From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from shards.monkeyblade.net (shards.monkeyblade.net [184.105.139.130]) (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 3xhnXr1qmjzDqLv for ; Wed, 30 Aug 2017 11:12:11 +1000 (AEST) Date: Tue, 29 Aug 2017 18:12:08 -0700 (PDT) Message-Id: <20170829.181208.171985548699678313.davem@davemloft.net> To: pasha.tatashin@oracle.com 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, willy@infradead.org, mhocko@kernel.org, ard.biesheuvel@linaro.org, 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 Subject: Re: [PATCH v7 07/11] sparc64: optimized struct page zeroing From: David Miller In-Reply-To: <1503972142-289376-8-git-send-email-pasha.tatashin@oracle.com> References: <1503972142-289376-1-git-send-email-pasha.tatashin@oracle.com> <1503972142-289376-8-git-send-email-pasha.tatashin@oracle.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Pavel Tatashin Date: Mon, 28 Aug 2017 22:02:18 -0400 > Add an optimized mm_zero_struct_page(), so struct page's are zeroed without > calling memset(). We do eight to ten regular stores based on the size of > struct page. Compiler optimizes out the conditions of switch() statement. > > SPARC-M6 with 15T of memory, single thread performance: > > BASE FIX OPTIMIZED_FIX > bootmem_init 28.440467985s 2.305674818s 2.305161615s > free_area_init_nodes 202.845901673s 225.343084508s 172.556506560s > -------------------------------------------- > Total 231.286369658s 227.648759326s 174.861668175s > > BASE: current linux > FIX: This patch series without "optimized struct page zeroing" > OPTIMIZED_FIX: This patch series including the current patch. > > bootmem_init() is where memory for struct pages is zeroed during > allocation. Note, about two seconds in this function is a fixed time: it > does not increase as memory is increased. > > Signed-off-by: Pavel Tatashin > Reviewed-by: Steven Sistare > Reviewed-by: Daniel Jordan > Reviewed-by: Bob Picco You should probably use initializing stores when you are doing 8 stores and we thus know the page struct is cache line aligned. But other than that: Acked-by: David S. Miller