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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 C7BF9C433E6 for ; Wed, 22 Jul 2020 12:50:41 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 880A9205CB for ; Wed, 22 Jul 2020 12:50:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Zz0cLQ0+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 880A9205CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ICLXHCDkYdMlp2kaeU6z7iIO1ScvEDWLnxQ0iTfyZrw=; b=Zz0cLQ0+VCSbDbj+QWU+ucsLN CljhKtzLRnPRB8c8R+WdTa8iL0nmbHOcNtHZEKQc1i/AJH/OwZyhJvyIWmtQ8Y6Rx5GI56FlnnlLV 5lRsDMeA6kHZYBD/pYRr+VfGgFgXXtysanGmQjLQqE1Ew+YsQ85ugXkPARpx2Mt5hnV4CVsLDCEkW dyQwjRp7onmOaRJ3g7xOSMFBqvLv00dttSguejlHgyElRCVcs7fGq3S2tFHKBWr9k4neO4rLQD0OW 37Cnp98nJSb2VuW9ItfpUgky/day2UmDGPleCSHBstXXQtmt6tgilahiHENFDhLUh9clwqkEIIikB 2PfX99eUQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyEBS-00019h-Pb; Wed, 22 Jul 2020 12:49:18 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jyEBQ-00018r-8c for linux-arm-kernel@lists.infradead.org; Wed, 22 Jul 2020 12:49:17 +0000 Received: from gaia (unknown [95.146.230.158]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 471B520729; Wed, 22 Jul 2020 12:49:13 +0000 (UTC) Date: Wed, 22 Jul 2020 13:49:10 +0100 From: Catalin Marinas To: "liwei (CM)" Subject: Re: =?utf-8?B?562U5aSNOiBbUEFUQ0hdIGFybTY0?= =?utf-8?B?OiBtbTogZnJl?= =?utf-8?Q?e?= unused memmap for sparse memory model that define VMEMMAP Message-ID: <20200722124910.GE27540@gaia> References: <20200721073203.107862-1-liwei213@huawei.com> <20200722060705.GK802087@linux.ibm.com> <1699CE87DE933F49876AD744B5DC140F2312E948@dggemm526-mbx.china.huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1699CE87DE933F49876AD744B5DC140F2312E948@dggemm526-mbx.china.huawei.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200722_084916_431172_C7C1FFC9 X-CRM114-Status: GOOD ( 13.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "Song Bao Hua \(Barry Song\)" , "linux-arm-kernel@lists.infradead.org" , "steve.capper@arm.com" , "Chenfeng \(puck\)" , sujunfei , "linux-kernel@vger.kernel.org" , fengbaopeng , zhaojiapeng , "Xiaqing \(A\)" , Mike Rapoport , "will@kernel.org" , "nsaenzjulienne@suse.de" , butao Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Jul 22, 2020 at 08:41:17AM +0000, liwei (CM) wrote: > Mike Rapoport wrote: > > On Tue, Jul 21, 2020 at 03:32:03PM +0800, Wei Li wrote: > > > For the memory hole, sparse memory model that define SPARSEMEM_VMEMMAP > > > do not free the reserved memory for the page map, this patch do it. > > > > Are there numbers showing how much memory is actually freed? > > > > The freeing of empty memmap would become rather complex with these > > changes, do the memory savings justify it? > > In the sparse memory model, the size of a section is 1 GB > (SECTION_SIZE_BITS 30) by default. Can we reduce SECTION_SIZE_BITS instead? Say 26? -- Catalin _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel