From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40B0Qh4tyVzF2HN for ; Wed, 28 Mar 2018 18:49:46 +1100 (AEDT) Received: from pps.filterd (m0098421.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w2S7YLf3018698 for ; Wed, 28 Mar 2018 03:49:44 -0400 Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) by mx0a-001b2d01.pphosted.com with ESMTP id 2h06e29w9h-1 (version=TLSv1.2 cipher=AES256-SHA256 bits=256 verify=NOT) for ; Wed, 28 Mar 2018 03:49:42 -0400 Received: from localhost by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 28 Mar 2018 08:49:40 +0100 Subject: Re: [PATCH v9 01/24] mm: Introduce CONFIG_SPECULATIVE_PAGE_FAULT To: David Rientjes , Thomas Gleixner Cc: paulmck@linux.vnet.ibm.com, peterz@infradead.org, akpm@linux-foundation.org, kirill@shutemov.name, ak@linux.intel.com, mhocko@kernel.org, dave@stgolabs.net, jack@suse.cz, Matthew Wilcox , benh@kernel.crashing.org, mpe@ellerman.id.au, paulus@samba.org, Ingo Molnar , hpa@zytor.com, Will Deacon , Sergey Senozhatsky , Andrea Arcangeli , Alexei Starovoitov , kemi.wang@intel.com, sergey.senozhatsky.work@gmail.com, Daniel Jordan , linux-kernel@vger.kernel.org, linux-mm@kvack.org, haren@linux.vnet.ibm.com, khandual@linux.vnet.ibm.com, npiggin@gmail.com, bsingharora@gmail.com, Tim Chen , linuxppc-dev@lists.ozlabs.org, x86@kernel.org References: <1520963994-28477-1-git-send-email-ldufour@linux.vnet.ibm.com> <1520963994-28477-2-git-send-email-ldufour@linux.vnet.ibm.com> From: Laurent Dufour Date: Wed, 28 Mar 2018 09:49:29 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Message-Id: <32c80b6a-28c6-bf63-ed7b-6a042ae18e8f@linux.vnet.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi David, Thanks a lot for your deep review on this series. On 25/03/2018 23:50, David Rientjes wrote: > On Tue, 13 Mar 2018, Laurent Dufour wrote: > >> This configuration variable will be used to build the code needed to >> handle speculative page fault. >> >> By default it is turned off, and activated depending on architecture >> support. >> >> Suggested-by: Thomas Gleixner >> Signed-off-by: Laurent Dufour >> --- >> mm/Kconfig | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/mm/Kconfig b/mm/Kconfig >> index abefa573bcd8..07c566c88faf 100644 >> --- a/mm/Kconfig >> +++ b/mm/Kconfig >> @@ -759,3 +759,6 @@ config GUP_BENCHMARK >> performance of get_user_pages_fast(). >> >> See tools/testing/selftests/vm/gup_benchmark.c >> + >> +config SPECULATIVE_PAGE_FAULT >> + bool > > Should this be configurable even if the arch supports it? Actually, this is not configurable unless by manually editing the .config file. I made it this way on the Thomas's request : https://lkml.org/lkml/2018/1/15/969 That sounds to be the smarter way to achieve that, isn't it ? Laurent.