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=-5.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 C4C92CA9EC3 for ; Thu, 31 Oct 2019 07:25:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 969B52083E for ; Thu, 31 Oct 2019 07:25:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572506758; bh=+EcIU3jhDkSxgTKIw2tuddqMGVSzQ3AmggDk+3PcM50=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=NzIWRSx4VZr6E5Vn3sRv44sP/3/G7j8G99qX4hvmrgg7PiqKEJGofCzrwGmdDbeEy YMa9QAUymva+rV/y37mbwNLQODvgWumuP3PExN2P86E5I/90Vh6vyq/BQH88N8w6aa z63hF9HDTS/OPo3RCMkJoYVhwyoJfIHaQUS5H9D8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726789AbfJaHZ5 (ORCPT ); Thu, 31 Oct 2019 03:25:57 -0400 Received: from mx2.suse.de ([195.135.220.15]:44144 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726490AbfJaHZ5 (ORCPT ); Thu, 31 Oct 2019 03:25:57 -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 DAE22AEAF; Thu, 31 Oct 2019 07:25:55 +0000 (UTC) Date: Thu, 31 Oct 2019 08:25:55 +0100 From: Michal Hocko To: Vincent Whitchurch Cc: Pavel Tatashin , "akpm@linux-foundation.org" , "osalvador@suse.de" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] mm/sparse: Consistently do not zero memmap Message-ID: <20191031072555.GA13102@dhcp22.suse.cz> References: <20191030131122.8256-1-vincent.whitchurch@axis.com> <20191030132958.GD31513@dhcp22.suse.cz> <20191030140216.i26n22asgafckfxy@axis.com> <20191030141259.GE31513@dhcp22.suse.cz> <20191030153150.GI31513@dhcp22.suse.cz> <20191030173123.GK31513@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191030173123.GK31513@dhcp22.suse.cz> 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 Vincent, could you give this a try please? It would be even better if you could add some debugging to measure the overhead. Let me know if you need any help with a debugging patch. Thanks! On Wed 30-10-19 18:31:23, Michal Hocko wrote: [...] > What about this? It still aligns to the size but that should be > correctly done to the section size level. > > diff --git a/mm/sparse.c b/mm/sparse.c > index 72f010d9bff5..ab1e6175ac9a 100644 > --- a/mm/sparse.c > +++ b/mm/sparse.c > @@ -456,8 +456,7 @@ struct page __init *__populate_section_memmap(unsigned long pfn, > if (map) > return map; > > - map = memblock_alloc_try_nid(size, > - PAGE_SIZE, addr, > + map = memblock_alloc_try_nid(size, size, addr, > MEMBLOCK_ALLOC_ACCESSIBLE, nid); > if (!map) > panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n", > @@ -474,8 +473,13 @@ static void __init sparse_buffer_init(unsigned long size, int nid) > { > phys_addr_t addr = __pa(MAX_DMA_ADDRESS); > WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */ > + /* > + * Pre-allocated buffer is mainly used by __populate_section_memmap > + * and we want it to be properly aligned to the section size - this is > + * especially the case for VMEMMAP which maps memmap to PMDs > + */ > sparsemap_buf = > - memblock_alloc_try_nid_raw(size, PAGE_SIZE, > + memblock_alloc_try_nid_raw(size, section_map_size(), > addr, > MEMBLOCK_ALLOC_ACCESSIBLE, nid); > sparsemap_buf_end = sparsemap_buf + size; > > -- > Michal Hocko > SUSE Labs -- Michal Hocko SUSE Labs