From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB6DEC43334 for ; Wed, 5 Sep 2018 06:24:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 68E9120659 for ; Wed, 5 Sep 2018 06:24:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68E9120659 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727636AbeIEKxI (ORCPT ); Wed, 5 Sep 2018 06:53:08 -0400 Received: from mx2.suse.de ([195.135.220.15]:33454 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726272AbeIEKxI (ORCPT ); Wed, 5 Sep 2018 06:53:08 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id D93E5ABBE; Wed, 5 Sep 2018 06:24:29 +0000 (UTC) Date: Wed, 5 Sep 2018 08:24:28 +0200 From: Michal Hocko To: Alexander Duyck Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, alexander.h.duyck@intel.com, pavel.tatashin@microsoft.com, akpm@linux-foundation.org, mingo@kernel.org, kirill.shutemov@linux.intel.com Subject: Re: [PATCH 2/2] mm: Create non-atomic version of SetPageReserved for init use Message-ID: <20180905062428.GV14951@dhcp22.suse.cz> References: <20180904181550.4416.50701.stgit@localhost.localdomain> <20180904183345.4416.76515.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180904183345.4416.76515.stgit@localhost.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 04-09-18 11:33:45, Alexander Duyck wrote: > From: Alexander Duyck > > It doesn't make much sense to use the atomic SetPageReserved at init time > when we are using memset to clear the memory and manipulating the page > flags via simple "&=" and "|=" operations in __init_single_page. > > This patch adds a non-atomic version __SetPageReserved that can be used > during page init and shows about a 10% improvement in initialization times > on the systems I have available for testing. I agree with Dave about a comment is due. I am also quite surprised that this leads to such a large improvement. Could you be more specific about your test and machines you were testing on? Other than that the patch makes sense to me. > Signed-off-by: Alexander Duyck With the above addressed, feel free to add Acked-by: Michal Hocko Thanks! > --- > include/linux/page-flags.h | 1 + > mm/page_alloc.c | 4 ++-- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h > index 74bee8cecf4c..57ec3fef7e9f 100644 > --- a/include/linux/page-flags.h > +++ b/include/linux/page-flags.h > @@ -292,6 +292,7 @@ static inline int PagePoisoned(const struct page *page) > > PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) > __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) > + __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) > PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) > __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) > __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 05e983f42316..9c7d6e971630 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -1231,7 +1231,7 @@ void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end) > /* Avoid false-positive PageTail() */ > INIT_LIST_HEAD(&page->lru); > > - SetPageReserved(page); > + __SetPageReserved(page); > } > } > } > @@ -5518,7 +5518,7 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone, > page = pfn_to_page(pfn); > __init_single_page(page, pfn, zone, nid); > if (context == MEMMAP_HOTPLUG) > - SetPageReserved(page); > + __SetPageReserved(page); > > /* > * Mark the block movable so that blocks are reserved for > -- Michal Hocko SUSE Labs