Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8;
From:   "Luck, Tony" <tony.luck@intel.com>
To:     "Tang, Feng" <feng.tang@intel.com>
CC:     "Sang, Oliver" <oliver.sang@intel.com>,
        "oe-lkp@lists.linux.dev" <oe-lkp@lists.linux.dev>,
        lkp <lkp@intel.com>,
        "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>,
        "Huang, Ying" <ying.huang@intel.com>,
        "Yin, Fengwei" <fengwei.yin@intel.com>,
        Borislav Petkov <bp@alien8.de>,
        "Yazen Ghannam" <yazen.ghannam@amd.com>,
        "Smita.KoralahalliChannabasappa@amd.com" 
        <Smita.KoralahalliChannabasappa@amd.com>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "patches@lists.linux.dev" <patches@lists.linux.dev>
Subject: RE: [PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation
Thread-Topic: [PATCH v9 2/3] x86/mce: Add per-bank CMCI storm mitigation
Thread-Index: AQHZ9vG7TU6w8G+TdkO4n2sYy/mmYrBEV9iAgABlLACAAAgpAIAAGdzg
Date:   Wed, 11 Oct 2023 17:23:54 +0000
Message-ID: <SJ1PR11MB6083154D148B42B8B7BC48D9FCCCA@SJ1PR11MB6083.namprd11.prod.outlook.com>
References: <20231004183623.17067-3-tony.luck@intel.com>
 <202310111637.dee70328-oliver.sang@intel.com>
 <SJ1PR11MB6083D191286779302821A7EAFCCCA@SJ1PR11MB6083.namprd11.prod.outlook.com>
 <ZSbCYt35j20ezT98@feng-clx>
In-Reply-To: <ZSbCYt35j20ezT98@feng-clx>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?LQIJFhg09hzjhEuKn5ICUEalsaoeolw76StKPCMRqk/cs8XbvRpsqrrbkfQh?=
 =?us-ascii?Q?zPp0Tq6wKz+GRICmW9O/E65e6bGayCrfTdckeOmQcydOhc/bR1EiQ8UNPtNE?=
 =?us-ascii?Q?TuCWLzHkUEKvtmnIbn65tw+AVkujZkV8PDsUtnJYXrQ6K6xuzgTLCkH23TmH?=
 =?us-ascii?Q?0xN9fSNfuPwBh2ia0lnjVvWcDwuKcnZJZJhlE3V+sNWuZTElj+e/1Uuqk37O?=
 =?us-ascii?Q?2h+h5Iz4Ay5AnpzKM4eeJQpO45JvT8FmFUM9K0kHOYKVKfnMqCeMJfDRRbks?=
 =?us-ascii?Q?02HQ7LpkSXpzgHdv4VdplVzKa8KN6E64gToerlNMQAFvcyKtWGGCF6E0LFtK?=
 =?us-ascii?Q?KbhF0gcGzF22JW38W0lJO4no/96SL3cMyTM6r/YkJX2GtwQCMrE/H/MlX2S8?=
 =?us-ascii?Q?CXs80pYzoGt1xXFQss7XmIUe13TmQ4YsZ5vc4K0319IqE/I9mamXr76MAeEy?=
 =?us-ascii?Q?vHGgxqepU7G1pA1bs39D7njltpY/Pm/WaH4ETI3OZQENGqz1hi7V9bGF5Q9L?=
 =?us-ascii?Q?stnNTXaE27RFairnnKd6SFnWIN4tVy8FgmcrV7clbAad4cCuDIY1I9YNyROx?=
 =?us-ascii?Q?8IuJHqRD/IR283kNqEOKbJYYc/25eXEN0GPFXmkGvK/ySNRhTQWX9M6Az+5m?=
 =?us-ascii?Q?fupn5Ss0WF52uom+CY1V/VH8Wf22SFYxnLzAaFWMFIbv4y/473l10fjFeEkM?=
 =?us-ascii?Q?MsTwC4BiW6FQD6DBMr/U+Sn0YH99d1H6iaI3r3TVo1s0CFkqc7LJu5PtfFx/?=
 =?us-ascii?Q?/BLwOFTULCzHu+4L+pPsTJQMDmA6BMFHXYThbX976VT76XjxW8s9DjLauZSc?=
 =?us-ascii?Q?3yKlsaGZcXyRyxPuP0CFvrYD/KLPIL0DBRf9jtcBweUiVjepQfcaDcF13+bc?=
 =?us-ascii?Q?G/7Edg5WdeRsR0wLDq3zLDlwpuOnBzAvPBAogO28qI7CtV9pWTs3qptW+65h?=
 =?us-ascii?Q?kasDPX/lI6Yr11w1LP9HCDcwMAYk858QpzvR24Lcncpf4hpwlyqiTjI+pkS9?=
 =?us-ascii?Q?AHVj9n91MH/Ln2k1s11SJnpR4eUhMter4ADgXcBvVoXvKKWbXHAWkpPAK7O6?=
 =?us-ascii?Q?2E+rhKXGSbUsZ9ThMbY3n1Wb8GHeW8uwgZS4vdy1THg6pBT/TkES4nHPH7cG?=
 =?us-ascii?Q?PvNsrQMhekVwtFyYLHOvJHJso2v66J54jXrQ9a+53TyIFBsV9gQn+4jbMJtH?=
 =?us-ascii?Q?DXapsD7Gyu2w8C3dm0xaMUXjSkyKPQiSTmgv3nGkJqy/vBvsDOopW4g4l7r4?=
 =?us-ascii?Q?59AYfBwFkRRxA7rvHOyIRgJosTuID3ly+C03b1V3VeGxw/tL9MC+FOYr/Ocs?=
 =?us-ascii?Q?cPAk/jt658TWNT0MySC63hcMF/nAX+zsYUaqImr63CrcoDIVeet4JcRxiBj3?=
 =?us-ascii?Q?viKt5wNQBm8JgsGL1MTg/MYuQ00M4rSCfMmaJ+Kce/S/k8RmfPb4NC/x7oQP?=
 =?us-ascii?Q?1q71V2kY7YmkEuRdO5yE3W+VLQUiWGSC98PTa5sszrNetGAUlA2nLfqJtMv1?=
 =?us-ascii?Q?Q8pd5oUWs5wxoUZNjLgFT2tBTDOlnSCyw8lLFBGBsdJJ8Ow4brLIMYS9d8T2?=
 =?us-ascii?Q?eP2x72Iu7m51BoXByAxF+ctwE2RJBK3EotDxdwL3?=
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: SJ1PR11MB6083.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 17ade6f6-ed46-4e7b-579c-08dbca7ed830
X-MS-Exchange-CrossTenant-originalarrivaltime: 11 Oct 2023 17:23:54.4728
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 46c98d88-e344-4ed4-8496-4ed7712e255d
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: W4x9t9I3oju3GxLWtc3hM3ZLnsDi4yVBnNk3f6ZWTcfL2OmeOno7SM49gXy+y2ZqnSGXJ5z6J9CF18hZ7mS/9w==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR11MB6199
X-OriginatorOrg: intel.com
X-Spam-Status: No, score=2.7 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,RCVD_IN_SBL_CSS,SPF_HELO_NONE,SPF_PASS,
	URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on fry.vger.email
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (fry.vger.email [0.0.0.0]); Wed, 11 Oct 2023 10:24:18 -0700 (PDT)
X-Spam-Level: **

> IIRC, CONFIG_DEBUG_FORCE_FUNCTION_ALIGN_64B was enabled in 0Day's
> kernel config for quite a while, to force each funtion's start
> address aligned on 64 bytes. Don't know if this has been changed
> recently.
>
> Also I noticed the patch introduce a new per-cpu variable 'storm_desc",
> if the function address is 64B aligned, then per-cpu data alignment
> may be related.

If adding (removing, changing) per-cpu variables can cause 8% performance
changes, then maybe there needs to be some way to insulate the builds
from these side effects (as was done with the 64-byte function alignment).
I've no ideas on how to achieve that :-(

"storm_desc" is a largish per-cpu variable at 1568 bytes. But that doesn't
quite get it into the top 20.

In the config used for my kernel build, it does appear just before a bunch
of interrupt related per-cpu variables. Those might be sensitive to alignme=
nt?

000000000001ff40 d smca_misc_banks_map
000000000001ff48 d bank_map
000000000001ff50 d threshold_banks
000000000001ff60 d storm_desc
0000000000020580 d tsc_adjust
00000000000205c0 d lapic_events
00000000000206c0 d vector_cleanup
0000000000020720 D __uv_cpu_info
0000000000020738 d ipi_mask

-Tony