From: Peter Zijlstra <peterz@infradead.org>
To: Avi Kivity <avi@redhat.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>,
Oleg Nesterov <oleg@redhat.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Marcelo Tosatti <mtosatti@redhat.com>,
KVM list <kvm@vger.kernel.org>
Subject: Re: [RFC][PATCH] srcu: Implement call_srcu()
Date: Tue, 31 Jan 2012 14:50:07 +0100 [thread overview]
Message-ID: <1328017807.2446.230.camel@twins> (raw)
In-Reply-To: <4F27F0E6.1040309@redhat.com>
On Tue, 2012-01-31 at 15:47 +0200, Avi Kivity wrote:
> They really need to return quickly to userspace, and they really need to
> perform some operation between rcu_assign_pointer() and returning, so no.
Bugger :/
> >
> > Compile tested only!! :-)
> >
>
> How much did synchronize_srcu_expedited() regress? Presumably your
> compiler didn't tell you that.
Nope, quite a lot I figure.
> Can we get it back to speed by scheduling a work function on all cpus?
> wouldn't that force a quiescent state and allow call_srcu() to fire?
>
> In kvm's use case synchronize_srcu_expedited() is usually called when no
> thread is in a critical section, so we don't have to wait for anything
> except the srcu machinery.
OK, I'll try and come up with means of making it go fast again ;-)
next prev parent reply other threads:[~2012-01-31 13:50 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1328016724.2446.229.camel@twins>
2012-01-31 13:47 ` [RFC][PATCH] srcu: Implement call_srcu() Avi Kivity
2012-01-31 13:50 ` Peter Zijlstra [this message]
2012-01-31 22:24 ` Paul E. McKenney
2012-02-01 10:22 ` Peter Zijlstra
2012-02-01 10:44 ` Avi Kivity
2012-02-01 10:49 ` Avi Kivity
2012-02-01 11:00 ` Takuya Yoshikawa
2012-02-01 11:01 ` Avi Kivity
2012-02-01 11:12 ` Takuya Yoshikawa
2012-02-01 13:24 ` Avi Kivity
2012-02-02 5:46 ` [test result] dirty logging without srcu update -- " Takuya Yoshikawa
2012-02-02 10:10 ` Avi Kivity
2012-02-02 10:21 ` Takuya Yoshikawa
2012-02-02 10:21 ` Avi Kivity
2012-02-02 10:40 ` Takuya Yoshikawa
2012-02-02 11:02 ` Avi Kivity
2012-02-02 14:44 ` Takuya Yoshikawa
2012-02-02 14:57 ` Avi Kivity
2012-02-01 13:43 ` Marcelo Tosatti
2012-02-01 15:42 ` Takuya Yoshikawa
2012-02-01 13:50 ` Marcelo Tosatti
2012-02-08 15:43 ` [RFC] need to improve slot creation/destruction? -- " Takuya Yoshikawa
2012-02-08 18:45 ` Marcelo Tosatti
2012-02-09 13:48 ` Takuya Yoshikawa
2012-02-09 14:25 ` Avi Kivity
2012-02-10 17:16 ` Marcelo Tosatti
2012-02-14 9:52 ` Avi Kivity
2012-02-09 14:23 ` Avi Kivity
2012-02-09 14:24 ` Avi Kivity
2012-02-10 13:08 ` Takuya Yoshikawa
2012-02-10 17:17 ` Marcelo Tosatti
2012-02-10 13:25 ` Takuya Yoshikawa
2012-02-14 9:52 ` Avi Kivity
2012-02-01 14:07 ` Paul E. McKenney
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