* [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier
@ 2016-05-10 10:14 Suzuki K Poulose
2016-05-10 10:34 ` Mark Rutland
0 siblings, 1 reply; 2+ messages in thread
From: Suzuki K Poulose @ 2016-05-10 10:14 UTC (permalink / raw)
To: linux-arm-kernel
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>
---
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
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier
2016-05-10 10:14 [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier Suzuki K Poulose
@ 2016-05-10 10:34 ` Mark Rutland
0 siblings, 0 replies; 2+ messages in thread
From: Mark Rutland @ 2016-05-10 10:34 UTC (permalink / raw)
To: linux-arm-kernel
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
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2016-05-10 10:14 [PATCH] arm64: secondary_start_kernel: Remove unnecessary barrier Suzuki K Poulose
2016-05-10 10:34 ` Mark Rutland
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