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=-3.8 required=3.0 tests=BAYES_00,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 F2F24C433E0 for ; Sat, 30 Jan 2021 18:48:28 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4F89264DD9 for ; Sat, 30 Jan 2021 18:48:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4F89264DD9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=colorremedies.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4EFD36B0005; Sat, 30 Jan 2021 13:48:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 49F326B0006; Sat, 30 Jan 2021 13:48:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3B4E26B006C; Sat, 30 Jan 2021 13:48:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0232.hostedemail.com [216.40.44.232]) by kanga.kvack.org (Postfix) with ESMTP id 26CF06B0005 for ; Sat, 30 Jan 2021 13:48:27 -0500 (EST) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D9DF38249980 for ; Sat, 30 Jan 2021 18:48:26 +0000 (UTC) X-FDA: 77763327012.02.tin57_1012ded275b3 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin02.hostedemail.com (Postfix) with ESMTP id C137110097AA1 for ; Sat, 30 Jan 2021 18:48:26 +0000 (UTC) X-HE-Tag: tin57_1012ded275b3 X-Filterd-Recvd-Size: 3601 Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) by imf19.hostedemail.com (Postfix) with ESMTP for ; Sat, 30 Jan 2021 18:48:26 +0000 (UTC) Received: by mail-wr1-f51.google.com with SMTP id m13so12224959wro.12 for ; Sat, 30 Jan 2021 10:48:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=colorremedies-com.20150623.gappssmtp.com; s=20150623; h=mime-version:from:date:message-id:subject:to; bh=5KRZkzdxXQmpkKFn5dp1ap8aEkvaUeyvXtwHQ1TX7Xo=; b=vL990OCuEjWLma6OQ6sfmIQC31dfi2i/zH4/oRgWE12PfUSyWF86JRzPElMewq5uUq heYuzedE1pJzfIRc06Ne7oFFZEE5+zvvYhP/NmL0tmrXSrJbgyCs0FDaIL2MxCbYWSjE kipPLaqSHOIVVG4FBb4E+Ej2KklcC/fofSOt1Kp49LUnzB+RrjNFCo0qXqB2+56bh554 jMDxHZoA5DMO3XSYVgwErQJ9TKPGPV5l9Affxhh8pzRG5JG1B9wWb9VhMEbUh8hmILjr TEFvI3apq1MUQOxhkZTner+lOCFIpcTjwTV8XVUaYuUg0AgXGCLkG7MM5Om7HkI2JnEe GFNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=5KRZkzdxXQmpkKFn5dp1ap8aEkvaUeyvXtwHQ1TX7Xo=; b=MZYLGbFmPco3xKUUkR4IQ9Ff+8wvD6cQdBRo6M+SazRwN4jmS/adimEJDoeKmXk0u+ I/4b7UryGNP/2RUDg1XKu5X+JkGS37ZfSlfMzNqvTOJ+YYjrP8IJf0r3s3biv+WufuSk SK9E2AASps+26yAT04inmslve9pQCuCbeK4rXLqwXQtANbj6sR28+WAH2XpGy9CDg8ds Nr5oIVvxqrJOobW577pSHfYL2/JKtgn5fgDDYwxRs3U9PFwMidbLtGwDu5aYnVShzTiq /f8wiaiL7xjTZk/nR2NTJX30hdmsXxJ0HTci+x7Bv9EwwvKz+8i8YpX0+e+GfoBSPtm3 zP0A== X-Gm-Message-State: AOAM5310x7KpRmKnyY1cGjjSaLiP7uiq9KvecFs5N0+zKpdn0XW5DPoc XLUnWwlVmDLkywdAInmaoCnx/Q+Aj5HNN6mi0hGfSFU0cRw3DUfY X-Google-Smtp-Source: ABdhPJw6HKLXKCMAvUwTYCSrBbq1G7WhwWvSl+lgj/pa9lpG+8ONBEe6GvVK3nnYSbnlYfgO6WJGx3xb3HoTwFxgcB0= X-Received: by 2002:a5d:6686:: with SMTP id l6mr10512752wru.236.1612032504697; Sat, 30 Jan 2021 10:48:24 -0800 (PST) MIME-Version: 1.0 From: Chris Murphy Date: Sat, 30 Jan 2021 11:48:08 -0700 Message-ID: Subject: 5.11 "debug" missing 20-30% memory, and exceptionally high reserved To: Linux Memory Management List Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000489, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Fedora is seeing a significantly reduced /proc/meminfo MemTotal with "debug" 5.11 series kernels. The problem isn't happening with "nodebug" kernels. The other possible instigator is GCC 11.0.0 is being used (all 5.10 series, nodebug and debug, are built with GCC 10.2.1). We're still doing some tests to narrow it down. The problem reproduces on x86_64 (no info on other archs yet) both baremetal and qemu-kvm. And first manifests with this line: 5.11.0-0.rc5.134.fc34.x86_64+debug Jan 28 13:56:08 flap.local kernel: Memory: 6547356K/8276392K available (43019K kernel code, 11036K rwdata, 27184K rodata, 5036K init, 31780K bss, 1728780K reserved, 0K cma-reserved) 5.11.0-0.rc5.134.fc34.x86_64 Jan 28 13:54:19 flap.local kernel: Memory: 7915056K/8276392K available (16393K kernel code, 3469K rwdata, 26796K rodata, 2544K init, 5484K bss, 361076K reserved, 0K cma-reserved) Reserved memory seems quite high in the debug case. Downstream bug report has dmesg for 5.11.0-0.rc5.134.fc34.x86_64+debug, and kernel config attachments. Bug 1921923 - Kernel under-reporting or hiding about a third of available memory in "debug" 5.11 series https://bugzilla.redhat.com/show_bug.cgi?id=1921923 -- Chris Murphy