On 5/25/21 1:39 PM, Olivier Langlois wrote: > On Fri, 2021-05-21 at 03:31 -0400, Olivier Langlois wrote: >> >> However, I can reproduce it at will with my real program. So as Linus >> has suggested, I'll investigate by searching where the PF_IO_WORKER is >> used. >> >> I'll keep the list updated if I discover something. >> > I think that I am about to stumble into the key to unravel the mystery > of my core dump generation issue. I am going ask you a quick question > and it is very likely to trigger an ahah moment... > > To what value is the task_struct mm field is set to for the io-wkr > threads? > > If I look in the create_io_thread() function, I can see that CLONE_VM > isn't set... It definitely should be, what kernel are you looking at? If CLONE_VM wasn't set, we'd have various issues with requests accessing user mm. -- Jens Axboe
