From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Jan Beulich <JBeulich@novell.com>
Cc: "mingo@elte.hu" <mingo@elte.hu>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
Ky Srinivasan <KSrinivasan@novell.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>
Subject: Re: [PATCH 2/4, v2] x86: enlightenment for ticket spin locks - Xen implementation
Date: Wed, 30 Jun 2010 16:42:18 +0200 [thread overview]
Message-ID: <4C2B57CA.3070807@goop.org> (raw)
In-Reply-To: <4C2B72950200007800008DBA@vpn.id2.novell.com>
On 06/30/2010 04:36 PM, Jan Beulich wrote:
> Are we perhaps talking about different things? I'm referring to
>
> static __always_inline void arch_spin_unlock(struct arch_spinlock *lock)
> {
> PVOP_VCALL1(pv_lock_ops.spin_unlock, lock);
> }
>
> which is an indirect call which, as I understand it, gets replaced
> with a direct one at runtime. But it remains to be a call (as opposed
> to being a single inc instructions without CONFIG_PARAVIRT_SPINLOCKS).
>
Sorry, I'm referring to pv ticketlocks, not the current
PARAVIRT_SPINLOCKS code. I agree the current PARAVIRT_SPINLOCKS
implementation is suboptimal and needs to be replaced with something
that's only called on the slow path. I just think the existing
paravirt_ops mechanism can be used to implement it rather than adding
something new.
J
next prev parent reply other threads:[~2010-06-30 14:42 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-06-29 14:32 [PATCH 2/4, v2] x86: enlightenment for ticket spin locks - Xen implementation Jan Beulich
2010-06-30 8:05 ` Peter Zijlstra
2010-06-30 8:52 ` Jan Beulich
2010-06-30 8:56 ` Peter Zijlstra
2010-06-30 9:04 ` Jan Beulich
2010-06-30 10:07 ` Jeremy Fitzhardinge
2010-06-30 11:31 ` Jan Beulich
2010-06-30 13:23 ` Jeremy Fitzhardinge
2010-06-30 14:03 ` Jan Beulich
2010-06-30 14:25 ` Jeremy Fitzhardinge
2010-06-30 14:36 ` Jan Beulich
2010-06-30 14:42 ` Jeremy Fitzhardinge [this message]
2010-06-30 22:14 ` H. Peter Anvin
2010-07-05 23:12 ` Jeremy Fitzhardinge
2010-06-30 15:57 ` Stefano Stabellini
2010-07-01 7:57 ` Jan Beulich
2010-07-01 11:39 ` Stefano Stabellini
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