For CMA balancing, the compaction migration hooks can largely be reused, except a different function to isolate free pages is needed. So, add a pointer to the isolation function in the compact_control structure. If it's not NULL, use it, else use isolate_freepages as usual. No functional change. Signed-off-by: Frank van der Linden --- mm/compaction.c | 5 ++++- mm/internal.h | 5 +++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/mm/compaction.c b/mm/compaction.c index bf021b31c7ec..6a2c06e356c5 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1813,7 +1813,10 @@ static struct folio *compaction_alloc_noprof(struct folio *src, unsigned long da if (start_order == NR_PAGE_ORDERS) { if (has_isolated_pages) return NULL; - isolate_freepages(cc); + if (cc->isolate_freepages) + cc->isolate_freepages(cc); + else + isolate_freepages(cc); has_isolated_pages = true; goto again; } diff --git a/mm/internal.h b/mm/internal.h index 45b725c3dc03..7916d8be8922 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -873,6 +873,11 @@ struct compact_control { unsigned int nr_freepages; /* Number of isolated free pages */ unsigned int nr_migratepages; /* Number of pages to migrate */ unsigned long free_pfn; /* isolate_freepages search base */ + /* + * Function to use to isolate free pages, if applicable. If NULL, + * default to isolate_freepages(). + */ + void (*isolate_freepages)(struct compact_control *cc); /* * Acts as an in/out parameter to page isolation for migration. * isolate_migratepages uses it as a search base. -- 2.51.0.384.g4c02a37b29-goog