From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-63.mta0.migadu.com [91.218.175.63]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C41452D8762 for ; Fri, 18 Sep 2026 08:08:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.63 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789718899; cv=none; b=qSzpc0si1xBD1YQ8ehDPm4PYGisH53pbbudPlviNi4nHLcVYaDI3Ljj6bm9Rh8lPrjb5iyWOslIOY3iAdRc7F3LTqWVmMnRKpzQOKyDtx1K9/dyWRM1iYqWh2zXZbwWq4uGw0JcRqjwVKgKr0gn1IyzR3vzM8hho26zo05dISuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789718899; c=relaxed/simple; bh=xyISkBw574ZsXxKvu3xwdAxcFPyzjbZIs1ckRKr/QYs=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=k6z9u0F0cgyB11wQTBwy6ZVcHzYRQT/72/HdYKbqJG3McMrV6wVisP7Bu8pYYYYyBVKFBysROpXtcdnVIM/5WrUkCXui6G1X2woVDjUKy79EfH1AoryNx2IM43Njq2BIP5hyLP8Ee2+A9AHuYkUMp1tkFOOmo4kZIVksiolV7jI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=GYOIjE9T; arc=none smtp.client-ip=91.218.175.63 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="GYOIjE9T" X-Envelope-To: linux-kernel@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=xyISkBw574ZsXxKvu3xwdAxcFPyzjbZIs1ckRKr/QYs=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1789718893; v=1; x=1790323693; b=GYOIjE9TCS52kB3fasEHvocV/8o9kyickSQMkR89NrjEqDrcRo7nQvB/cqQnO+0Tj5dPpoTG nBygKi9DiR9Q8JDpWZYaeMzZhRwyJr700RwTNBDgmq+K6LMw5VsDWStD4oF15tqYBf9N6CpOzZE iQwloIBn/uTyOTtX1ltiWxJE= X-Envelope-To: linux-kernel@vger.kernel.org Received: by mta10.migadu.com with ESMTPS id e05f79cdbbeb581e; Fri, 18 Sep 2026 08:08:13 +0000 X-Mizu-Trace-ID: e05f79cdbbeb581e X-Migadu-Flow: FLOW_OUT Date: Fri, 18 Sep 2026 16:08:10 +0800 From: Baoquan He To: Wandun Chen Cc: 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, rppt@kernel.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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260902073116.802752-7-chenwandun1@gmail.com> On 09/02/26 at 03:31pm, Wandun Chen wrote: > From: Wandun Chen > > Add MEMBLOCK_NODUMP to mark regions that should be excluded from > kdump vmcores. > > The flag is meant for reserved memory that carries no data useful for > crash analysis. Reusable reserved regions such as CMA may hold useful > data, so these regions must not be marked MEMBLOCK_NODUMP. Subsequent > patches wire this up for /reserved-memory and /memreserve/ entries. > > Suggested-by: Rob Herring > Signed-off-by: Wandun Chen > Tested-by: Meijing Zhao > --- > include/linux/memblock.h | 9 +++++++++ > mm/memblock.c | 16 ++++++++++++++++ > 2 files changed, 25 insertions(+) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index d62db9e776cf..b2fcf11fba2b 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -52,6 +52,8 @@ extern unsigned long long max_possible_pfn; > * kernel that we know is good to use. It is the only memory that > * allocations may happen from in this phase. > * @MEMBLOCK_RSRV_HUGETLB: memory is reserved for hugetlb pages > + * @MEMBLOCK_NODUMP: exclude from kdump vmcore. It carries no data useful > + * for crash analysis (e.g. firmware carveouts). > */ > enum memblock_flags { > MEMBLOCK_NONE = 0x0, /* No special request */ > @@ -63,6 +65,7 @@ enum memblock_flags { > MEMBLOCK_RSRV_KERN = 0x20, /* memory reserved for kernel use */ > MEMBLOCK_KHO_SCRATCH = 0x40, /* scratch memory for kexec handover */ > MEMBLOCK_RSRV_HUGETLB = 0x80, /* memory reserved for hugetlb pages */ > + MEMBLOCK_NODUMP = 0x100,/* exclude from kdump vmcore */ > }; > > /** > @@ -160,6 +163,7 @@ int memblock_reserved_mark_noinit(phys_addr_t base, phys_addr_t size); > int memblock_reserved_mark_kern(phys_addr_t base, phys_addr_t size); > int memblock_mark_kho_scratch(phys_addr_t base, phys_addr_t size); > int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size); > +int memblock_mark_nodump(phys_addr_t base, phys_addr_t size); > > void memblock_free(void *ptr, size_t size); > void reset_all_zones_managed_pages(void); > @@ -306,6 +310,11 @@ static inline bool memblock_is_kho_scratch(struct memblock_region *m) > return m->flags & MEMBLOCK_KHO_SCRATCH; > } > > +static inline bool memblock_is_nodump(struct memblock_region *m) > +{ > + return m->flags & MEMBLOCK_NODUMP; > +} > + > int memblock_search_pfn_nid(unsigned long pfn, unsigned long *start_pfn, > unsigned long *end_pfn); > void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, > diff --git a/mm/memblock.c b/mm/memblock.c > index f2952d725c10..2e87f39826dd 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -1204,6 +1204,21 @@ __init int memblock_clear_kho_scratch(phys_addr_t base, phys_addr_t size) > MEMBLOCK_KHO_SCRATCH); > } > > +/** > + * 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? > +{ > + 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 >