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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 CD48DC433DB for ; Thu, 18 Feb 2021 02:04:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C22E64E4B for ; Thu, 18 Feb 2021 02:04:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229806AbhBRCDp (ORCPT ); Wed, 17 Feb 2021 21:03:45 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:44895 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229708AbhBRCDo (ORCPT ); Wed, 17 Feb 2021 21:03:44 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1613613737; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=s59KdTmSQrBsPD+fUMSiJY2kWYO8ArD+gPj0+UsCDBk=; b=OLmfRZi/t6XRr3bwjRSYWvAhFLuXXFYukNOxA0mWstOGs2H43xfi+T7RRrmbO6n/oHl/nr am80nwz0Kv9w4bajyU5T1nRoYNcm9l5K+5a/bw6pZ1T/uMfO/us8hlGtibiMMKZU7gnxAp QRUCynbtSipmtycM59X8bz04pB9WGxs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-578-Rduto0FTMjKAg80OdDaLGA-1; Wed, 17 Feb 2021 21:02:13 -0500 X-MC-Unique: Rduto0FTMjKAg80OdDaLGA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 86C555154; Thu, 18 Feb 2021 02:02:10 +0000 (UTC) Received: from localhost (ovpn-12-112.pek2.redhat.com [10.72.12.112]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 51C0D6F13C; Thu, 18 Feb 2021 02:02:06 +0000 (UTC) Date: Thu, 18 Feb 2021 10:02:03 +0800 From: Baoquan He To: Saeed Mirzamohammadi Cc: john.p.donnelly@oracle.com, Dave Young , Vivek Goyal , Jonathan Corbet , "Paul E. McKenney" , Randy Dunlap , Andrew Morton , Thomas Gleixner , Mauro Carvalho Chehab , Mike Kravetz , "Guilherme G. Piccoli" , Kees Cook , "Peter Zijlstra (Intel)" , Ingo Molnar , "Steven Rostedt (VMware)" , Frederic Weisbecker , YiFei Zhu , Josh Poimboeuf , Mike Rapoport , Masahiro Yamada , Sami Tolvanen , Christian Brauner , Stephen Boyd , Andrey Konovalov , kexec@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 1/1] kernel/crash_core: Add crashkernel=auto for vmcore creation Message-ID: <20210218020203.GC2871@MiWiFi-R3L-srv> References: <20210211180814.69708-1-saeed.mirzamohammadi@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210211180814.69708-1-saeed.mirzamohammadi@oracle.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 02/11/21 at 10:08am, Saeed Mirzamohammadi wrote: > This adds crashkernel=auto feature to configure reserved memory for > vmcore creation. CONFIG_CRASH_AUTO_STR is defined to be set for > different kernel distributions and different archs based on their > needs. > > Signed-off-by: Saeed Mirzamohammadi > Signed-off-by: John Donnelly > Tested-by: John Donnelly > --- > Documentation/admin-guide/kdump/kdump.rst | 3 ++- > .../admin-guide/kernel-parameters.txt | 6 +++++ > arch/Kconfig | 24 +++++++++++++++++++ > kernel/crash_core.c | 7 ++++++ > 4 files changed, 39 insertions(+), 1 deletion(-) > > diff --git a/Documentation/admin-guide/kdump/kdump.rst b/Documentation/admin-guide/kdump/kdump.rst > index 2da65fef2a1c..e55cdc404c6b 100644 > --- a/Documentation/admin-guide/kdump/kdump.rst > +++ b/Documentation/admin-guide/kdump/kdump.rst > @@ -285,7 +285,8 @@ This would mean: > 2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M > 3) if the RAM size is larger than 2G, then reserve 128M > > - > +Or you can use crashkernel=auto to choose the crash kernel memory size > +based on the recommended configuration set for each arch. > > Boot into System Kernel > ======================= > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 7d4e523646c3..aa2099465458 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -736,6 +736,12 @@ > a memory unit (amount[KMG]). See also > Documentation/admin-guide/kdump/kdump.rst for an example. > > + crashkernel=auto > + [KNL] This parameter will set the reserved memory for > + the crash kernel based on the value of the CRASH_AUTO_STR > + that is the best effort estimation for each arch. See also > + arch/Kconfig for further details. > + > crashkernel=size[KMG],high > [KNL, X86-64] range could be above 4G. Allow kernel > to allocate physical memory region from top, so could > diff --git a/arch/Kconfig b/arch/Kconfig > index af14a567b493..f87c88ffa2f8 100644 > --- a/arch/Kconfig > +++ b/arch/Kconfig > @@ -14,6 +14,30 @@ menu "General architecture-dependent options" > config CRASH_CORE > bool > > +if CRASH_CORE > + > +config CRASH_AUTO_STR > + string "Memory reserved for crash kernel" > + depends on CRASH_CORE > + default "1G-64G:128M,64G-1T:256M,1T-:512M" > + help > + This configures the reserved memory dependent > + on the value of System RAM. The syntax is: > + crashkernel=:[,:,...][@offset] > + range=start-[end] > + > + For example: > + crashkernel=512M-2G:64M,2G-:128M > + > + This would mean: > + > + 1) if the RAM is smaller than 512M, then don't reserve anything > + (this is the "rescue" case) > + 2) if the RAM size is between 512M and 2G (exclusive), then reserve 64M > + 3) if the RAM size is larger than 2G, then reserve 128M > + > +endif # CRASH_CORE Wondering if this CRASH_CORE ifdeffery is a little redundent here since CRASH_CORE dependency has been added. Except of this, I like this patch. As we discussed in private threads, we can try to push it into mainline and continue improving later. > + > config KEXEC_CORE > select CRASH_CORE > bool > diff --git a/kernel/crash_core.c b/kernel/crash_core.c > index 106e4500fd53..ab0a2b4b1ffa 100644 > --- a/kernel/crash_core.c > +++ b/kernel/crash_core.c > @@ -7,6 +7,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -250,6 +251,12 @@ static int __init __parse_crashkernel(char *cmdline, > if (suffix) > return parse_crashkernel_suffix(ck_cmdline, crash_size, > suffix); > +#ifdef CONFIG_CRASH_AUTO_STR > + if (strncmp(ck_cmdline, "auto", 4) == 0) { > + ck_cmdline = CONFIG_CRASH_AUTO_STR; > + pr_info("Using crashkernel=auto, the size chosen is a best effort estimation.\n"); > + } > +#endif > /* > * if the commandline contains a ':', then that's the extended > * syntax -- if not, it must be the classic syntax > -- > 2.27.0 >