From: Tejun Heo <tj@kernel.org>
To: Aleksa Sarai <cyphar@cyphar.com>
Cc: lizefan@huawei.com, mingo@redhat.com, peterz@infradead.org,
richard@nod.at, "Frédéric Weisbecker" <fweisbec@gmail.com>,
linux-kernel@vger.kernel.org, cgroups@vger.kernel.org
Subject: Re: [PATCH v2 1/2] cgroups: allow a cgroup subsystem to reject a fork
Date: Wed, 11 Mar 2015 07:46:46 -0400 [thread overview]
Message-ID: <20150311114646.GC25944@htj.duckdns.org> (raw)
In-Reply-To: <CAOviyajuq5QgwmByVzF34RVyRs+fad=82i2pJH12y1kB5X6bWg@mail.gmail.com>
On Wed, Mar 11, 2015 at 04:16:30PM +1100, Aleksa Sarai wrote:
> We know that the task will have its css_set set to task_css_set(current), and
> we could just use that in cgroup_can_fork(). The only question is, can
> task_css_set(current) change between cgroup_can_fork() and cgroup_post_fork()?
Yes, that's what I've been writing in the previous messages. It can change.
> If it can change between the two calls, then we're in trouble -- there'd be no
> reliable way of checking that the future css_set allows for the fork without
> going through the registration of the css_set *proper* in cgroup_post_fork()
> unless we hold css_set_rwsem for the entirety of the can_fork() to post_fork()
> segment (which I can't imagine is a good idea).
Please re-read my previous messages.
Thanks.
--
tejun
next prev parent reply other threads:[~2015-03-11 11:46 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-23 3:08 [PATCH RFC 0/2] add nproc cgroup subsystem Aleksa Sarai
2015-02-23 3:08 ` [PATCH RFC 1/2] cgroups: allow a cgroup subsystem to reject a fork Aleksa Sarai
2015-02-23 14:49 ` Peter Zijlstra
2015-02-23 3:08 ` [PATCH RFC 2/2] cgroups: add an nproc subsystem Aleksa Sarai
[not found] ` <1424660891-12719-1-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-02-27 4:17 ` [RFC PATCH v2 0/2] add nproc cgroup subsystem Aleksa Sarai
[not found] ` <1425010639-16492-1-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-02-27 4:17 ` [PATCH v2 1/2] cgroups: allow a cgroup subsystem to reject a fork Aleksa Sarai
[not found] ` <1425010639-16492-2-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-03-09 3:06 ` Tejun Heo
[not found] ` <CAOviyaip7Faz98YWzGoTaXGYVb72sfD+ZL4Xa89reU9+=43jFA@mail.gmail.com>
[not found] ` <20150309065902.GP13283@htj.duckdns.org>
[not found] ` <20150309065902.GP13283-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-03-10 8:19 ` Aleksa Sarai
[not found] ` <CAOviyaj3mf66ho15WrD8qB=ECxKWYTAkWodxWaFVMWeZG4d0FQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-10 12:47 ` Tejun Heo
[not found] ` <20150310124701.GB28730-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-03-10 14:51 ` Aleksa Sarai
[not found] ` <CAOviyai7yJrbGb+uYpK35tw7R-KM0jWQ-BmhpyTqnRFJsVYdUA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-10 15:17 ` Tejun Heo
2015-03-11 5:16 ` Aleksa Sarai
2015-03-11 11:46 ` Tejun Heo [this message]
2015-03-11 23:47 ` Aleksa Sarai
[not found] ` <CAOviyaj55Yqahz75Gy5=yjFteeKFp7746=80-Ufww2E62Ads_Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-12 1:25 ` Tejun Heo
2015-02-27 4:17 ` [PATCH v2 2/2] cgroups: add an nproc subsystem Aleksa Sarai
[not found] ` <1425010639-16492-3-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-03-02 15:22 ` Tejun Heo
[not found] ` <20150302152205.GC17694-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-03-09 1:49 ` Zefan Li
[not found] ` <54FCFC39.6050900-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2015-03-09 2:34 ` Tejun Heo
2015-03-06 1:45 ` [PATCH v4 0/2] cgroup: add pids subsystem Aleksa Sarai
2015-03-06 1:45 ` [PATCH v4 1/2] cgroups: allow a cgroup subsystem to reject a fork Aleksa Sarai
[not found] ` <1425606357-6337-1-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-03-06 1:45 ` [PATCH v4 2/2] cgroups: add a pids subsystem Aleksa Sarai
[not found] ` <1425606357-6337-3-git-send-email-cyphar-gVpy/LI/lHzQT0dZR+AlfA@public.gmane.org>
2015-03-09 3:34 ` Tejun Heo
[not found] ` <20150309033405.GE13283-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-03-09 3:39 ` Tejun Heo
2015-03-09 18:58 ` Austin S Hemmelgarn
[not found] ` <54FDED43.4050908-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-09 19:51 ` Tejun Heo
2015-03-10 8:10 ` Aleksa Sarai
2015-03-10 11:32 ` Austin S Hemmelgarn
[not found] ` <54FED651.6040100-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-10 12:31 ` Aleksa Sarai
[not found] ` <CAOviyagpCNcAN4hdhsxffdpE+yDmw+NXx+FikTe64GJ1hQeXhQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-11 15:13 ` Austin S Hemmelgarn
[not found] ` <55005BAC.9060405-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-12 2:28 ` Aleksa Sarai
2015-03-12 15:35 ` Austin S Hemmelgarn
2015-03-12 3:47 ` Tejun Heo
2015-03-09 3:08 ` [PATCH v4 0/2] cgroup: add " Tejun Heo
2015-02-27 11:49 ` [PATCH RFC 0/2] add nproc cgroup subsystem Tejun Heo
[not found] ` <20150227114940.GB3964-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-02-27 13:46 ` Richard Weinberger
[not found] ` <54F07525.4050100-/L3Ra7n9ekc@public.gmane.org>
2015-02-27 13:52 ` Tejun Heo
2015-02-27 16:42 ` Austin S Hemmelgarn
[not found] ` <54F09E62.8000007-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-02-27 17:06 ` Tejun Heo
[not found] ` <20150227170640.GK3964-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-02-27 17:25 ` Tim Hockin
2015-02-27 17:45 ` Tejun Heo
[not found] ` <20150227174503.GM3964-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-02-27 17:56 ` Tejun Heo
2015-02-27 21:45 ` Tim Hockin
2015-02-27 21:49 ` Tejun Heo
[not found] ` <CAAAKZwsCc8BtFx58KMFpRTohU81oCBeGVOPGMJrjJt9q5upKfQ@mail.gmail.com>
2015-02-28 16:57 ` Tejun Heo
[not found] ` <20150228165706.GS3964-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-02-28 22:26 ` Tim Hockin
[not found] ` <CAAAKZwv=idxvrffHx2QyW=PGH4k42ckq-VLJGQrXkeQ6NmByRQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-02-28 22:50 ` Tejun Heo
[not found] ` <20150228225036.GA4597-piEFEHQLUPpN0TnZuCh8vA@public.gmane.org>
2015-03-01 4:46 ` Tim Hockin
2015-02-28 23:11 ` Johannes Weiner
2015-02-27 18:49 ` Austin S Hemmelgarn
[not found] ` <54F0BC51.4050506-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-02-27 19:35 ` Tejun Heo
2015-02-28 9:26 ` Aleksa Sarai
[not found] ` <CAOviyajSOY6kTiwTA+APf9VGT=Ui=0QQH6KUqwaxHB3ahuJk2g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-02-28 11:59 ` Tejun Heo
[not found] ` <CAAAKZws45c3PhFQMGrm_K+OZV+KOyGV9sXTakHcTfNP1kHxzOQ@mail.gmail.com>
[not found] ` <CAAAKZws45c3PhFQMGrm_K+OZV+KOyGV9sXTakHcTfNP1kHxzOQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-02-28 16:43 ` Tejun Heo
2015-03-02 13:13 ` Austin S Hemmelgarn
[not found] ` <54F461F3.3030903-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
2015-03-02 13:31 ` Aleksa Sarai
[not found] ` <CAOviyahKJthwLTND51HhaRNB_KJC60T7HFHjdqPZf3pQmAUAhw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-03-02 13:54 ` Tejun Heo
2015-03-02 13:49 ` Tejun Heo
2015-02-27 17:12 ` Tim Hockin
[not found] ` <CAO_RewbeTbMuqVG5wsui_gHwrdgqjF0KLk6yr5a3bb76VOkofg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2015-02-27 17:15 ` Tejun Heo
2015-03-04 20:23 ` [PATCH v3 0/2] cgroup: add pids subsystem Aleksa Sarai
2015-03-04 20:23 ` [PATCH v3 1/2] cgroups: allow a cgroup subsystem to reject a fork Aleksa Sarai
2015-03-04 20:23 ` [PATCH v3 2/2] cgroups: add a pids subsystem Aleksa Sarai
2015-03-05 8:39 ` Aleksa Sarai
2015-03-05 14:37 ` Marian Marinov
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