From mboxrd@z Thu Jan 1 00:00:00 1970 From: Baoquan He Date: Thu, 17 Mar 2022 10:38:38 +0800 Subject: [PATCH v21 3/5] arm64: kdump: reimplement crashkernel=X In-Reply-To: <20220227030717.1464-4-thunder.leizhen@huawei.com> References: <20220227030717.1464-1-thunder.leizhen@huawei.com> <20220227030717.1464-4-thunder.leizhen@huawei.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: kexec@lists.infradead.org On 02/27/22 at 11:07am, Zhen Lei wrote: > From: Chen Zhou > > There are following issues in arm64 kdump: > 1. We use crashkernel=X to reserve crashkernel below 4G, which > will fail when there is no enough low memory. > 2. If reserving crashkernel above 4G, in this case, crash dump > kernel will boot failure because there is no low memory available ~~ change it to "get boot failure" or "fail to boot" > for allocation. > > To solve these issues, change the behavior of crashkernel=X and > introduce crashkernel=X,[high,low]. crashkernel=X tries low allocation > in DMA zone, and fall back to high allocation if it fails. > We can also use "crashkernel=X,high" to select a region above DMA zone, > which also tries to allocate at least 256M in DMA zone automatically. > "crashkernel=Y,low" can be used to allocate specified size low memory. > > Signed-off-by: Chen Zhou > Co-developed-by: Zhen Lei > Signed-off-by: Zhen Lei