On 2022/5/11 12:43, Rei Yamamoto wrote: > Prevent returning a pfn outside the target zone in case that not > aligned with pageblock boundary. > Otherwise isolate_migratepages_block() would handle pages not in > the target zone. > IIUC, the sole caller isolate_migratepages will ensure the pfn won't outside the target zone. So the below code change might not be necessary. Or am I miss something ? Thanks! > Signed-off-by: Rei Yamamoto <yamamoto.rei@xxxxxxxxxxxxxx> > --- > mm/compaction.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/compaction.c b/mm/compaction.c > index fe915db6149b..de42b8e48758 100644 > --- a/mm/compaction.c > +++ b/mm/compaction.c > @@ -1858,6 +1858,8 @@ static unsigned long fast_find_migrateblock(struct compact_control *cc) > > update_fast_start_pfn(cc, free_pfn); > pfn = pageblock_start_pfn(free_pfn); > + if (pfn < cc->zone->zone_start_pfn) > + pfn = cc->zone->zone_start_pfn; > cc->fast_search_fail = 0; > found_block = true; > set_pageblock_skip(freepage); >