f2fs: limit # of inmemory pages
If some abnormal users try lots of atomic write operations, f2fs is able to
produce pinned pages in the main memory which affects system performance.
This patch limits that as 20% over total memory size, and if f2fs reaches
to the limit, it will drop all the inmemory pages.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 20f60f9..d571961 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -74,6 +74,10 @@ bool available_free_memory(struct f2fs_sb_info *sbi, int type)
atomic_read(&sbi->total_ext_node) *
sizeof(struct extent_node)) >> PAGE_SHIFT;
res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
+ } else if (type == INMEM_PAGES) {
+ /* it allows 20% / total_ram for inmemory pages */
+ mem_size = get_pages(sbi, F2FS_INMEM_PAGES);
+ res = mem_size < (val.totalram / 5);
} else {
if (!sbi->sb->s_bdi->wb.dirty_exceeded)
return true;
