On Mon, 14 Jun 2021 at 11:56, Thomas Lindroth <thomas.lindroth@xxxxxxxxx> wrote: > > Hi. I recently upgraded to kernel series 5.10 from 4.19 and I now get warnings like > this in dmesg: > > page:00000000e966ec4e refcount:1 mapcount:0 mapping:0000000000000000 index:0xd3414 pfn:0x14914a > flags: 0x8000000000000077(locked|referenced|uptodate|lru|active|workingset) > raw: 8000000000000077 ffffdc7f4d312b48 ffffdc7f452452c8 0000000000000000 > raw: 00000000000d3414 0000000000000000 00000001ffffffff ffff8fd080123000 > page dumped because: fuse: trying to steal weird page > > The warning in fuse_check_page() doesn't check for PG_workingset which seems to be what > trips the warning. I'm not entirely sure this is a bogus warning but there used to be > similar bogus warnings caused by a missing PG_waiters check. The PG_workingset > page flag was introduced in 4.20 which explains why I get the warning now. > > I only get the new warning if I do writes to a fuse fs (mergerfs) and at the same > time put the system under memory pressure by running many qemu VMs. AFAICT fuse is trying to steal a pagecache page from a pipe buffer created by splice(2). The page looks okay, but I have no idea what PG_workingset means in this context. Matthew, can you please help? Thanks, Miklos
