Messages in this thread | | | Date | Sat, 16 Feb 2013 18:05:45 +0100 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK |
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On 02/16, Mandeep Singh Baines wrote: > > We don't need to call freezer_do_not_count() for in-kernel users > of CLONE_VFORK since exec will get called in bounded time. > > We don't want to call freezer_count() for in-kernel users because > they may be holding locks. freezer_count() calls try_to_freeze(). > We don't want to freeze an in-kernel user because it may be > holding locks.
I can only repeat my question ;)
Who? We should not do this anyway. And __call_usermodehelper() doesn't afaics.
OK, its caller (process_one_work) does lock_map_acquire() for debugging purposes, this can "confuse" print_held_locks_bug(). But this thread is PF_NOFREEZE ?
Previously this was needed to suppress the false positive. Now that 2/5 checks PF_NOFREEZE, why do we need this change?
> @@ -722,9 +722,11 @@ static int wait_for_vfork_done(struct task_struct *child, > { > int killed; > > - freezer_do_not_count(); > + if (!(current->flags & PF_KTHREAD)) > + freezer_do_not_count();
If I missed something and we really need this, imho this needs a comment.
Oleg.
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