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Subject: Re: [PATCH 0/2] x86/intel_rdt and perf/x86: Fix lack of coordination
 with perf
From:   Reinette Chatre <reinette.chatre@intel.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Dave Hansen <dave.hansen@intel.com>, tglx@linutronix.de,
        mingo@redhat.com, fenghua.yu@intel.com, tony.luck@intel.com,
        vikas.shivappa@linux.intel.com, gavin.hindman@intel.com,
        jithu.joseph@intel.com, hpa@zytor.com, x86@kernel.org,
        linux-kernel@vger.kernel.org
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Message-ID: <05008c82-7bef-e02d-0274-f4608e86b41d@intel.com>
Date:   Fri, 10 Aug 2018 10:52:21 -0700
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Just one clarification ...

On 8/10/2018 9:25 AM, Reinette Chatre wrote:
> static inline int x86_perf_event_error_state(struct perf_event *event)
> {
>         int ret = 0;
>         u64 tmp;
> 
>         ret = perf_event_read_local(event, &tmp, NULL, NULL);
>         if (ret < 0)
>                 return ret;
> 
>         if (event->attr.pinned && event->oncpu != smp_processor_id())
>                 return -EBUSY;

I am preparing a patch series and in that the above extra test will be
included as the last sanity check in perf_event_read_local() as you
suggested. This inline function will thus go away and the only error
state check would be a call to perf_event_read_local().

Reinette