There are several small things to be considered regarding the
new inter-page compaction mechanism. First, we better set the
relevant size in chunks to 0 in the old z3fold header for the
object that has been moved to another z3fold page. Then, we
shouldn't do inter-page compaction if an object is mapped.
Lastly, free_handle should happen before release_z3fold_page
(but not in case the page is under reclaim, it will the handle
will be freed by reclaim then).
This patch addresses all three issues.
Signed-off-by: Vitaly Wool <vitaly.vul@xxxxxxxx>
---
mm/z3fold.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/mm/z3fold.c b/mm/z3fold.c
index 36bd2612f609..f2a75418e248 100644
--- a/mm/z3fold.c
+++ b/mm/z3fold.c
@@ -670,6 +670,7 @@ static struct z3fold_header *compact_single_buddy(struct z3fold_header *zhdr)
int first_idx = __idx(zhdr, FIRST);
int middle_idx = __idx(zhdr, MIDDLE);
int last_idx = __idx(zhdr, LAST);
+ unsigned short *moved_chunks = NULL;
/*
* No need to protect slots here -- all the slots are "local" and
@@ -679,14 +680,17 @@ static struct z3fold_header *compact_single_buddy(struct z3fold_header *zhdr)
p += ZHDR_SIZE_ALIGNED;
sz = zhdr->first_chunks << CHUNK_SHIFT;
old_handle = (unsigned long)&zhdr->slots->slot[first_idx];
+ moved_chunks = &zhdr->first_chunks;
} else if (zhdr->middle_chunks && zhdr->slots->slot[middle_idx]) {
p += zhdr->start_middle << CHUNK_SHIFT;
sz = zhdr->middle_chunks << CHUNK_SHIFT;
old_handle = (unsigned long)&zhdr->slots->slot[middle_idx];
+ moved_chunks = &zhdr->middle_chunks;
} else if (zhdr->last_chunks && zhdr->slots->slot[last_idx]) {
p += PAGE_SIZE - (zhdr->last_chunks << CHUNK_SHIFT);
sz = zhdr->last_chunks << CHUNK_SHIFT;
old_handle = (unsigned long)&zhdr->slots->slot[last_idx];
+ moved_chunks = &zhdr->last_chunks;
}
if (sz > 0) {
@@ -743,6 +747,8 @@ static struct z3fold_header *compact_single_buddy(struct z3fold_header *zhdr)
write_unlock(&zhdr->slots->lock);
add_to_unbuddied(pool, new_zhdr);
z3fold_page_unlock(new_zhdr);
+
+ *moved_chunks = 0;
}
return new_zhdr;
@@ -840,7 +846,7 @@ static void do_compact_page(struct z3fold_header *zhdr, bool locked)
}
if (!zhdr->foreign_handles && buddy_single(zhdr) &&
- compact_single_buddy(zhdr)) {
+ zhdr->mapped_count == 0 && compact_single_buddy(zhdr)) {
if (kref_put(&zhdr->refcount, release_z3fold_page_locked))
atomic64_dec(&pool->pages_nr);
else
@@ -1254,6 +1260,8 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
return;
}
+ if (!page_claimed)
+ free_handle(handle);
if (kref_put(&zhdr->refcount, release_z3fold_page_locked_list)) {
atomic64_dec(&pool->pages_nr);
return;
@@ -1263,7 +1271,6 @@ static void z3fold_free(struct z3fold_pool *pool, unsigned long handle)
z3fold_page_unlock(zhdr);
return;
}
- free_handle(handle);
if (unlikely(PageIsolated(page)) ||
test_and_set_bit(NEEDS_COMPACTING, &page->private)) {
put_z3fold_header(zhdr);
--
2.17.1
