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Tue, 27 Aug 2024 02:22:39 -0400 X-MC-Unique: t7YesfeCNKOOuuMJdnOrxQ-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 6C07E19560B1; Tue, 27 Aug 2024 06:22:36 +0000 (UTC) Received: from localhost (unknown [10.72.112.42]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id C25D219560A3; Tue, 27 Aug 2024 06:22:33 +0000 (UTC) Date: Tue, 27 Aug 2024 14:22:28 +0800 From: Baoquan He To: John Paul Adrian Glaubitz Cc: Geert Uytterhoeven , Dave Vasilevsky , linuxppc-dev@lists.ozlabs.org, linux-sh@vger.kernel.org, mpe@ellerman.id.au, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, Reimar =?iso-8859-1?Q?D=F6ffinger?= Subject: Re: [PATCH] crash: Default to CRASH_DUMP=n when support for it is unlikely Message-ID: References: <20240823125156.104775-1-dave@vasilevsky.ca> <09c29a3c4879d4ce5d8b97fd60d8ba5e38bed979.camel@physik.fu-berlin.de> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Post: List-Subscribe: , , List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <09c29a3c4879d4ce5d8b97fd60d8ba5e38bed979.camel@physik.fu-berlin.de> X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 On 08/23/24 at 08:16pm, John Paul Adrian Glaubitz wrote: > Hi Geert, > > On Fri, 2024-08-23 at 15:13 +0200, Geert Uytterhoeven wrote: > > IMHO CRASH_DUMP should just default to n, like most kernel options, as > > it enables non-trivial extra functionality: the kernel source tree has > > more than 100 locations that check if CONFIG_CRASH_DUMP is enabled. > > I guess we should then revert that part of Baoquan's original patch. > > > What is so special about CRASH_DUMP, that it should be enabled by > > default? > > Let's ask Baoquan who made the original change to enable CRASH_DUMP by default. Sorry for late reply. It's me who enabled it by default when I clean up the messy Kconfig items related to kexec/kdump. Before the clean up, CONFIG_CRASH_DUMP only controlled a very small file including sevearl functions and macro definitions. But kernel codes took CRASH_DUMP as switch of kdump. About why it's enabled by default, as Michael has explained in another thread, distros usualy needs to enable it by default because vmcore dumping is a very important feature on servers, even guest instances. Even though kdump codes are enabled to built in, not providing crashkernel= value won't make vmcore dumping take effect, it won't cost system resources in that case. Thanks Baoquan