From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755712Ab1CGRtq (ORCPT ); Mon, 7 Mar 2011 12:49:46 -0500 Received: from bombadil.infradead.org ([18.85.46.34]:43041 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755635Ab1CGRtm (ORCPT ); Mon, 7 Mar 2011 12:49:42 -0500 Message-Id: <20110307172206.762715755@chello.nl> User-Agent: quilt/0.48-1 Date: Mon, 07 Mar 2011 18:13:54 +0100 From: Peter Zijlstra To: Thomas Gleixner , Rik van Riel , Ingo Molnar , akpm@linux-foundation.org, Linus Torvalds Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, Benjamin Herrenschmidt , David Miller , Hugh Dickins , Mel Gorman , Nick Piggin , Peter Zijlstra , Russell King , Chris Metcalf , Martin Schwidefsky Subject: [RFC][PATCH 04/15] mm: Optimize fullmm TLB flushing References: <20110307171350.989666626@chello.nl> Content-Disposition: inline; filename=mmu_gather_fullmm.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This originated from s390 which does something similar and would allow s390 to use the generic TLB flushing code. The idea is to flush the mm wide cache and tlb a priory and not bother with multiple flushes if the batching isn't large enough. This can be safely done since there cannot be any concurrency on this mm, its either after the process died (exit) or in the middle of execve where the thread switched to the new mm. Cc: Martin Schwidefsky Signed-off-by: Peter Zijlstra --- include/asm-generic/tlb.h | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) Index: linux-2.6/include/asm-generic/tlb.h =================================================================== --- linux-2.6.orig/include/asm-generic/tlb.h +++ linux-2.6/include/asm-generic/tlb.h @@ -149,6 +149,11 @@ tlb_gather_mmu(struct mmu_gather *tlb, s #ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb->batch = NULL; #endif + + if (fullmm) { + flush_cache_mm(mm); + flush_tlb_mm(mm); + } } static inline void @@ -156,13 +161,15 @@ tlb_flush_mmu(struct mmu_gather *tlb) { struct mmu_gather_batch *batch; - if (!tlb->need_flush) - return; - tlb->need_flush = 0; - flush_tlb_mm(tlb->mm); + if (!tlb->fullmm && tlb->need_flush) { + tlb->need_flush = 0; + flush_tlb_mm(tlb->mm); + } + #ifdef CONFIG_HAVE_RCU_TABLE_FREE tlb_table_flush(tlb); #endif + if (tlb_fast_mode(tlb)) return;