Messages in this thread | | | Date | Sat, 3 Sep 2011 02:08:44 +0900 | From | Tejun Heo <> | Subject | Re: [PATCH pm-freezer 1/4] cgroup_freezer: fix freezer->state setting bug in freezer_change_state() |
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Hello,
On Fri, Sep 02, 2011 at 06:58:39PM +0200, Oleg Nesterov wrote: > > This still doesn't look quite right. If the cgroup is FREEZING it should > > also call try_to_freeze_cgroup(). I think this is what's needed: > > > > if (freezer->state == CGROUP_THAWED) > > atomic_inc(&system_freezing_cnt); > > freezer->state = CGROUP_FREEZING; > > retval = try_to_freeze_cgroup(cgroup, freezer); > > This is what I mentioned before, to me this looks like a win. > > Why do we need try_to_freeze_cgroup() in this case? "for safety" > could actually mean "hide the bug" ;)
I guess it depends on the viewpoint. A simple analogy would be using WARN_ON_ONCE() instead of BUG_ON() so that the mode of failure is softer. This change isn't likely to make bugs significantly more difficult to discover so why not?
> But I agree either way. Rafael, I think 1-4 are fine, but I think > we need the simple 5/4, will send in a minute...
Can you please wait a bit? The second one was broken (missing unlock) and I made some small adjustments. Will repost soon.
Thanks.
-- tejun
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