Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758256AbXENGbU (ORCPT ); Mon, 14 May 2007 02:31:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758794AbXENGbE (ORCPT ); Mon, 14 May 2007 02:31:04 -0400 Received: from imx12.toshiba.co.jp ([61.202.160.132]:52938 "EHLO imx12.toshiba.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759224AbXENGbD (ORCPT ); Mon, 14 May 2007 02:31:03 -0400 Date: Mon, 14 May 2007 15:30:45 +0900 Message-ID: From: Tsutomu OWA To: linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Cc: mingo@elte.hu, tglx@linutronix.de Subject: Re: [patch 0/4] powerpc 2.6.21-rt1: reduce scheduling latency by changing tlb flush size In-Reply-To: References: User-Agent: Wanderlust/2.8.1 (Something) Emacs/20.7 Mule/4.0 (HANANOEN) Organization: Software Engineering Center, TOSHIBA. MIME-Version: 1.0 (generated by SEMI 1.14.4 - "Hosorogi") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1222 Lines: 32 To reduce scheduling latecy by changing tlb flush size to 1. Since tlb flush on Celleb is done by calling (an) expensive hypervisor call(s), it takes a long time to flush tlbs and causes scheduing latency. As I don't know how long it takes on other platforms, it would be better to enclose it within #ifdef CONFIG_PPC_CELLEB. Signed-off-by: Tsutomu OWA -- owa diff -rup linux-2.6.21-rt1/include/asm-powerpc/tlbflush.h rt/include/asm-powerpc/tlbflush.h --- linux-2.6.21-rt1/include/asm-powerpc/tlbflush.h 2007-04-26 12:08:32.000000000 +0900 +++ rt/include/asm-powerpc/tlbflush.h 2007-05-07 14:23:50.000000000 +0900 @@ -25,7 +25,11 @@ struct mm_struct; #include #include +#ifdef CONFIG_PREEMPT_RT +#define PPC64_TLB_BATCH_NR 1 /* Since tlb flush takes long time, reduce it to 1 when RT */ +#else #define PPC64_TLB_BATCH_NR 192 +#endif /* CONFIG_PREEMPT_RT */ struct ppc64_tlb_batch { unsigned long index; - 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/