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Message-Id: <20140326133148.4a347bf956b1c5fd2ae40335@linux-foundation.org>
Date: Wed, 26 Mar 2014 13:31:48 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Artem Fetishev <artem_fetishev@...m.com>
Cc: <eranian@...gle.com>, <linux-kernel@...r.kernel.org>,
Ingo Molnar <mingo@...e.hu>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH] x86: Fix boot on uniprocessor systems
On Tue, 25 Mar 2014 01:59:10 +0300 Artem Fetishev <artem_fetishev@...m.com> wrote:
> On x86 uniprocessor systems topology_physical_package_id() returns -1 which
> causes rapl_cpu_prepare() to leave rapl_pmu variable uninitialized which leads
> to GPF in rapl_pmu_init(). See arch/x86/kernel/cpu/perf_event_intel_rapl.c.
>
> It turns out that physical_package_id and core_id can actually be retreived for
> uniprocessor systems too. Enabling them also fixes rapl_pmu code.
>
> Signed-off-by: Artem Fetishev <artem_fetishev@...m.com>
> ---
> diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
> index d35f24e..1306d11 100644
> --- a/arch/x86/include/asm/topology.h
> +++ b/arch/x86/include/asm/topology.h
> @@ -119,9 +119,10 @@ static inline void setup_node_to_cpumask_map(void) { }
>
> extern const struct cpumask *cpu_coregroup_mask(int cpu);
>
> -#ifdef ENABLE_TOPO_DEFINES
> #define topology_physical_package_id(cpu) (cpu_data(cpu).phys_proc_id)
> #define topology_core_id(cpu) (cpu_data(cpu).cpu_core_id)
> +
> +#ifdef ENABLE_TOPO_DEFINES
> #define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu))
> #define topology_thread_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
> #endif
The patch applies to 3.13 and perhaps earlier kernels. Is it needed in
those kernel versions?
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