From:   "Bae, Chang Seok" <chang.seok.bae@intel.com>
To:     Thomas Gleixner <tglx@linutronix.de>
CC:     "Sang, Oliver" <oliver.sang@intel.com>,
        Borislav Petkov <bp@suse.de>,
        LKML <linux-kernel@vger.kernel.org>,
        "lkp@lists.01.org" <lkp@lists.01.org>, lkp <lkp@intel.com>,
        "Huang, Ying" <ying.huang@intel.com>,
        "Tang, Feng" <feng.tang@intel.com>,
        "zhengjun.xing@linux.intel.com" <zhengjun.xing@linux.intel.com>,
        "Yin, Fengwei" <fengwei.yin@intel.com>
Subject: Re: [x86/signal]  3aac3ebea0:  will-it-scale.per_thread_ops -11.9%
 regression
Thread-Topic: [x86/signal]  3aac3ebea0:  will-it-scale.per_thread_ops -11.9%
 regression
Thread-Index: AQHX6wjSQCOD0XfrOkWXZZ4ZMWo0/6wnCWQAgABXAQA=
Date:   Tue, 7 Dec 2021 18:49:59 +0000
Message-ID: <81783AEA-1313-4353-837D-8217DEF3B9A2@intel.com>
References: <20211207012128.GA16074@xsang-OptiPlex-9020> <87bl1s357p.ffs@tglx>
In-Reply-To: <87bl1s357p.ffs@tglx>
Accept-Language: en-US
Content-Language: en-US
x-ms-exchange-antispam-messagedata-chunkcount: 1
x-ms-exchange-antispam-messagedata-0: =?us-ascii?Q?ozHA9vfrzLgEbw97stfyFihvke64IMsCtCS6qEWm6Lkfdxu4sk5xzuDThBSk?=
 =?us-ascii?Q?XojKVfkAQyubIA2GLIKzVj7ySFEnrxAI5lScGMjwoQ7fL7IKu/wJ7Tvk4SMj?=
 =?us-ascii?Q?idk8eFAJ9R/rwFQ/pon/c/mjW6VEGRX5mrsptG3SXyHSiyxVk7gklcU4uaiN?=
 =?us-ascii?Q?LQlK/88C2nFBOySLuuXxAER1W0Hb/O9Fi9DFkMtJcE0wCQFykBIbgr1oYuUz?=
 =?us-ascii?Q?Y089xks+n3cex2d02egwGfGemSQUZbVHAi4FDWUWand78GEGUQeK/n4OB81P?=
 =?us-ascii?Q?x6729D8U46jR10SUohbMoSxKfnAqUQDdBQXZA1w3HfyAMUCwKTU0LvSPlAJ+?=
 =?us-ascii?Q?nlr5fo4ptS4FAKWFt7l2IJFC7h0ToZftKw1cBmsZLeHxJMpCkAro9gIhT6SF?=
 =?us-ascii?Q?HDTEluzjurEDAPa/iSh1Y+Dz2Vk961fKNbUYXg9FmlelyoZYkOOh+QZPxb38?=
 =?us-ascii?Q?WnQiGSj3NjwyGR24gWFXFIII3QHOAoBPoUolgUDWyP5zLCzRm5G/GtlhGHdc?=
 =?us-ascii?Q?S4H+Kc30B7lVB/UuTDA3iqyR49Y5A3fHQVI49mvT7UWMaf2leSkVEaddiB4O?=
 =?us-ascii?Q?NwOjUIxdxLBEua861hwONHrj33h/E/xT+dfiffGHKZUwgw0PftmnmOeMoDaX?=
 =?us-ascii?Q?SctZLm6SYR3bzIvY/saZqMfSI2fARJWgFZjE3U4dklknVgZaua60Ll+YXDG1?=
 =?us-ascii?Q?HOga+EZo7n4++bBq08Cc+NUqCYpqgSsrz3BOAgK+BDt8gZEMuSub9sPYgsxS?=
 =?us-ascii?Q?7v7mKj2KVqTVAA9Mb80jHLrh7m4rjaGYytxVz8+4jA0gSLc4OBo9d3tio+5t?=
 =?us-ascii?Q?vUr5OoF0v3o32TkGgb4QSSfxxQ14s8ElyRvct2oU78Te0LA8hHR4mq7W1qmx?=
 =?us-ascii?Q?Bhnm3cOkmQEDZBqS+lQphRk0qBO6A9qz+l2PgovfaHVIuTBr+QNcLiYIgwKL?=
 =?us-ascii?Q?nSfOtY1hImlEL6hyVbL3kZXng1g3ujbSyx/gfGxnMtYfP9cUMddbAubgKHzG?=
 =?us-ascii?Q?5ZinzmwJ1I8sGBFQL35fGQmiQ33g2vyow/9yQcly4BbPDQQhiTeHAKMFgg65?=
 =?us-ascii?Q?2FrwDhzj4pQtmSo5Mp2oZolLhZ8AADXnAztX0doJJfPA6JUvTdiu/WU+/RIb?=
 =?us-ascii?Q?TsqOG1H4tf9tpZQyLxORqmNjOh1Rl7PvqnfaC7p1RGqNKORBEa2XEVG6P86i?=
 =?us-ascii?Q?DCKEl45Ckt/inuWuCYLVyF0uIVwMvBuv8c6vo9MEt8feaDAntnyy0DTzl7da?=
 =?us-ascii?Q?PY/GUIHNWdN1K55fsKxzDsDSltKWPUzG8UsBO+JF/eEqcfgcQPoMcMrJ+BDT?=
 =?us-ascii?Q?mmBBvIpamCJm115CYbVN4Ac7jA4BpGZd9mkyHFmPoTM+gTr9bvOimuslwFLq?=
 =?us-ascii?Q?MkPaqVcTPBHQSHrWimGHsxMJystIxg/892aCthvpKclcuCkneZrOJT4WTPXG?=
 =?us-ascii?Q?R04FtNdgP/mWPe/QwALpj6JgsgIO1VPPk8IvgLC3GYsEKQFWdJT1j6wOtIZ3?=
 =?us-ascii?Q?VlF33M05gSd5C2coAsWMMrhg6NYl5mVzdxH/2LMVwdbN2qG+yMLs+AUUZpSb?=
 =?us-ascii?Q?js/FmtZjB2BU5sfXmzr1Hb+Vr/rkZL0+9+IwiwgXLxXASckBWzliBnZOsz3m?=
 =?us-ascii?Q?f4VlUhU4H4/4XVDYEZTAcQufUBegdWeJVzqtncDx/okJ62S/Tdhnw7sJytkh?=
 =?us-ascii?Q?A9eyx0BZyTrKC/BPvkmH6Lh3qic=3D?=
Content-Type: text/plain; charset="us-ascii"
Content-ID: <69AE2623D6EB09478537C18C89C87979@namprd11.prod.outlook.com>
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-AuthSource: CO1PR11MB4849.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-Network-Message-Id: ccc1257c-af7e-48f0-3c12-08d9b9b25eb3
X-MS-Exchange-CrossTenant-originalarrivaltime: 07 Dec 2021 18:49:59.3180
 (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: BY2Vu625XCGiTjLUq9Nh2QLMENy3JcAvD7piMnvhsLS2OXn4aucHk1PZbt3kmaFqRqJK6t6P1ZKK/fp4DvWuMKbEVxh60EelMb8TXpRdXgY=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR11MB1440
X-OriginatorOrg: intel.com
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Dec 7, 2021, at 05:38, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Tue, Dec 07 2021 at 09:21, kernel test robot wrote:
>> (please be noted we made some further analysis before reporting out,
>> and thought it's likely the regression is related with the extra spinloc=
k
>> introducded by enalbling DYNAMIC_SIGFRAME. below is the full report.)
>>=20
>> FYI, we noticed a -11.9% regression of will-it-scale.per_thread_ops due =
to commit:
>=20
> Does that use sigaltstack() ?

FWIW, I was also wondering about this with:

$ git clone https://github.com/antonblanchard/will-it-scale.git
$ cd will-it-scale/
$ git grep sigaltstack
$

But, the test seems to use python via runtest.py. And the python code has
sigaltstack():
    https://github.com/python/cpython/blob/main/Modules/faulthandler.c#L454

Thanks,
Chang=