From: Coly Li <colyli@xxxxxxx> To explain the pages allocated from mempool state->pool can be swapped in __btree_sort(), because state->pool is a page pool, which allocates pages by alloc_pages() indeed. Signed-off-by: Coly Li <colyli@xxxxxxx> --- drivers/md/bcache/bset.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c index cffcdc9feefb..4385303836d8 100644 --- a/drivers/md/bcache/bset.c +++ b/drivers/md/bcache/bset.c @@ -1257,6 +1257,11 @@ static void __btree_sort(struct btree_keys *b, struct btree_iter *iter, * Our temporary buffer is the same size as the btree node's * buffer, we can just swap buffers instead of doing a big * memcpy() + * + * Don't worry event 'out' is allocated from mempool, it can + * still be swapped here. Because state->pool is a page mempool + * creaated by by mempool_init_page_pool(), which allocates + * pages by alloc_pages() indeed. */ out->magic = b->set->data->magic; -- 2.16.4
