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From:   Peter Newman <peternewman@google.com>
Date:   Thu, 8 Dec 2022 10:45:24 +0100
Message-ID: <CALPaoCj7JanopjrvZEOvpnNWv_-e2qgre+OLxS5A=3q3hkn0pw@mail.gmail.com>
Subject: Re: [PATCH] x86/resctrl: Fix event counts regression in reused RMIDs
To:     "Yu, Fenghua" <fenghua.yu@intel.com>
Cc:     "Chatre, Reinette" <reinette.chatre@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "H. Peter Anvin" <hpa@zytor.com>,
        James Morse <james.morse@arm.com>,
        Shaopeng Tan <tan.shaopeng@fujitsu.com>,
        Jamie Iles <quic_jiles@quicinc.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "Eranian, Stephane" <eranian@google.com>
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Hi Fenghua,

On Wed, Dec 7, 2022 at 8:26 PM Yu, Fenghua <fenghua.yu@intel.com> wrote:
> > Fixes: 1d81d15db39c ("x86/resctrl: Move mbm_overflow_count() into
> > resctrl_arch_rmid_read()")
>
> Are you sure the patch fixes 1d81d15db39c? This commit is just a refactoring patch and doesn't change resctrl_arch_reset_rmid().

Yes, the breaking change was actually in __mon_event_count(). That
patch removes the initialization of mbm_state::prev_msr and switches
to using arch_mbm_state::prev_msr.

-Peter