On 18/07/2021 22:22, Matthew Wilcox wrote: > 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 > $ ./scripts/faddr2line vmlinux rcu_note_context_switch+0x37/0x3d0 rcu_note_context_switch+0x37/0x3d0: rcu_note_context_switch at ??:? >>>> [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. >