From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 8CFA0280258 for ; Thu, 22 Dec 2016 17:12:36 -0500 (EST) Received: by mail-wm0-f71.google.com with SMTP id u144so38337873wmu.1 for ; Thu, 22 Dec 2016 14:12:36 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id o4si29579256wmb.73.2016.12.22.14.12.35 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 22 Dec 2016 14:12:35 -0800 (PST) From: Andreas Schwab Subject: Re: [PATCH] mm: pmd dirty emulation in page fault handler References: <1482364101-16204-1-git-send-email-minchan@kernel.org> <20161222081713.GA32480@node.shutemov.name> <20161222145203.GA18970@bbox> Date: Thu, 22 Dec 2016 23:12:32 +0100 In-Reply-To: <20161222145203.GA18970@bbox> (Minchan Kim's message of "Thu, 22 Dec 2016 23:52:03 +0900") Message-ID: <8737hftxyn.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain Sender: owner-linux-mm@kvack.org List-ID: To: Minchan Kim Cc: "Kirill A. Shutemov" , Andrew Morton , linux-mm@kvack.org, Jason Evans , "Kirill A . Shutemov" , Will Deacon , Catalin Marinas , linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, "[4.5+]" On Dez 22 2016, Minchan Kim wrote: > From b3ec95c0df91ad113525968a4a6b53030fd0b48d Mon Sep 17 00:00:00 2001 > From: Minchan Kim > Date: Thu, 22 Dec 2016 23:43:49 +0900 > Subject: [PATCH v2] mm: pmd dirty emulation in page fault handler > > Andreas reported [1] made a test in jemalloc hang in THP mode in arm64. > http://lkml.kernel.org/r/mvmmvfy37g1.fsf@hawking.suse.de > > The problem is page fault handler supports only accessed flag emulation > for THP page of SW-dirty/accessed architecture. > > This patch enables dirty-bit emulation for those architectures. > Without it, MADV_FREE makes application hang by repeated fault forever. > > [1] b8d3c4c3009d, mm/huge_memory.c: don't split THP page when MADV_FREE syscall is called Successfully tested a backport to 4.9. Andreas. -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different." -- 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