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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 72660C982D0 for ; Sun, 20 Sep 2026 03:34:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=A7ZVtpRa4xG9tmEOcZ/WJOmfdObDCumvMarROr2J/Xo=; b=dFrpc003YfUg+fheEaa3kzljWB 7ufpZOx6zaE1kqbrmPsgM0Rm6kQBneD4Pkpal1ifJt6F+NUZi+Rlq/Y8NGTQ3QBQdLt5Wg2z2q/Mt d0N5KCjNyqQ/z5SSl4jHH0KqtnS9frP/hC5WTUOi/5XmChfANXgDcXJ9LgkpvNmNTNq0mRFHrqZ6c 1p0hFdyHv3vcMrRMgXT8X4OHfq6zpJznsQfe7yi6kSnnwiwIScHc5ACitchB0DvOFqGO8gY3CS5YT M4sX4czVVX4HOs1c6HD7kTnccUcM5pxIzbDGGKuVotMmu+w29CMPC4M3wySj3HM8fnJSOaWQnUwCS Ds2ZDFDw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x88JS-0000000GoCN-0Zdr; Sun, 20 Sep 2026 03:33:58 +0000 Received: from out-74.mta1.migadu.com ([95.215.58.74] helo=mta1.migadu.com) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x88JP-0000000GoBD-2Ld4 for linux-arm-kernel@lists.infradead.org; Sun, 20 Sep 2026 03:33:56 +0000 X-Envelope-To: linux-arm-kernel@lists.infradead.org DKIM-Signature: a=rsa-sha256; bh=hXLqE47HqcLGyqOng+gJY4MA1aiOWDH2fotgfictL0g=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789875232; v=1; x=1790480032; b=MjFuIBdxri6mnPIUOZ/bHRkOn9QfFFAQ/Q0tabD86fdfsLaHgHc5pFS1MJG6bPQIFl3Gca6t kDUwPfcgXw4TbXfFtT1ksq+r5VLNgYmTTo+y/m6Qe1Fm5WLBb1VtWBJjhIKxd4GXgMgK888pnSb W4ddmcOquFJ+NHn4dj3C3t4o= X-Envelope-To: linux-arm-kernel@lists.infradead.org Received: by mta10.migadu.com with ESMTPS id 15499ad898b25d57; Sun, 20 Sep 2026 03:33:52 +0000 X-Mizu-Trace-ID: 15499ad898b25d57 X-Migadu-Flow: FLOW_OUT Date: Sun, 20 Sep 2026 11:33:45 +0800 From: Baoquan He To: Mike Rapoport Cc: Wandun Chen , catalin.marinas@arm.com, will@kernel.org, chenhuacai@kernel.org, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, robh@kernel.org, saravanak@kernel.org, akpm@linux-foundation.org, pasha.tatashin@soleen.com, pratyush@kernel.org, m.szyprowski@samsung.com, mark.rutland@arm.com, kernel@xen0n.name, alex@ghiti.fr, hpa@zytor.com, ruirui.yang@linux.dev, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, kexec@lists.infradead.org, linux-mm@kvack.org, iommu@lists.linux.dev Subject: Re: [PATCH v6 06/10] memblock: introduce MEMBLOCK_NODUMP flag Message-ID: References: <20260902073116.802752-1-chenwandun1@gmail.com> <20260902073116.802752-7-chenwandun1@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260919_203355_747648_550A62A5 X-CRM114-Status: GOOD ( 18.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 09/19/26 at 10:11am, Mike Rapoport wrote: > On Fri, Sep 18, 2026 at 04:08:10PM +0800, Baoquan He wrote: > > On 09/02/26 at 03:31pm, Wandun Chen wrote: ...snip... > > > +/** > > > + * memblock_mark_nodump - Mark a memory region with flag MEMBLOCK_NODUMP. > > > + * @base: the base phys addr of the region > > > + * @size: the size of the region > > > + * > > > + * Mark the region as not to be included in crash dumps. > > > + * > > > + * Return: 0 on success, -errno on failure. > > > + */ > > > +int __init_memblock memblock_mark_nodump(phys_addr_t base, phys_addr_t size) > > ~~~~~~~~~~~~~~^ > > Is it impossible to use at runtime even thought it claims to be generic? > > This should only happen at boot. > > Allowing modifications of memblock properties in runtime is a can of worms > I don't want to open. Thank you. This is why I said this can't be claimed as a generic way to mark memory region as no dump. The generic way I'd like to see is at any time of system we can mark any unwanted memory region as no dump. And it won't impact the behaviour of the current system. > > > > +{ > > > + return memblock_setclr_flag(&memblock.memory, base, size, 1, > > > + MEMBLOCK_NODUMP); > > > +} > > > + > > > static bool should_skip_region(struct memblock_type *type, > > > struct memblock_region *m, > > > int nid, int flags) > > > @@ -2887,6 +2902,7 @@ static const char * const flagname[] = { > > > [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN", > > > [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH", > > > [ilog2(MEMBLOCK_RSRV_HUGETLB)] = "RSV_HUGETLB", > > > + [ilog2(MEMBLOCK_NODUMP)] = "NODUMP", > > > }; > > > > > > static int memblock_debug_show(struct seq_file *m, void *private) > > > -- > > > 2.43.0 > > > > > -- > Sincerely yours, > Mike.