On Fri, Jun 24, 2022 at 06:21:21PM +0000, cgel.zte@xxxxxxxxx wrote: > From: Ran Xiaokai <ran.xiaokai@xxxxxxxxxx> > > All tmpfs and ramfs pages have PG_dirty bit set > once they are allocated and added to the pagecache。So pages > can not be freed from tmpfs or ramfs. So skip tmpfs and ramfs > when drop caches. Hard coding magic constants in VFS code is a bad idea. If you have numbers to justify this change (which should go into this commit log), it can be properly solved by a flag on the super block, file_system_type or even better bdi.