On 2024/8/7 0:59, Catalin Marinas wrote: > On Tue, Aug 06, 2024 at 07:33:20PM +0800, Jinjie Ruan wrote: >> Since commit 282c3a66b724 ("crash: Fix riscv64 crash memory reserve dead >> loop"), if reservation from the high memory failed on ARM64, the kernel >> will not falls back to searching the low memory, so remove it in the doc. > > This commit doesn't exist in -next. I found it with a different hash but > don't add it in the commit log here. > >> diff --git a/Documentation/arch/arm64/kdump.rst b/Documentation/arch/arm64/kdump.rst >> index 56a89f45df28..11b9b84bf422 100644 >> --- a/Documentation/arch/arm64/kdump.rst >> +++ b/Documentation/arch/arm64/kdump.rst >> @@ -79,10 +79,6 @@ To reserve memory for crashkernel=size,high, searching is first >> attempted from the high memory region. If the reservation succeeds, the >> low memory reservation will be done subsequently. >> >> -If reservation from the high memory failed, the kernel falls back to >> -searching the low memory with the specified size in crashkernel=,high. >> -If it succeeds, no further reservation for low memory is needed. > > I recall long discussions over a year ago where the conclusion was that > for sysadmins it's easier to have crashkernel=,high the default with > fallback to lowmem. No need to worry about how much low or high memory > there is on a SoC, just specify a preference for high memory. > > Can we not have a different fix for the infinite loop problem while we > preserve the fallback behaviour? Of course, thank you! >