From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20110725023426.037449739@samba.org> Date: Mon, 25 Jul 2011 12:33:12 +1000 From: Anton Blanchard To: mingo@elte.hu, peterz@infradead.org, benh@kernel.crashing.org Subject: [PATCH 1/5] powerpc/numa: Enable SD_WAKE_AFFINE in node definition References: <20110725023311.175792493@samba.org> Cc: fenghua.yu@intel.com, tony.luck@intel.com, linux-kernel@vger.kernel.org, ralf@linux-mips.org, lethal@linux-sh.org, cmetcalf@tilera.com, linuxppc-dev@lists.ozlabs.org, davem@davemloft.net List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , When chasing a performance issue on ppc64, I noticed tasks communicating via a pipe would often end up on different nodes. It turns out SD_WAKE_AFFINE is not set in our node defition. Commit 9fcd18c9e63e (sched: re-tune balancing) enabled SD_WAKE_AFFINE in the node definition for x86 and we need a similar change for ppc64. I used lmbench lat_ctx and perf bench pipe to verify this fix. Each benchmark was run 10 times and the average taken. lmbench lat_ctx: before: 66565 ops/sec after: 204700 ops/sec 3.1x faster perf bench pipe: before: 5.6570 usecs after: 1.3470 usecs 4.2x faster Signed-off-by: Anton Blanchard --- Cc-ing arch maintainers who might need to look at their SD_NODE_INIT definitions Index: linux-2.6-work/arch/powerpc/include/asm/topology.h =================================================================== --- linux-2.6-work.orig/arch/powerpc/include/asm/topology.h 2011-07-18 16:24:55.639949552 +1000 +++ linux-2.6-work/arch/powerpc/include/asm/topology.h 2011-07-18 16:25:02.630074557 +1000 @@ -73,7 +73,7 @@ static inline int pcibus_to_node(struct | 1*SD_BALANCE_EXEC \ | 1*SD_BALANCE_FORK \ | 0*SD_BALANCE_WAKE \ - | 0*SD_WAKE_AFFINE \ + | 1*SD_WAKE_AFFINE \ | 0*SD_PREFER_LOCAL \ | 0*SD_SHARE_CPUPOWER \ | 0*SD_POWERSAVINGS_BALANCE \