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c=simple/simple; d=arm.com; s=foss; t=1774522452; bh=8IXmdtIFEytfMHYy2/zN6eUVEhDW6CUJvZu3Mba6/Z0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YVuxS70wtA+CNyc+9Yfuu8kLdwGx0hAOW4qIgVCCdqd3eWV81ySjZ1drGGhP2OXoL +ZNCcv/2wvx0wEMhP2Dp3UCFRMfOF2SBHpPH29ZkEJibdsvI0zy0/8alDG7Ivbi7i4 oE7duHHNhvv6uUVGYqsXoDVURWRztrpZN8osSmlg= Date: Thu, 26 Mar 2026 10:54:01 +0000 From: Catalin Marinas To: Jinjie Ruan Cc: corbet@lwn.net, skhan@linuxfoundation.org, will@kernel.org, chenhuacai@kernel.org, kernel@xen0n.name, maddy@linux.ibm.com, mpe@ellerman.id.au, npiggin@gmail.com, chleroy@kernel.org, pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, robh@kernel.org, saravanak@kernel.org, akpm@linux-foundation.org, bhe@redhat.com, vgoyal@redhat.com, dyoung@redhat.com, rdunlap@infradead.org, peterz@infradead.org, pawan.kumar.gupta@linux.intel.com, feng.tang@linux.alibaba.com, dapeng1.mi@linux.intel.com, kees@kernel.org, elver@google.com, paulmck@kernel.org, lirongqing@baidu.com, rppt@kernel.org, ardb@kernel.org, leitao@debian.org, osandov@fb.com, cfsworks@gmail.com, tangyouling@kylinos.cn, sourabhjain@linux.ibm.com, ritesh.list@gmail.com, eajames@linux.ibm.com, songshuaishuai@tinylab.org, kevin.brodsky@arm.com, samuel.holland@sifive.com, vishal.moola@gmail.com, junhui.liu@pigmoral.tech, coxu@redhat.com, liaoyuanhong@vivo.com, jbohac@suse.cz, fuqiang.wang@easystack.cn, guoren@kernel.org, chenjiahao16@huawei.com, hbathini@linux.ibm.com, james.morse@arm.com, takahiro.akashi@linaro.org, lizhengyu3@huawei.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, kexec@lists.infradead.org Subject: Re: [PATCH v10 6/8] arm64: kexec: Add support for crashkernel CMA reservation Message-ID: References: <20260325025904.2811960-1-ruanjinjie@huawei.com> <20260325025904.2811960-7-ruanjinjie@huawei.com> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260325025904.2811960-7-ruanjinjie@huawei.com> On Wed, Mar 25, 2026 at 10:59:02AM +0800, Jinjie Ruan wrote: > Commit 35c18f2933c5 ("Add a new optional ",cma" suffix to the > crashkernel= command line option") and commit ab475510e042 ("kdump: > implement reserve_crashkernel_cma") added CMA support for kdump > crashkernel reservation. > > Crash kernel memory reservation wastes production resources if too > large, risks kdump failure if too small, and faces allocation difficulties > on fragmented systems due to contiguous block constraints. The new > CMA-based crashkernel reservation scheme splits the "large fixed > reservation" into a "small fixed region + large CMA dynamic region": the > CMA memory is available to userspace during normal operation to avoid > waste, and is reclaimed for kdump upon crash—saving memory while > improving reliability. > > So extend crashkernel CMA reservation support to arm64. The following > changes are made to enable CMA reservation: > > - Parse and obtain the CMA reservation size along with other crashkernel > parameters. > - Call reserve_crashkernel_cma() to allocate the CMA region for kdump. > - Include the CMA-reserved ranges for kdump kernel to use. > - Exclude the CMA-reserved ranges from the crash kernel memory to > prevent them from being exported through /proc/vmcore, which is already > done in the crash core. > > Update kernel-parameters.txt to document CMA support for crashkernel on > arm64 architecture. > > Acked-by: Rob Herring (Arm) > Acked-by: Baoquan He > Acked-by: Mike Rapoport (Microsoft) > Acked-by: Ard Biesheuvel > Signed-off-by: Jinjie Ruan Acked-by: Catalin Marinas