On Fri, 4 May 2018 11:11:46 +0800 Jia He <hejianet@xxxxxxxxx> wrote: > In our armv8a server(QDF2400), I noticed lots of WARN_ON caused by PAGE_SIZE > unaligned for rmap_item->address under memory pressure tests(start 20 guests > and run memhog in the host). > > ... > > In rmap_walk_ksm, the rmap_item->address might still have the STABLE_FLAG, > then the start and end in handle_hva_to_gpa might not be PAGE_SIZE aligned. > Thus it will cause exceptions in handle_hva_to_gpa on arm64. > > This patch fixes it by ignoring(not removing) the low bits of address when > doing rmap_walk_ksm. > > Signed-off-by: jia.he@xxxxxxxxxxxxxxxx I assumed you wanted this patch to be committed as From:jia.he@xxxxxxxxxxxxxxxx rather than From:hejianet@xxxxxxxxx, so I made that change. Please let me know if this was inappropriate. You can do this yourself by adding an explicit From: line to the very start of the patch's email text. Also, a storm of WARN_ONs is pretty poor behaviour. Is that the only misbehaviour which this bug causes? Do you think the fix should be backported into earlier kernels?
