From: Oleg Nesterov <oleg@redhat.com>
To: Mandeep Singh Baines <msb@chromium.org>
Cc: linux-kernel@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Rafael J. Wysocki" <rjw@sisk.pl>, Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK
Date: Fri, 15 Feb 2013 16:28:40 +0100 [thread overview]
Message-ID: <20130215152840.GC30829@redhat.com> (raw)
In-Reply-To: <1360885096-21207-1-git-send-email-msb@chromium.org>
On 02/14, 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.
OK,
> We don't want to call freezer_count() for in-kernel users because
> they may be holding locks.
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 ?
> @@ -722,9 +722,11 @@ static int wait_for_vfork_done(struct task_struct *child,
> {
> int killed;
>
> - freezer_do_not_count();
> + if (current->mm)
> + freezer_do_not_count();
And if you want to exclude in-kernel users, then perhaps PF_KTHREAD check
will look a bit better.
Oleg.
next prev parent reply other threads:[~2013-02-15 15:30 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-14 23:38 [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK Mandeep Singh Baines
2013-02-14 23:38 ` [PATCH 2/5] lockdep: check that no locks held at freeze time Mandeep Singh Baines
2013-02-15 11:16 ` Ingo Molnar
2013-02-15 15:44 ` Oleg Nesterov
2013-02-14 23:38 ` [PATCH 3/5] coredump: cleanup the waiting for coredump_finish code Mandeep Singh Baines
2013-02-15 14:53 ` Oleg Nesterov
2013-02-15 23:30 ` Andrew Morton
2013-02-14 23:38 ` [PATCH 4/5] coredump: use a freezable_schedule for the coredump_finish wait Mandeep Singh Baines
2013-02-14 23:38 ` [PATCH 5/5] coredump: abort core dump piping only due to a fatal signal Mandeep Singh Baines
2013-02-15 15:01 ` Oleg Nesterov
2013-02-16 1:20 ` Mandeep Singh Baines
2013-02-16 17:05 ` Oleg Nesterov
2013-02-15 23:25 ` Andrew Morton
2013-02-16 0:09 ` [PATCH v3] coredump: ignore non-fatal signals when core dumping to a pipe Mandeep Singh Baines
2013-02-16 0:57 ` [PATCH v4] " Mandeep Singh Baines
2013-02-15 15:28 ` Oleg Nesterov [this message]
-- strict thread matches above, loose matches on Subject: below --
2013-02-16 9:53 [PATCH 1/5] vfork: don't freezer_count() for in-kernel users of CLONE_VFORK Mandeep Singh Baines
2013-02-16 17:05 ` Oleg Nesterov
2013-02-20 0:07 ` Mandeep Singh Baines
2013-02-20 1:41 ` Mandeep Singh Baines
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