From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id B6AD96B033C for ; Wed, 24 May 2017 07:20:34 -0400 (EDT) Received: by mail-pf0-f200.google.com with SMTP id n75so192164852pfh.0 for ; Wed, 24 May 2017 04:20:34 -0700 (PDT) Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com. [148.163.156.1]) by mx.google.com with ESMTPS id l192si23841510pga.13.2017.05.24.04.20.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 24 May 2017 04:20:34 -0700 (PDT) Received: from pps.filterd (m0098394.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4OBFPhN056184 for ; Wed, 24 May 2017 07:20:33 -0400 Received: from e06smtp11.uk.ibm.com (e06smtp11.uk.ibm.com [195.75.94.107]) by mx0a-001b2d01.pphosted.com with ESMTP id 2an1m13k45-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 24 May 2017 07:20:33 -0400 Received: from localhost by e06smtp11.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 24 May 2017 12:20:30 +0100 From: Laurent Dufour Subject: [RFC v2 10/10] mm: Introduce CONFIG_MEM_RANGE_LOCK Date: Wed, 24 May 2017 13:20:01 +0200 In-Reply-To: <1495624801-8063-1-git-send-email-ldufour@linux.vnet.ibm.com> References: <1495624801-8063-1-git-send-email-ldufour@linux.vnet.ibm.com> Message-Id: <1495624801-8063-11-git-send-email-ldufour@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-mm@kvack.org Cc: Davidlohr Bueso , akpm@linux-foundation.org, Jan Kara , "Kirill A . Shutemov" , Michal Hocko , Peter Zijlstra , Mel Gorman , Andi Kleen , haren@linux.vnet.ibm.com, aneesh.kumar@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, paulmck@linux.vnet.ibm.com, linux-kernel@vger.kernel.org A new configuration variable is introduced to activate the use of range lock instead of semaphore to protect per process memory layout. This range lock is replacing the use of a semaphore for mmap_sem. Currently only available for X86_64 and PPC64 architectures. By default this option is turned off and requires the EXPERT mode since it is not yet complete. Signed-off-by: Laurent Dufour --- mm/Kconfig | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/Kconfig b/mm/Kconfig index beb7a455915d..955d9a735a49 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -309,6 +309,18 @@ config NEED_BOUNCE_POOL bool default y if TILE && USB_OHCI_HCD +config MEM_RANGE_LOCK + bool "Use range lock for process's memory layout" + default n + depends on EXPERT + depends on MMU + depends on X86_64 || PPC64 + help + Use range lock instead of traditional semaphore to protect per + process memory layout. This is required when dealing with massive + threaded process on very large system (more than 80 cpu threads). + If unsure say n. + config NR_QUICK int depends on QUICKLIST -- 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org