On Sun, Jul 18, 2021 at 11:03:51PM +0200, Oleksandr Natalenko wrote: > + stable@xxxxxxxxxxxxxxx > > On neděle 18. července 2021 23:01:24 CEST Oleksandr Natalenko wrote: > > Hello. > > > > On sobota 17. července 2021 22:22:08 CEST Chris Clayton wrote: > > > I checked the output from dmesg yesterday and found the following warning: > > > > > > [Fri Jul 16 09:15:29 2021] ------------[ cut here ]------------ > > > [Fri Jul 16 09:15:29 2021] WARNING: CPU: 11 PID: 2701 at > > > kernel/rcu/tree_plugin.h:359 rcu_note_context_switch+0x37/0x3d0 [Fri Jul Could you run ./scripts/faddr2line vmlinux rcu_note_context_switch+0x37/0x3d0 > > > [Fri Jul 16 09:15:29 2021] Call Trace: > > > [Fri Jul 16 09:15:29 2021] __schedule+0x86/0x810 > > > [Fri Jul 16 09:15:29 2021] schedule+0x40/0xe0 > > > [Fri Jul 16 09:15:29 2021] io_schedule+0x3d/0x60 > > > [Fri Jul 16 09:15:29 2021] wait_on_page_bit_common+0x129/0x390 > > > [Fri Jul 16 09:15:29 2021] ? __filemap_set_wb_err+0x10/0x10 > > > [Fri Jul 16 09:15:29 2021] __lock_page_or_retry+0x13f/0x1d0 > > > [Fri Jul 16 09:15:29 2021] do_swap_page+0x335/0x5b0 > > > [Fri Jul 16 09:15:29 2021] __handle_mm_fault+0x444/0xb20 > > > [Fri Jul 16 09:15:29 2021] handle_mm_fault+0x5c/0x170 You were handling a page fault at the time. The page you wanted was on swap and this warning fired as a result of waiting for the page to come back in from swap. There are a number of warnings in that function, so it'd be good to track down exactly which one it is.