From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Hillf Danton <hdanton@sina.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Will Deacon <will@kernel.org>, paulmck <paulmck@kernel.org>,
Andy Lutomirski <luto@amacapital.net>,
Andrew Morton <akpm@linux-foundation.org>,
Alan Stern <stern@rowland.harvard.edu>,
Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [RFC PATCH 2/3] sched: membarrier: cover kthread_use_mm (v2)
Date: Sun, 16 Aug 2020 17:05:22 -0400 (EDT) [thread overview]
Message-ID: <833020242.9878.1597611922236.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <20200816070932.10752-1-hdanton@sina.com>
----- On Aug 16, 2020, at 3:09 AM, Hillf Danton hdanton@sina.com wrote:
> On Fri, 14 Aug 2020 12:43:57 -0400 Mathieu Desnoyers wrote:
>>
>> Given that no prior kthread use this guarantee and that it only affects
>> kthreads, adding this guarantee does not affect user-space ABI.
>
> Can you expand a bit on why kthreads like ksoftirqd have to ack the
> IPIs from Dave who's not CAP_SYS_ADMIN.
Do ksoftirqd kthreads ever use kthread_use_mm() to access user
processes' memory ? If not, then they won't be disturbed by any IPI.
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
prev parent reply other threads:[~2020-08-16 21:05 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-14 16:43 [RFC PATCH 0/3] sched: membarrier updates Mathieu Desnoyers
2020-08-14 16:43 ` [RFC PATCH 1/3] sched: fix exit_mm vs membarrier (v2) Mathieu Desnoyers
2020-08-16 15:23 ` Boqun Feng
2020-09-24 15:01 ` Mathieu Desnoyers
2020-08-14 16:43 ` [RFC PATCH 2/3] sched: membarrier: cover kthread_use_mm (v2) Mathieu Desnoyers
2020-08-16 15:29 ` Boqun Feng
2020-08-24 15:27 ` Mathieu Desnoyers
2020-08-25 2:06 ` Boqun Feng
2020-09-24 15:26 ` Mathieu Desnoyers
2020-08-14 16:43 ` [RFC PATCH 3/3] sched: membarrier: document memory ordering scenarios Mathieu Desnoyers
[not found] ` <20200816070932.10752-1-hdanton@sina.com>
2020-08-16 21:05 ` Mathieu Desnoyers [this message]
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