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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, T_DKIMWL_WL_MED,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 18E49C6778C for ; Tue, 3 Jul 2018 18:35:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D43B22454 for ; Tue, 3 Jul 2018 18:35:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cisco.com header.i=@cisco.com header.b="k0NI31+W" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D43B22454 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=cisco.com 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 S934509AbeGCSff (ORCPT ); Tue, 3 Jul 2018 14:35:35 -0400 Received: from rcdn-iport-2.cisco.com ([173.37.86.73]:14860 "EHLO rcdn-iport-2.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934381AbeGCSfe (ORCPT ); Tue, 3 Jul 2018 14:35:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=1581; q=dns/txt; s=iport; t=1530642934; x=1531852534; h=from:to:cc:subject:date:message-id:references: in-reply-to:content-transfer-encoding:mime-version; bh=3NhigFavGuypKnyqj5PVuKWWzcUcqN5DuFXDX9u2gOo=; b=k0NI31+W8j777uwnWRBa9gmWzPSTAWdl9+FFgx2hzXE7w6pcLuZnMNWC lk3BZmC5JLUoReMS+jmTdusjOitbrSrkrZmAhSEDNBm836k7xn2UjuNtn o2p/FI+3uRqgnNbAA29vqa2glqytvcNgoWcb96n1b+AqMhbqJEBGsG8R5 Y=; X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: =?us-ascii?q?A0DJAAABwTtb/5NdJa1cGQEBAQEBAQE?= =?us-ascii?q?BAQEBAQcBAQEBAYNJgWEoCotzjD6CB4Q6kG6BegsYhFQCghkhNBgBAgEBAgE?= =?us-ascii?q?BAm0ohTYBAQEBAwF4EAIBCBEEAQEBCSUPGQodCAIEDgWFIKsQiEuBOohtgVY?= =?us-ascii?q?/hB6EeoVWAodhhSuEWodlCQKLMINtgUCEDIgLkWICERMBgSQdOIFScBWDJJB?= =?us-ascii?q?Sb49fgRoBAQ?= X-IronPort-AV: E=Sophos;i="5.51,304,1526342400"; d="scan'208";a="422032920" Received: from rcdn-core-11.cisco.com ([173.37.93.147]) by rcdn-iport-2.cisco.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 03 Jul 2018 18:35:33 +0000 Received: from XCH-RTP-003.cisco.com (xch-rtp-003.cisco.com [64.101.220.143]) by rcdn-core-11.cisco.com (8.14.5/8.14.5) with ESMTP id w63IZWWK013924 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=FAIL); Tue, 3 Jul 2018 18:35:33 GMT Received: from xch-rtp-001.cisco.com (64.101.220.141) by XCH-RTP-003.cisco.com (64.101.220.143) with Microsoft SMTP Server (TLS) id 15.0.1320.4; Tue, 3 Jul 2018 14:35:32 -0400 Received: from xch-rtp-001.cisco.com ([64.101.220.141]) by XCH-RTP-001.cisco.com ([64.101.220.141]) with mapi id 15.00.1320.000; Tue, 3 Jul 2018 14:35:32 -0400 From: "Nikunj Kela (nkela)" To: Catalin Marinas CC: Will Deacon , "xe-kernel@external.cisco.com" , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH 2/2] arm64: add support for 43bit physical address Thread-Topic: [PATCH 2/2] arm64: add support for 43bit physical address Thread-Index: AQHUEkhUYrA/ILOIpk+9pyia5fOeYaR92oaA///4KMY= Date: Tue, 3 Jul 2018 18:35:32 +0000 Message-ID: <1530642932209.57184@cisco.com> References: <20180702210451.16057-2-nkela@cisco.com>,<20180703145626.g6pb4bgnrle2p2qf@armageddon.cambridge.arm.com> In-Reply-To: <20180703145626.g6pb4bgnrle2p2qf@armageddon.cambridge.arm.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.41.48.45] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We are trying to reduce the memory allocation needed for kdump kernel. We w= ant to reserve less than 32M for kdump kernel if possible. We are able to g= et ~14M saving by the proposed change. Below are the numbers before and aft= er the proposed change:=0A= =0A= With 48 bit physical address and 30 bit section size:=0A= --------------------------------------------------------------------=0A= =0A= Memory: 23052K/49152K available (3460K kernel code, 296K rwdata, 2436K roda= ta, 204K init, 179K bss, 26100K reserved, 0K cma-reserved)=0A= =0A= With 43 bit physical address and 27bit section size:=0A= --------------------------------------------------------------------=0A= =0A= Memory: 37284K/49152K available (3596K kernel code, 296K rwdata, 2408K roda= ta, 208K init, 173K bss, 11868K reserved, 0K cma-reserved)=0A= =0A= Thanks,=0A= -Nikunj=0A= ________________________________________=0A= From: Catalin Marinas =0A= Sent: Tuesday, July 3, 2018 7:56 AM=0A= To: Nikunj Kela (nkela)=0A= Cc: Will Deacon; xe-kernel@external.cisco.com; linux-kernel@vger.kernel.org= ; linux-arm-kernel@lists.infradead.org=0A= Subject: Re: [PATCH 2/2] arm64: add support for 43bit physical address=0A= =0A= On Mon, Jul 02, 2018 at 02:04:51PM -0700, Nikunj Kela wrote:=0A= > This patch adds support for 43bit physical address. Additionally,=0A= > this patch adds support for 27bit section size. This is useful in=0A= > reducing kernel memory usage. One usecase is in kdump kernel.=0A= =0A= Some numbers please.=0A= =0A= --=0A= Catalin=0A=