On 08/11, Zihuan Zhang wrote: > > 在 2025/8/8 22:29, Oleg Nesterov 写道: > >On 08/07, Zihuan Zhang wrote: > >>@@ -6980,6 +6981,7 @@ void __noreturn do_task_dead(void) > >> current->flags |= PF_NOFREEZE; > >> > >> __schedule(SM_NONE); > >>+ freeze_set_default_priority(current, FREEZE_PRIORITY_NEVER); > >> BUG(); > >But this change has no effect? > > > >Firstly, this last __schedule() should not return, note the BUG() we have. > > > >Secondly, this zombie is already PF_NOFREEZE, freeze_task() will return > >false anyway. > Sorry, but in our tests with a large number of zombie tasks, returning early > reduced the overhead. Even though freeze_task() would return false for > PF_NOFREEZE, skipping the extra path still saved time in our suspend/freezer https://lore.kernel.org/all/20250707084214.GD1613200@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ Anyway the patch makes no sense in its current form, see my note about __schedule() above. Oleg.
