From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "tiejun.chen" <tiejun.chen@windriver.com>
Cc: Scott Wood <scottwood@freescale.com>,
Mihai Caraman <mihai.caraman@freescale.com>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: Re: [PATCH] powerpc: Make hard_irq_disable() do the right thing vs. irq tracing
Date: Tue, 07 May 2013 07:25:20 +0000 [thread overview]
Message-ID: <1367911520.5769.12.camel@pasglop> (raw)
In-Reply-To: <5188AA2D.1040802@windriver.com>
On Tue, 2013-05-07 at 15:15 +0800, tiejun.chen wrote:
> Could we simplify this as follows:
>
> +#define hard_irq_disable() do { \
> + __hard_irq_disable(); \
> + if (get_paca()->soft_enabled) { \
> + trace_hardirqs_off(); \
> + get_paca()->soft_enabled = 0; \
> + } \
> + get_paca()->irq_happened |= PACA_IRQ_HARD_DIS; \
> +} while(0)
I'd rather not. When lockdep is not enabled trace_hardirqs_off() is a
nop and thus we have no conditional at all which is arguably better...
Cheers,
Ben.
WARNING: multiple messages have this Message-ID (diff)
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "tiejun.chen" <tiejun.chen@windriver.com>
Cc: Scott Wood <scottwood@freescale.com>,
Mihai Caraman <mihai.caraman@freescale.com>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Subject: Re: [PATCH] powerpc: Make hard_irq_disable() do the right thing vs. irq tracing
Date: Tue, 07 May 2013 17:25:20 +1000 [thread overview]
Message-ID: <1367911520.5769.12.camel@pasglop> (raw)
In-Reply-To: <5188AA2D.1040802@windriver.com>
On Tue, 2013-05-07 at 15:15 +0800, tiejun.chen wrote:
> Could we simplify this as follows:
>
> +#define hard_irq_disable() do { \
> + __hard_irq_disable(); \
> + if (get_paca()->soft_enabled) { \
> + trace_hardirqs_off(); \
> + get_paca()->soft_enabled = 0; \
> + } \
> + get_paca()->irq_happened |= PACA_IRQ_HARD_DIS; \
> +} while(0)
I'd rather not. When lockdep is not enabled trace_hardirqs_off() is a
nop and thus we have no conditional at all which is arguably better...
Cheers,
Ben.
next prev parent reply other threads:[~2013-05-07 7:25 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-07 7:04 [PATCH] powerpc: Make hard_irq_disable() do the right thing vs. irq tracing Benjamin Herrenschmidt
2013-05-07 7:04 ` Benjamin Herrenschmidt
2013-05-07 7:15 ` tiejun.chen
2013-05-07 7:15 ` tiejun.chen
2013-05-07 7:25 ` Benjamin Herrenschmidt [this message]
2013-05-07 7:25 ` Benjamin Herrenschmidt
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