Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269527AbUJFXTS (ORCPT ); Wed, 6 Oct 2004 19:19:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269581AbUJFXQL (ORCPT ); Wed, 6 Oct 2004 19:16:11 -0400 Received: from fmr03.intel.com ([143.183.121.5]:19348 "EHLO hermes.sc.intel.com") by vger.kernel.org with ESMTP id S269629AbUJFXO2 (ORCPT ); Wed, 6 Oct 2004 19:14:28 -0400 Message-Id: <200410062313.i96NDo609923@unix-os.sc.intel.com> From: "Chen, Kenneth W" To: "'Andrew Morton'" Cc: , , Subject: RE: Default cache_hot_time value back to 10ms Date: Wed, 6 Oct 2004 16:14:06 -0700 X-Mailer: Microsoft Office Outlook, Build 11.0.5510 Thread-Index: AcSr5V0gOunJ4+3qRGSPbBFTyRMu4QAEetDA In-Reply-To: <20041006134317.03a22198.akpm@osdl.org> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2369 Lines: 62 Andrew Morton wrote on Wednesday, October 06, 2004 1:43 PM > "Chen, Kenneth W" wrote: > > > > Secondly, let me ask the question again from the first mail thread: this value > > *WAS* 10 ms for a long time, before the domain scheduler. What's so special > > about domain scheduler that all the sudden this parameter get changed to 2.5? > > So why on earth was it switched from 10 to 2.5 in the first place? > > Please resend the final patch. Here is a patch that revert default cache_hot_time value back to the equivalence of pre-domain scheduler, which determins task's cache affinity via architecture defined variable cache_decay_ticks. This is a mere request that we go back to what *was* before, *NOT* as a new scheduler tweak (Whatever tweak done for domain scheduler broke traditional/ industry recognized workload). As a side note, I'd like to get involved on future scheduler tuning experiments, we have fair amount of benchmark environments where we can validate things across various kind of workload, i.e., db, java, cpu, etc. Thanks. Signed-off-by: Ken Chen patch against 2.6.9-rc3: --- linux-2.6.9-rc3/kernel/sched.c.orig 2004-10-06 15:10:56.000000000 -0700 +++ linux-2.6.9-rc3/kernel/sched.c 2004-10-06 15:18:51.000000000 -0700 @@ -387,7 +387,7 @@ struct sched_domain { .max_interval = 4, \ .busy_factor = 64, \ .imbalance_pct = 125, \ - .cache_hot_time = (5*1000000/2), \ + .cache_hot_time = cache_decay_ticks*1000000,\ .cache_nice_tries = 1, \ .per_cpu_gain = 100, \ .flags = SD_BALANCE_NEWIDLE \ patch against 2.6.9-rc3-mm2: --- linux-2.6.9-rc3/include/linux/topology.h.orig 2004-10-06 15:32:48.000000000 -0700 +++ linux-2.6.9-rc3/include/linux/topology.h 2004-10-06 15:33:25.000000000 -0700 @@ -113,7 +113,7 @@ static inline int __next_node_with_cpus( .max_interval = 4, \ .busy_factor = 64, \ .imbalance_pct = 125, \ - .cache_hot_time = (5*1000/2), \ + .cache_hot_time = (cache_decay_ticks*1000),\ .cache_nice_tries = 1, \ .per_cpu_gain = 100, \ .flags = SD_LOAD_BALANCE \ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in 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/