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Date: Wed, 1 Nov 2017 17:30:31 +0100 (CET)
From: Thomas Gleixner <tglx@linutronix.de>
To: Prarit Bhargava <prarit@redhat.com>
cc: linux-kernel@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
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        Mathias Krause <minipli@googlemail.com>,
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Subject: Re: [PATCH 1/3 v4] perf/x86/intel/uncore: Cache logical pkg id in
 uncore driver
In-Reply-To: <20171025120940.15721-2-prarit@redhat.com>
Message-ID: <alpine.DEB.2.20.1711011727080.1942@nanos>
References: <20171025120940.15721-1-prarit@redhat.com> <20171025120940.15721-2-prarit@redhat.com>
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On Wed, 25 Oct 2017, Prarit Bhargava wrote:

> From: Andi Kleen <ak@linux.intel.com>
> 
> The SNB-EP uncore driver is the only user of topology_phys_to_logical_pkg
> in a performance critical path. Change it query the logical pkg ID
> only once at initialization time and then cache it in box structure.

That second sentence needs some care:

  Avoid the lookup in the hotpath and cache the id at initialization
  time. This is also a prerequisite to change the underlying logical
  package management implementation w/o impacting this driver.

Other than that.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>