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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 C1FBBC433E0 for ; Fri, 3 Jul 2020 06:32:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8AF0920772 for ; Fri, 3 Jul 2020 06:32:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8AF0920772 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 06B3C8D001A; Fri, 3 Jul 2020 02:32:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 01B3B8D0010; Fri, 3 Jul 2020 02:32:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E72FA8D001A; Fri, 3 Jul 2020 02:32:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id D1DFD8D0010 for ; Fri, 3 Jul 2020 02:32:34 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4CF5152BA for ; Fri, 3 Jul 2020 06:32:34 +0000 (UTC) X-FDA: 76995795828.17.sound04_221804c26e8f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 13122180D0181 for ; Fri, 3 Jul 2020 06:32:34 +0000 (UTC) X-HE-Tag: sound04_221804c26e8f X-Filterd-Recvd-Size: 4414 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf21.hostedemail.com (Postfix) with ESMTP for ; Fri, 3 Jul 2020 06:32:33 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id ADD9431B; Thu, 2 Jul 2020 23:32:32 -0700 (PDT) Received: from [10.163.85.168] (unknown [10.163.85.168]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B20083F73C; Thu, 2 Jul 2020 23:32:27 -0700 (PDT) Subject: Re: [PATCH V3 (RESEND) 2/3] mm/sparsemem: Enable vmem_altmap support in vmemmap_alloc_block_buf() To: Catalin Marinas Cc: linux-mm@kvack.org, Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Andrew Morton , x86@kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <1592442930-9380-1-git-send-email-anshuman.khandual@arm.com> <1592442930-9380-3-git-send-email-anshuman.khandual@arm.com> <20200702140752.GF22241@gaia> From: Anshuman Khandual Message-ID: Date: Fri, 3 Jul 2020 12:02:11 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200702140752.GF22241@gaia> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 13122180D0181 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 07/02/2020 07:37 PM, Catalin Marinas wrote: > On Thu, Jun 18, 2020 at 06:45:29AM +0530, Anshuman Khandual wrote: >> There are many instances where vmemap allocation is often switched between >> regular memory and device memory just based on whether altmap is available >> or not. vmemmap_alloc_block_buf() is used in various platforms to allocate >> vmemmap mappings. Lets also enable it to handle altmap based device memory >> allocation along with existing regular memory allocations. This will help >> in avoiding the altmap based allocation switch in many places. >> >> While here also implement a regular memory allocation fallback mechanism >> when the first preferred device memory allocation fails. This will ensure >> preserving the existing semantics on powerpc platform. To summarize there >> are three different methods to call vmemmap_alloc_block_buf(). >> >> (., NULL, false) /* Allocate from system RAM */ >> (., altmap, false) /* Allocate from altmap without any fallback */ >> (., altmap, true) /* Allocate from altmap with fallback (system RAM) */ > [...] >> diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c >> index bc73abf0bc25..01e25b56eccb 100644 >> --- a/arch/powerpc/mm/init_64.c >> +++ b/arch/powerpc/mm/init_64.c >> @@ -225,12 +225,12 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, >> * fall back to system memory if the altmap allocation fail. >> */ >> if (altmap && !altmap_cross_boundary(altmap, start, page_size)) { >> - p = altmap_alloc_block_buf(page_size, altmap); >> - if (!p) >> - pr_debug("altmap block allocation failed, falling back to system memory"); >> + p = vmemmap_alloc_block_buf(page_size, node, >> + altmap, true); >> + } else { >> + p = vmemmap_alloc_block_buf(page_size, node, >> + NULL, false); >> } >> - if (!p) >> - p = vmemmap_alloc_block_buf(page_size, node); >> if (!p) >> return -ENOMEM; > > Is the fallback argument actually necessary. It may be cleaner to just > leave the code as is with the choice between altmap and NULL. If an arch > needs a fallback (only powerpc), they have the fallback in place > already. I don't see the powerpc code any better after this change. > > I'm fine with the altmap argument though. Okay. Will drop 'fallback' from vmemmap_alloc_block_buf() and update the callers. There will also be a single change in the subsequent patch i.e vmemmap_alloc_block_buf(PMD_SIZE, node, altmap).