In that case, we should adjust nr_reserved_highatomic.
Otherwise, VM cannot reserve highorderatomic pageblocks any more
although it doesn't reach 1% limit. It means highorder atomic
allocation failure would be higher.
So, this patch decreases the account as well as migratetype
if it was MIGRATE_HIGHATOMIC.
Signed-off-by: Minchan Kim <minchan@xxxxxxxxxx>
Hm wouldn't it be simpler just to prevent the pageblock's migratetype to be
changed if it's highatomic? Possibly also not do move_freepages_block() in
It could be. Actually, I did it with modifying can_steal_fallback which returns
false it found the pageblock is highorderatomic but changed to this way again
because I don't have any justification to prevent changing pageblock.
If you give concrete justification so others isn't against on it, I am happy to
do what you suggested.