From: Gleb Natapov <gleb@redhat.com>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>,
linux-next list <linux-next@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
paulmck@linux.vnet.ibm.com, sasha.levin@oracle.com,
avi@redhat.com
Subject: Re: [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault
Date: Tue, 27 Nov 2012 18:39:10 +0200 [thread overview]
Message-ID: <20121127163910.GL12969@redhat.com> (raw)
In-Reply-To: <CAFTL4hyfCt2imzBYW+Sn5QUAwham=ZQ2nNER5Np7Hq4yg1LzxA@mail.gmail.com>
On Tue, Nov 27, 2012 at 04:56:30PM +0100, Frederic Weisbecker wrote:
> 2012/11/27 Gleb Natapov <gleb@redhat.com>:
> > For KVM_PV_REASON_PAGE_NOT_PRESENT it behaves like an exception.
>
> Ok.
> There seem to be a bug in kvm_async_pf_task_wait(). Using
> idle_cpu(cpu) to find out if the current task is the idle task may not
> work if there is pending wake up. Me may schedule another task but
> when that other task sleeps later we can't schedule back to idle until
> the fault is completed.
>
> The right way is to use is_idle_task(current)
But if there is pending wake up then scheduling to the waked up task is
exactly what we want.
--
Gleb.
next prev parent reply other threads:[~2012-11-27 16:39 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-27 5:15 [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Li Zhong
2012-11-27 5:58 ` [PATCH rcu] use new nesting value for rcu_dyntick trace in rcu_eqs_enter_common Li Zhong
2012-11-27 15:18 ` Paul E. McKenney
2012-11-27 13:07 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to async page fault Gleb Natapov
2012-11-27 14:01 ` Sasha Levin
2012-11-27 15:25 ` Paul E. McKenney
2012-11-27 15:34 ` Frederic Weisbecker
2012-11-27 14:38 ` Frederic Weisbecker
2012-11-27 15:44 ` Gleb Natapov
2012-11-27 15:56 ` Frederic Weisbecker
2012-11-27 16:19 ` Paul E. McKenney
2012-11-27 16:48 ` Frederic Weisbecker
2012-11-27 16:59 ` Paul E. McKenney
2012-11-27 16:39 ` Gleb Natapov [this message]
2012-11-27 16:51 ` Frederic Weisbecker
2012-11-27 17:00 ` Gleb Natapov
2012-11-27 17:30 ` Frederic Weisbecker
2012-11-27 17:47 ` Gleb Natapov
2012-11-27 18:12 ` Frederic Weisbecker
2012-11-27 19:27 ` Gleb Natapov
2012-11-27 22:53 ` Frederic Weisbecker
2012-11-27 22:54 ` Frederic Weisbecker
2012-11-27 15:39 ` Frederic Weisbecker
2012-11-27 16:16 ` Paul E. McKenney
2012-11-27 16:31 ` Frederic Weisbecker
2012-11-27 16:29 ` Frederic Weisbecker
2012-11-28 8:18 ` [RFC PATCH v2] Add rcu user eqs exception hooks for " Li Zhong
2012-11-28 12:55 ` Frederic Weisbecker
2012-11-28 13:53 ` Gleb Natapov
2012-11-28 14:25 ` Frederic Weisbecker
2012-11-29 11:07 ` Gleb Natapov
2012-11-29 14:47 ` Frederic Weisbecker
2012-11-30 9:18 ` [RFC PATCH v3] " Li Zhong
2012-11-30 10:26 ` Gleb Natapov
2012-12-03 2:08 ` Li Zhong
2012-12-03 8:30 ` Gleb Natapov
2012-12-03 9:57 ` Gleb Natapov
2012-12-04 2:35 ` [ PATCH] " Li Zhong
2012-12-18 13:25 ` Gleb Natapov
2012-12-04 2:36 ` [RFC PATCH v3] " Li Zhong
2012-12-04 5:11 ` Gleb Natapov
2012-12-04 5:40 ` Li Zhong
2012-12-04 13:02 ` Gleb Natapov
2012-12-04 14:28 ` Paul E. McKenney
2012-11-29 1:49 ` [RFC PATCH v2] " Li Zhong
2012-11-29 14:40 ` Frederic Weisbecker
2012-11-29 17:25 ` Gleb Natapov
2012-11-30 8:36 ` Li Zhong
2012-11-30 10:08 ` Gleb Natapov
2012-11-27 16:43 ` [RFC PATCH] Fix abnormal rcu dynticks_nesting values related to " Frederic Weisbecker
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