From: mark.rutland@arm.com (Mark Rutland)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier
Date: Tue, 10 May 2016 11:34:01 +0100 [thread overview]
Message-ID: <20160510103400.GG687@leverpostej> (raw)
In-Reply-To: <1462875281-5063-1-git-send-email-suzuki.poulose@arm.com>
On Tue, May 10, 2016 at 11:14:41AM +0100, Suzuki K Poulose wrote:
> Remove the unnecessary smp_wmb(), which was added to make sure
> that the update_cpu_boot_status() completes before we mark the
> CPU online. But update_cpu_boot_status() already has dsb() (required
> for the failing CPUs) to ensure the correct behavior.
>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Dennis Chen <dennis.chen@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/kernel/smp.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index b2d5f4e..ec040a8 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -225,8 +225,6 @@ asmlinkage void secondary_start_kernel(void)
> pr_info("CPU%u: Booted secondary processor [%08x]\n",
> cpu, read_cpuid_id());
> update_cpu_boot_status(CPU_BOOT_SUCCESS);
> - /* Make sure the status update is visible before we complete */
> - smp_wmb();
> set_cpu_online(cpu, true);
> complete(&cpu_running);
>
> --
> 1.7.9.5
>
WARNING: multiple messages have this Message-ID (diff)
From: Mark Rutland <mark.rutland@arm.com>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Will Deacon <will.deacon@arm.com>,
Dennis Chen <dennis.chen@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>
Subject: Re: [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier
Date: Tue, 10 May 2016 11:34:01 +0100 [thread overview]
Message-ID: <20160510103400.GG687@leverpostej> (raw)
In-Reply-To: <1462875281-5063-1-git-send-email-suzuki.poulose@arm.com>
On Tue, May 10, 2016 at 11:14:41AM +0100, Suzuki K Poulose wrote:
> Remove the unnecessary smp_wmb(), which was added to make sure
> that the update_cpu_boot_status() completes before we mark the
> CPU online. But update_cpu_boot_status() already has dsb() (required
> for the failing CPUs) to ensure the correct behavior.
>
> Cc: Will Deacon <will.deacon@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Dennis Chen <dennis.chen@arm.com>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Mark.
> ---
> arch/arm64/kernel/smp.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index b2d5f4e..ec040a8 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -225,8 +225,6 @@ asmlinkage void secondary_start_kernel(void)
> pr_info("CPU%u: Booted secondary processor [%08x]\n",
> cpu, read_cpuid_id());
> update_cpu_boot_status(CPU_BOOT_SUCCESS);
> - /* Make sure the status update is visible before we complete */
> - smp_wmb();
> set_cpu_online(cpu, true);
> complete(&cpu_running);
>
> --
> 1.7.9.5
>
next prev parent reply other threads:[~2016-05-10 10:34 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-10 10:14 [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier Suzuki K Poulose
2016-05-10 10:14 ` Suzuki K Poulose
2016-05-10 10:34 ` Mark Rutland [this message]
2016-05-10 10:34 ` Mark Rutland
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