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[195.135.220.15]) by mx.google.com with ESMTPS id i57si2412242ede.57.2019.03.01.06.43.20 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 01 Mar 2019 06:43:20 -0800 (PST) Received-SPF: pass (google.com: domain of vbabka@suse.cz designates 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=pass (google.com: domain of vbabka@suse.cz designates 195.135.220.15 as permitted sender) smtp.mailfrom=vbabka@suse.cz 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 426D0ADE1; Fri, 1 Mar 2019 14:43:20 +0000 (UTC) Subject: Re: [PATCH 2/3] mm: separate memory allocation and actual work in alloc_vmap_area() To: Roman Gushchin , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Matthew Wilcox , Johannes Weiner , kernel-team@fb.com, Roman Gushchin References: <20190225203037.1317-1-guro@fb.com> <20190225203037.1317-3-guro@fb.com> From: Vlastimil Babka Openpgp: preference=signencrypt Autocrypt: addr=vbabka@suse.cz; 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Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.5.1 MIME-Version: 1.0 In-Reply-To: <20190225203037.1317-3-guro@fb.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit 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 2/25/19 9:30 PM, Roman Gushchin wrote: > alloc_vmap_area() is allocating memory for the vmap_area, and > performing the actual lookup of the vm area and vmap_area > initialization. > > This prevents us from using a pre-allocated memory for the map_area > structure, which can be used in some cases to minimize the number > of required memory allocations. Hmm, but that doesn't happen here or in the later patch, right? The only caller of init_vmap_area() is alloc_vmap_area(). What am I missing? > Let's keep the memory allocation part in alloc_vmap_area() and > separate everything else into init_vmap_area(). > > Signed-off-by: Roman Gushchin > Acked-by: Johannes Weiner > Reviewed-by: Matthew Wilcox