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From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
	paulus@samba.org, mpe@ellerman.id.au,
	Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH 1/3] powerpc: Add __hard_irqs_disabled()
Date: Tue, 16 May 2017 21:22:02 +1000	[thread overview]
Message-ID: <1494933722.21847.47.camel@kernel.crashing.org> (raw)
In-Reply-To: <1494926782-25700-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com>

On Tue, 2017-05-16 at 14:56 +0530, Aneesh Kumar K.V wrote:
>  
> +static inline bool __hard_irqs_disabled(void)
> +{
> +       unsigned long flags = mfmsr();
> +       return (flags & MSR_EE) == 0;
> +}
> +

Reading the MSR has a cost. Can't we rely on paca->irq_happened being
non-0 ?

(If you are paranoid, add a test of msr as well and warn if there's
a mismatch ...)

Cheers,
Ben.

  parent reply	other threads:[~2017-05-16 11:22 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-16  9:26 [PATCH 1/3] powerpc: Add __hard_irqs_disabled() Aneesh Kumar K.V
2017-05-16  9:26 ` [PATCH 2/3] powerpc/mm: Rename find_linux_pte_or_hugepte Aneesh Kumar K.V
2017-05-16 11:22   ` Benjamin Herrenschmidt
2017-05-17  3:27     ` Aneesh Kumar K.V
2017-05-17  4:57       ` Benjamin Herrenschmidt
2017-05-17  5:30         ` Madhavan Srinivasan
2017-05-29 14:32         ` Aneesh Kumar K.V
2017-05-30  3:21           ` Benjamin Herrenschmidt
2017-05-16  9:26 ` [PATCH 3/3] powerpc/mm: Don't send IPI to all cpus on THP updates Aneesh Kumar K.V
2017-05-16 11:22 ` Benjamin Herrenschmidt [this message]
2017-05-17 11:04 ` [PATCH 1/3] powerpc: Add __hard_irqs_disabled() Balbir Singh

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