Re: [PATCH] mm/shmem: Do not wait for lock_page() in shmem_unused_huge_shrink()

On Fri, Mar 16, 2018 at 10:14:24PM +0900, Tetsuo Handa wrote:

f2fs is doing

page = f2fs_pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0);

which calls

struct page *pagecache_get_page(inode->i_mapping, 0, FGP_LOCK|FGP_NOWAIT, 0);

. Then, can't we define

static inline struct page *find_trylock_page(struct address_space *mapping, pgoff_t offset) { return pagecache_get_page(mapping, offset, FGP_LOCK|FGP_NOWAIT, 0); }

and replace find_lock_page() with find_trylock_page() ?

This won't work in this case. We need to destinct no-page-in-page-cache from failed-to-lock-page. We take different routes depending on this.