355460356.5777.12.camel@marge.simpson.net> <50CAC905.9070100@intel.com> <1355471146.7641.13.camel@marge.simpson.net> Message-ID: <50CADBDF.60305@intel.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 12/14/2012 03:45 PM, Mike Galbraith wrote: > On Fri, 2012-12-14 at 14:36 +0800, Alex Shi wrote: >> On 12/14/2012 12:45 PM, Mike Galbraith wrote: >>>>> Do you have further ideas for buddy cpu on such example? >>>>>>> >>>>>>> Which kind of sched_domain configuration have you for such system ? >>>>>>> and how many sched_domain level have you ? >>>>> >>>>> it is general X86 domain configuration. with 4 levels, >>>>> sibling/core/cpu/numa. >>> CPU is a bug that slipped into domain degeneration. You should have >>> SIBLING/MC/NUMA (chasing that down is on todo). >> >> Maybe. >> the CPU/NUMA is different on domain flags, CPU has SD_PREFER_SIBLING. > > What I noticed during (an unrelated) bisection on a 40 core box was > domains going from so.. > > 3.4.0-bisect (virgin) > [ 5.056214] CPU0 attaching sched-domain: > [ 5.065009] domain 0: span 0,32 level SIBLING > [ 5.075011] groups: 0 (cpu_power = 589) 32 (cpu_power = 589) > [ 5.088381] domain 1: span 0,4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76 level MC > [ 5.107669] groups: 0,32 (cpu_power = 1178) 4,36 (cpu_power = 1178) 8,40 (cpu_power = 1178) 12,44 (cpu_power = 1178) > 16,48 (cpu_power = 1177) 20,52 (cpu_power = 1178) 24,56 (cpu_power = 1177) 28,60 (cpu_power = 1177) > 64,72 (cpu_power = 1176) 68,76 (cpu_power = 1176) > [ 5.162115] domain 2: span 0-79 level NODE > [ 5.171927] groups: 0,4,8,12,16,20,24,28,32,36,40,44,48,52,56,60,64,68,72,76 (cpu_power = 11773) > 1,5,9,13,17,21,25,29,33,37,41,45,49,53,57,61,65,69,73,77 (cpu_power = 11772) > 2,6,10,14,18,22,26,30,34,38,42,46,50,54,58,62,66,70,74,78 (cpu_power = 11773) > 3,7,11,15,19,23,27,31,35,39,43,47,51,55,59,63,67,71,75,79 (cpu_power = 11770) > > ..to so, which looks a little bent. CPU and MC have identical spans, so > CPU should have gone away, as it used to do. > better to remove one, and believe you can make it. :)