On 2021/12/15 3:24, Catalin Marinas wrote: > On Tue, Dec 14, 2021 at 08:07:58PM +0100, Borislav Petkov wrote: >> On Fri, Dec 10, 2021 at 02:55:25PM +0800, Zhen Lei wrote: >>> From: Chen Zhou <chenzhou10@xxxxxxxxxx> >>> >>> The lower bounds of crash kernel reservation and crash kernel low >>> reservation are different, use the consistent value CRASH_ALIGN. >> >> A big WHY is missing here to explain why the lower bound of the >> allocation range needs to be 16M and why was 0 wrong? > > I asked the same here: > > https://lore.kernel.org/r/20210224143547.GB28965@xxxxxxx > > IIRC Baoquan said that there is a 1MB reserved for x86 anyway in the > lower part, so that's equivalent in practice to starting from > CRASH_ALIGN. > > Anyway, I agree the commit log should describe this. OK, I will add the description. >