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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id D500EC433EF for ; Sun, 6 Mar 2022 01:23:03 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 265806B0071; Sat, 5 Mar 2022 20:23:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1EE5F6B0072; Sat, 5 Mar 2022 20:23:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0B72F6B0073; Sat, 5 Mar 2022 20:23:03 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id ED5136B0071 for ; Sat, 5 Mar 2022 20:23:02 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 87D2160AE4 for ; Sun, 6 Mar 2022 01:23:02 +0000 (UTC) X-FDA: 79212212604.15.2F4EE34 Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by imf28.hostedemail.com (Postfix) with ESMTP id B5CF8C0003 for ; Sun, 6 Mar 2022 01:23:01 +0000 (UTC) Received: by angie.orcam.me.uk (Postfix, from userid 500) id E6A1792009C; Sun, 6 Mar 2022 02:22:58 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id D7D5992009B; Sun, 6 Mar 2022 01:22:58 +0000 (GMT) Date: Sun, 6 Mar 2022 01:22:58 +0000 (GMT) From: "Maciej W. Rozycki" To: Mike Rapoport cc: Tiezhu Yang , Thomas Bogendoerfer , Andrew Morton , Xuefeng Li , linux-mips@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/4] MIPS: Modify mem= and memmap= parameter In-Reply-To: Message-ID: References: <1646108941-27919-1-git-send-email-yangtiezhu@loongson.cn> <8956c625-c18d-846e-3e65-7920776b27f3@loongson.cn> <4e10d7a4-3b3e-a220-8cd2-565614288950@loongson.cn> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: B5CF8C0003 X-Rspam-User: Authentication-Results: imf28.hostedemail.com; dkim=none; dmarc=none; spf=none (imf28.hostedemail.com: domain of macro@orcam.me.uk has no SPF policy when checking 78.133.224.34) smtp.mailfrom=macro@orcam.me.uk X-Stat-Signature: fx8kd8jdjcc5qyoo6g54zxxtt9jfw9nb X-HE-Tag: 1646529781-87948 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 Sat, 5 Mar 2022, Mike Rapoport wrote: > > There's nothing to implement as the MIPS port has supported arbitrary > > memory maps since Dec 11th, 2000; that's almost 22 years now. C.f.: > > , > > . > > You are right, and providing mem=X@Y for each contiguous memory range > should work even after 22 years. > I missed the fact that mem= can be repeated several times. Yep, I have now finally tracked down the original bootstrap log for the first try of that change: This DECstation is a DS5000/2x0 Loading R[23]00 MMU routines. CPU revision is: 00000230 Primary instruction cache 64kb, linesize 4 bytes Primary data cache 64kb, linesize 4 bytes Linux version 2.4.0-test5 (macro@macro.ds2.pg.gda.pl) (gcc version 2.95.3 19991030 (prerelease)) #16 Sun Aug 13 16:43:22 CEST 2000 PROM-provided physical RAM map: memory: 06800000 @ 00000000 memory: 00800000 @ 08000000 memory: 00800000 @ 0a000000 User-defined physical RAM map: memory: 06800000 @ 00000000 memory: 00800000 @ 08000000 memory: 00800000 @ 0a000000 memory: 00800000 @ 0c000000 On node 0 totalpages: 51200 zone(0): 51200 pages. zone(1): 0 pages. zone(2): 0 pages. Kernel command line: rw console=ttyS2 mem=104M@0M mem=8M@128M mem=8M@160M mem=8M@192M Calibrating delay loop... 39.85 BogoMIPS Memory: 127852k/204800k available (2403k kernel code, 76948k reserved, 610k data, 72k init) [...] NB that system is still in service, with more RAM since added. > > Sadly commit a09fc446fb6d ("[MIPS] setup.c: use early_param() for early > > command line parsing") removed last pieces of inline documentation; I > > don't know why things like that get approved, but neither I can take > > responsibility. > > This is sad indeed, but we still can update the kernel-parameters.txt with > a MIPS paragraph. Sure, patches are welcome. Maciej