Hi, Zhenneng, Zhenneng Li <lizhenneng@xxxxxxxxxx> writes: > We restrict the number of pages to be migrated to no more than > HPAGE_PMD_NR or NR_MAX_BATCHED_MIGRATION, but in fact, the > number of pages to be migrated may reach 2*HPAGE_PMD_NR-1 or 2 > *NR_MAX_BATCHED_MIGRATION-1, it's not in inconsistent with the context. Yes. It's not HPAGE_PMD_NR exactly. > Please refer to the patch: 42012e0436d4(migrate_pages: restrict number > of pages to migrate in batch) > > Signed-off-by: Zhenneng Li <lizhenneng@xxxxxxxxxx> > --- > mm/migrate.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index 781979567f64..7a4b37aac9e8 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1961,7 +1961,7 @@ int migrate_pages(struct list_head *from, new_folio_t get_new_folio, > break; > } > if (nr_pages >= NR_MAX_BATCHED_MIGRATION) > - list_cut_before(&folios, from, &folio2->lru); > + list_cut_before(&folios, from, &folio->lru); If the first entry of the list "from" is a THP with size HPAGE_PMD_NR, "folio" will be the first entry of from, so that "folios" will be empty. Right? > else > list_splice_init(from, &folios); > if (mode == MIGRATE_ASYNC) -- Best Regards, Huang, Ying
