From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from userp1040.oracle.com (userp1040.oracle.com [156.151.31.81]) (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 3y69Zw6Hf2zDqlP for ; Wed, 4 Oct 2017 07:28:08 +1100 (AEDT) Subject: Re: [PATCH v9 12/12] mm: stop zeroing memory during allocation in vmemmap From: Pasha Tatashin To: Michal Hocko Cc: linux-kernel@vger.kernel.org, sparclinux@vger.kernel.org, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, kasan-dev@googlegroups.com, borntraeger@de.ibm.com, heiko.carstens@de.ibm.com, davem@davemloft.net, willy@infradead.org, ard.biesheuvel@linaro.org, mark.rutland@arm.com, will.deacon@arm.com, catalin.marinas@arm.com, sam@ravnborg.org, mgorman@techsingularity.net, steven.sistare@oracle.com, daniel.m.jordan@oracle.com, bob.picco@oracle.com References: <20170920201714.19817-1-pasha.tatashin@oracle.com> <20170920201714.19817-13-pasha.tatashin@oracle.com> <20171003131952.aqq377pjug5me6go@dhcp22.suse.cz> Message-ID: Date: Tue, 3 Oct 2017 16:26:51 -0400 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Michal, I decided not to merge these two patches, because in addition to sparc optimization move, we have this dependancies: mm: zero reserved and unavailable struct pages must be before mm: stop zeroing memory during allocation in vmemmap. Otherwise, we can end-up with struct pages that are not zeroed properly. However, the first patch depends on mm: zero struct pages during initialization As it uses mm_zero_struct_page(). Pasha On 10/03/2017 11:34 AM, Pasha Tatashin wrote: > On 10/03/2017 09:19 AM, Michal Hocko wrote: >> On Wed 20-09-17 16:17:14, Pavel Tatashin wrote: >>> vmemmap_alloc_block() will no longer zero the block, so zero memory >>> at its call sites for everything except struct pages.  Struct page >>> memory >>> is zero'd by struct page initialization. >>> >>> Replace allocators in sprase-vmemmap to use the non-zeroing version. So, >>> we will get the performance improvement by zeroing the memory in >>> parallel >>> when struct pages are zeroed. >> >> Is it possible to merge this patch with >> http://lkml.kernel.org/r/20170920201714.19817-7-pasha.tatashin@oracle.com > > Yes, I will do that. It would also require re-arranging > [PATCH v9 07/12] sparc64: optimized struct page zeroing > optimization to come after this patch. > > Pasha