From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"<kvm-ppc@vger.kernel.org>" <kvm-ppc@vger.kernel.org>,
"<kvm@vger.kernel.org> list" <kvm@vger.kernel.org>
Subject: Re: [PATCH 2/3] kvm/ppc: IRQ disabling cleanup
Date: Wed, 10 Jul 2013 23:08:37 +0000 [thread overview]
Message-ID: <1373497717.8183.237@snotra> (raw)
In-Reply-To: <328E7C2E-1D19-41D5-95F4-B0AFCA320208@suse.de> (from agraf@suse.de on Wed Jul 10 18:04:53 2013)
On 07/10/2013 06:04:53 PM, Alexander Graf wrote:
>
> On 11.07.2013, at 01:01, Benjamin Herrenschmidt wrote:
>
> > On Thu, 2013-07-11 at 00:57 +0200, Alexander Graf wrote:
> >>> #ifdef CONFIG_PPC64
> >>> + /*
> >>> + * To avoid races, the caller must have gone directly from
> having
> >>> + * interrupts fully-enabled to hard-disabled.
> >>> + */
> >>> + WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS);
> >>
> >> WARN_ON(lazy_irq_pending()); ?
> >
> > Different semantics. What you propose will not catch irq_happened
> = 0 :-)
>
> Right, but we only ever reach here after hard_irq_disable() I think.
And the WARN_ON helps us ensure that it stays that way.
-Scott
WARNING: multiple messages have this Message-ID (diff)
From: Scott Wood <scottwood@freescale.com>
To: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
"<kvm-ppc@vger.kernel.org>" <kvm-ppc@vger.kernel.org>,
"<kvm@vger.kernel.org> list" <kvm@vger.kernel.org>
Subject: Re: [PATCH 2/3] kvm/ppc: IRQ disabling cleanup
Date: Wed, 10 Jul 2013 18:08:37 -0500 [thread overview]
Message-ID: <1373497717.8183.237@snotra> (raw)
In-Reply-To: <328E7C2E-1D19-41D5-95F4-B0AFCA320208@suse.de> (from agraf@suse.de on Wed Jul 10 18:04:53 2013)
On 07/10/2013 06:04:53 PM, Alexander Graf wrote:
>
> On 11.07.2013, at 01:01, Benjamin Herrenschmidt wrote:
>
> > On Thu, 2013-07-11 at 00:57 +0200, Alexander Graf wrote:
> >>> #ifdef CONFIG_PPC64
> >>> + /*
> >>> + * To avoid races, the caller must have gone directly from
> having
> >>> + * interrupts fully-enabled to hard-disabled.
> >>> + */
> >>> + WARN_ON(local_paca->irq_happened != PACA_IRQ_HARD_DIS);
> >>
> >> WARN_ON(lazy_irq_pending()); ?
> >
> > Different semantics. What you propose will not catch irq_happened
> == 0 :-)
>
> Right, but we only ever reach here after hard_irq_disable() I think.
And the WARN_ON helps us ensure that it stays that way.
-Scott
next prev parent reply other threads:[~2013-07-10 23:08 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-10 22:47 [PATCH 0/3] kvm/ppc: fixes/cleanup Scott Wood
2013-07-10 22:47 ` Scott Wood
2013-07-10 22:47 ` [PATCH 1/3] kvm/ppc: Call trace_hardirqs_on before entry Scott Wood
2013-07-10 22:47 ` Scott Wood
2013-07-10 22:47 ` [PATCH 2/3] kvm/ppc: IRQ disabling cleanup Scott Wood
2013-07-10 22:47 ` Scott Wood
2013-07-10 22:57 ` Alexander Graf
2013-07-10 22:57 ` Alexander Graf
2013-07-10 23:01 ` Benjamin Herrenschmidt
2013-07-10 23:01 ` Benjamin Herrenschmidt
2013-07-10 23:04 ` Alexander Graf
2013-07-10 23:04 ` Alexander Graf
2013-07-10 23:08 ` Scott Wood [this message]
2013-07-10 23:08 ` Scott Wood
2013-07-10 23:09 ` Alexander Graf
2013-07-10 23:09 ` Alexander Graf
2013-09-05 22:09 ` Scott Wood
2013-09-05 22:09 ` Scott Wood
2013-09-05 23:06 ` Alexander Graf
2013-09-05 23:06 ` Alexander Graf
2013-10-04 17:22 ` Scott Wood
2013-10-04 17:22 ` Scott Wood
2013-12-29 15:43 ` Alexander Graf
2013-12-29 15:43 ` Alexander Graf
2014-01-03 2:51 ` Scott Wood
2014-01-03 2:51 ` Scott Wood
2014-01-09 12:38 ` Alexander Graf
2014-01-09 12:38 ` Alexander Graf
2013-07-10 22:47 ` [PATCH 3/3] kvm/ppc/booke: Don't call kvm_guest_enter twice Scott Wood
2013-07-10 22:47 ` Scott Wood
2013-07-10 22:59 ` [PATCH 0/3] kvm/ppc: fixes/cleanup Alexander Graf
2013-07-10 22:59 ` Alexander Graf
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