From: Tejun Heo <htejun@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>,
zhang.yi20@zte.com.cn, lkml <linux-kernel@vger.kernel.org>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child
Date: Thu, 28 Nov 2013 09:51:15 -0500 [thread overview]
Message-ID: <20131128145115.GF3925@htj.dyndns.org> (raw)
In-Reply-To: <20131128144714.GV10022@twins.programming.kicks-ass.net>
On Thu, Nov 28, 2013 at 03:47:14PM +0100, Peter Zijlstra wrote:
> Bah, windows mentality of we know better.
>
> If they do stupid they get stupid; the only thing we should be concerned
> about is correctness, they shouldn't be able to crash the system.
It isn't about that we know better but more that we do not want to
leak implementation details to userland. "Whatever isn't crashing is
okay" doesn't work because we aren't supposed to change behaviors
which are depended upon from userland. Unless what's exposed is
actively managed, we end up being locked into specific unintended
characteristics of the current implementation. It hurts both the
kernel and userland. We end up having to hack around silly
constraints in the future and userland gets surprised when such hacks
inevitably falls apart in corner cases.
So, no, it's not about which part knows better or windows mentaility.
It's about having proper separation between implementation details and
exposed interface.
Thanks.
--
tejun
next prev parent reply other threads:[~2013-11-28 14:51 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-14 1:51 kmod: " zhang.yi20
2013-11-14 5:23 ` Tejun Heo
2013-11-14 11:40 ` Oleg Nesterov
2013-11-14 11:55 ` [PATCH 0/1]: (Was: kmod: avoid propagating PF_NO_SETAFFINITY into userspace child) Oleg Nesterov
2013-11-14 11:56 ` [PATCH 1/1] workqueue: swap set_cpus_allowed_ptr() and PF_NO_SETAFFINITY Oleg Nesterov
2013-11-22 23:13 ` Tejun Heo
[not found] ` <OF36E72FA9.51146BE3-ON48257C2E.0008BC6D-48257C2E.0008FF9C@zte.com.cn>
2013-11-25 12:14 ` 答复: " Oleg Nesterov
2013-11-26 2:10 ` [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child zhang.yi20
2013-11-26 18:04 ` Oleg Nesterov
2013-11-27 2:07 ` zhang.yi20
2013-11-27 13:20 ` Oleg Nesterov
2013-11-27 18:31 ` Tejun Heo
2013-11-28 9:13 ` Peter Zijlstra
2013-11-28 11:45 ` Oleg Nesterov
2013-11-28 12:17 ` Peter Zijlstra
2013-11-28 13:31 ` Oleg Nesterov
2013-11-28 13:39 ` Peter Zijlstra
2013-11-28 14:13 ` Tejun Heo
2013-11-28 14:31 ` Peter Zijlstra
2013-11-28 14:38 ` Tejun Heo
2013-11-28 14:47 ` Peter Zijlstra
2013-11-28 14:51 ` Tejun Heo [this message]
2013-11-28 14:55 ` Peter Zijlstra
2013-11-28 14:57 ` Tejun Heo
2013-11-28 14:59 ` Peter Zijlstra
2013-11-28 15:07 ` Tejun Heo
2013-11-28 15:17 ` Peter Zijlstra
2013-11-28 15:39 ` Tejun Heo
2013-11-28 16:33 ` Peter Zijlstra
2013-11-29 14:33 ` Tejun Heo
2013-11-28 15:47 ` Oleg Nesterov
2013-11-28 16:07 ` Oleg Nesterov
2013-11-28 14:43 ` Peter Zijlstra
2013-11-28 14:53 ` Tejun Heo
2013-11-28 14:57 ` Peter Zijlstra
2013-11-28 15:02 ` Tejun Heo
2013-11-28 15:07 ` Peter Zijlstra
2013-11-28 15:10 ` Tejun Heo
2013-11-28 15:18 ` Peter Zijlstra
2013-11-28 14:38 ` Peter Zijlstra
2013-11-28 14:45 ` Tejun Heo
2013-11-28 14:53 ` Peter Zijlstra
2013-11-28 15:34 ` Oleg Nesterov
2013-11-28 15:40 ` Peter Zijlstra
2013-11-28 16:20 ` Oleg Nesterov
2013-11-28 16:38 ` Peter Zijlstra
2013-11-28 18:13 ` Oleg Nesterov
2013-11-28 14:23 ` Oleg Nesterov
2013-11-28 14:31 ` Tejun Heo
2013-11-28 15:00 ` Oleg Nesterov
2013-11-28 15:02 ` Peter Zijlstra
2013-11-28 19:33 ` [PATCH 0/1] usermodehelper: kill ____call_usermodehelper()->set_cpus_allowed_ptr() Oleg Nesterov
2013-11-28 19:33 ` [PATCH 1/1] " Oleg Nesterov
2013-11-29 13:44 ` Tejun Heo
2013-11-29 16:49 ` Oleg Nesterov
2013-12-05 14:21 ` Frederic Weisbecker
2013-12-05 14:37 ` Oleg Nesterov
2013-12-05 14:39 ` Tejun Heo
2013-12-05 15:30 ` Oleg Nesterov
2013-12-05 19:13 ` Christoph Lameter
2013-12-06 14:53 ` Oleg Nesterov
2013-12-06 15:37 ` Christoph Lameter
2013-12-06 15:56 ` Oleg Nesterov
2013-12-05 16:26 ` Frederic Weisbecker
2013-12-05 14:42 ` Frederic Weisbecker
2013-11-28 13:41 ` [PATCH]: exec: avoid propagating PF_NO_SETAFFINITY into userspace child Peter Zijlstra
2013-11-28 14:05 ` Tejun Heo
2013-11-28 14:34 ` Oleg Nesterov
2013-11-29 9:19 zhang.yi20
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