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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 23FE3C433E0 for ; Wed, 24 Jun 2020 00:21:22 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D593820B80 for ; Wed, 24 Jun 2020 00:21:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=intel-com.20150623.gappssmtp.com header.i=@intel-com.20150623.gappssmtp.com header.b="ssqhSLNF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D593820B80 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5C1946B0002; Tue, 23 Jun 2020 20:21:21 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 54A086B0003; Tue, 23 Jun 2020 20:21:21 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4128D6B0005; Tue, 23 Jun 2020 20:21:21 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0185.hostedemail.com [216.40.44.185]) by kanga.kvack.org (Postfix) with ESMTP id 26E416B0002 for ; Tue, 23 Jun 2020 20:21:21 -0400 (EDT) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 922582DFA for ; Wed, 24 Jun 2020 00:21:20 +0000 (UTC) X-FDA: 76962201120.16.vein96_480367626e3f Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin16.hostedemail.com (Postfix) with ESMTP id 69319100E6903 for ; Wed, 24 Jun 2020 00:21:20 +0000 (UTC) X-HE-Tag: vein96_480367626e3f X-Filterd-Recvd-Size: 3290 Received: from mail-ed1-f68.google.com (mail-ed1-f68.google.com [209.85.208.68]) by imf28.hostedemail.com (Postfix) with ESMTP for ; Wed, 24 Jun 2020 00:21:19 +0000 (UTC) Received: by mail-ed1-f68.google.com with SMTP id s28so135903edw.11 for ; Tue, 23 Jun 2020 17:21:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=intel-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YjofI1mwRo44tuHI1N5pBCiCgd6VCF1mc9VUJRDcqIs=; b=ssqhSLNFQwECvtfaqEByEmRnEvWZatoj9uZz/B5DwW54j2FQkD+Mz8lf986nWsFj/O 1VC/kYFfNJO2rSdKjYE0GZCOUe5M5hJ5dg2KoN+JnjPhFOOrYlBmMlFRDatO0eEcxkR0 ksGOcOp+yRJistWUEvSGzHGi0hWfgHApW536ZGxkx/ImlMQKKXTcRuHSTIeBt7JQ81Yh HPEW+6hx5rs1StxvLyah0FQP6QKXp7MUU5rjy9rgkp9osi1jCGckkybB+xUVoa19Tskt VcALBCPvxE2v4E3Do0asAE3bqTsJ2fs0G4MkURwA7zCpig8K7hrKmGW86vThgpxSuA/t QChg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YjofI1mwRo44tuHI1N5pBCiCgd6VCF1mc9VUJRDcqIs=; b=YPSdQmJdAE06b0jgFEq29EUYXcZjs+c/Z0Le0gqebPC0NPY+nSOAuMGCVWuVlfaxWT XajQ+18E7a5lqJ407RRjoIs8RL3+dqv+lCzlf3aSIXfVxYSWf8lTNEh4iHz5wHB6qQMz l57e4mzmuIEBlJVW5LdSHAHe/LzzvRgyU3gogsi8vhiu+mui8yUcOfcCW8CuEvQksgsr 68eaJ8qkEtzVWEHnUluR84WmQywvij50emlBcKqM8F+YPFQD2e0dMmuyH9tCfJ3U9F6c Q5dLY+Z12m7g2EBRg9u4FbR4q8joFaWP/MbNg2DfzqYmHDjRwOBm7eBCPJcgx4Dvm3ZF ySAw== X-Gm-Message-State: AOAM530rRG+hGJntBoYQbqzdDb7reJL/QtWgL0fzeOAD8Ub4f0DdqYV9 mGk28x4RnPjh0guS62EUFztTCODVttJfoPeBz8DN/A== X-Google-Smtp-Source: ABdhPJw83ckqM7XvH578t3C1pW3kyuRas4cnGlU5TxmWEVYr+CfscQ2B8N8wRKhF8WgJl+y1psSndTTLHtMHgYWVAto= X-Received: by 2002:a05:6402:21c2:: with SMTP id bi2mr24132581edb.296.1592958078019; Tue, 23 Jun 2020 17:21:18 -0700 (PDT) MIME-Version: 1.0 References: <20200623094258.6705-1-richard.weiyang@linux.alibaba.com> In-Reply-To: <20200623094258.6705-1-richard.weiyang@linux.alibaba.com> From: Dan Williams Date: Tue, 23 Jun 2020 17:21:06 -0700 Message-ID: Subject: Re: [PATCH] mm/spase: never partially remove memmap for early section To: Wei Yang Cc: Andrew Morton , Oscar Salvador , Linux MM , Linux Kernel Mailing List , David Hildenbrand Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 69319100E6903 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 Tue, Jun 23, 2020 at 2:43 AM Wei Yang wrote: > > For early sections, we assumes its memmap will never be partially > removed. But current behavior breaks this. Where do we assume that? The primary use case for this was mapping pmem that collides with System-RAM in the same 128MB section. That collision will certainly be depopulated on-demand depending on the state of the pmem device. So, I'm not understanding the problem or the benefit of this change.