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Mon, 21 Sep 2026 05:52:26 +0000 X-Mizu-Trace-ID: 3106e5e1082e60f1 X-Migadu-Flow: FLOW_OUT Date: Mon, 21 Sep 2026 13:52:24 +0800 From: Baoquan He To: Wandun Cc: Mike Rapoport , 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> <32b00102-0961-49e3-b780-74d6db182809@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <32b00102-0961-49e3-b780-74d6db182809@gmail.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: F3C1C180004 X-Stat-Signature: auy6kibw68joc8si54tqkjoudkaa97xs X-Rspam-User: X-HE-Tag: 1789969948-184120 X-HE-Meta: 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 ZJ/HSO9n ndO9mlhIm/TVuf+iA9S6c1/RDItBWdkImsN4CEDgvi6KqKdPg+rWmFR4Q95qKWuRQGdr1tavJwhQkboFEzd7TiYXAUd7y7SRvbGmtaDUCdh5sf5gn5Fw4av6pGI6yS3+Ae5bkVKse2NlQMhLBYyHy3qFP3Be6Vfx9CY4ISDv52kwjtBo6boo0Ab87kQjhhrPL+WpF/5+493y0N7S34wWcQ8VFB6SVHXOzU22S0swU6CNe1CXCBbBErca+iGc9RFrqqCYBWo8l5vQx3XFfSoQCgqGFmsdQFmfBqXWveZxSv7D9VGz+QnjIujZkrtuG1r2ZB7ZT Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 09/20/26 at 04:00pm, Wandun wrote: > > > On 9/20/26 11:33, Baoquan He wrote: > > 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. > > Thanks Mike for the explanation and Baoquan for the suggestion. > I'll drop the "generic" related description in the next version. > > > Baoquan, by the way, patch 2 is still awaiting review. It rewrites > the riscv side of the code that patch 3 (which you've acked) then > folds into the weak defaults, if you could take a look at it too, > that would be very helpful. I checked and looks good, I have added ACK. While RISC-V people can hold it anytime if they have concern.