Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:6 as permitted sender) client-ip=2620:137:e000::3:6;
Message-ID: <d6cc3829-9b7d-6a0b-c734-c33f6a66959c@intel.com>
Date:   Wed, 13 Sep 2023 13:58:11 -0700
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101
 Firefox/102.0 Thunderbird/102.15.0
Subject: Re: [PATCH 1/5] selftests/resctrl: Extend signal handler coverage to
 unmount on receiving signal
Content-Language: en-US
To:     =?UTF-8?Q?Ilpo_J=c3=a4rvinen?= <ilpo.jarvinen@linux.intel.com>
CC:     Shuah Khan <shuah@kernel.org>,
        Shuah Khan <skhan@linuxfoundation.org>,
        <linux-kselftest@vger.kernel.org>,
        =?UTF-8?Q?Maciej_Wiecz=c3=b3r-Retman?= 
        <maciej.wieczor-retman@intel.com>,
        LKML <linux-kernel@vger.kernel.org>,
        Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>,
        <stable@vger.kernel.org>
References: <20230911111930.16088-1-ilpo.jarvinen@linux.intel.com>
 <20230911111930.16088-2-ilpo.jarvinen@linux.intel.com>
 <4176a620-4cec-5d57-42a3-a15c0fe3eb73@intel.com>
 <aab4b1cc-6eb5-c324-e97e-c6699e2d165@linux.intel.com>
From:   Reinette Chatre <reinette.chatre@intel.com>
In-Reply-To: <aab4b1cc-6eb5-c324-e97e-c6699e2d165@linux.intel.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?dE9uTmtVYjJQVURkcWhsWDNVUzBDMHNTK3p5cGhETDZvODVkd05pVGc1UHhH?=
 =?utf-8?B?UUhibkdZUWtyRDQzTEp4TkxTT1BZdzVvM2Fwc1FON2V4TWxOU2krZXoycS9C?=
 =?utf-8?B?dTNiamJFZWFzYk5aWGpmTC9UTm5lTDNUY3dZUDVqRFlja0V5eHlZckNTMzNJ?=
 =?utf-8?B?M1NaNVVQRHQrNGhNM1RycU5zcUwzMGcyV0FUQnhwVnJaZElQM0Nla1FFY25V?=
 =?utf-8?B?Q2xXQUk3QWE1SDRDMHVDM09icHFFakpvK2hSbDZQOVliQ3BvTnV0TFFWTUNS?=
 =?utf-8?B?QmFoaU5MVHVSZ2FKQ0ZteVlyaklmMy9JYWw2SldCbFZsRTRmYWlTZmxhdTVF?=
 =?utf-8?B?THRmY2RrMHVQVVlFMjVuSjRqbmg4dGZzMVN1V0RsY3MwM0h3RzB1djM2RFgw?=
 =?utf-8?B?WmJzbmtuTW9XMXZUbU9ObjlIY3hZdTJvWHU5SlBPS1RLUjZNUFArcXlCb2gw?=
 =?utf-8?B?R2p4OEtyMkhmd0UyS3hKM1hWa1IxRENmK2xoTkloOExOZUZoaTZ2YThPV2p5?=
 =?utf-8?B?NHR2VllzQjdJZTlMaFdlR2h2QU8yemdLVTNsQVJQNVJsYnNmZUVGMEU3cDFz?=
 =?utf-8?B?Z3J3YWNnNHY0Q0NQb2Y1MUdvTEV1WFA1YzZwdElXbFpDbVJFTWJLajZCemg1?=
 =?utf-8?B?Y1p4QUU2bE1EV29OOC9BSHgwY0tGREZ6MUhpMXNNT1JFb2k4YVF4VENHVmtP?=
 =?utf-8?B?R2ttdW1pNWx0YXEwdVpWWDlqUGEvU0JKalhrTnRsdHZyOXlXOEp4aVZXdnFq?=
 =?utf-8?B?TmJaWDJia0UrV0ErT0o1aExJUzZ5NnJudVZCbVZ0bkNkaHpEZjNvY0VXL1FF?=
 =?utf-8?B?T3ZHQnJBc0VHQVlrMSsrU0dxN3N5RjRILzR0bnMxYTc3RkV6eldiYUIxOTVz?=
 =?utf-8?B?ZkxBUHFhMytnb0JIRytldk00THVKUzRYcjFNZmxZUnI1aGdFdkV5MlN3VkRm?=
 =?utf-8?B?VE1IQXJkTjJucHVnY2ZBYjJ5U1lJSHlMMVZ5WkxJQUpqU0lpVEt2ZFNkeURJ?=
 =?utf-8?B?dVRlTkZlL2tINEFKZk5KVE9GamZnZW8xdC9kOHpkTkVzNCtDRzhEakJUNlY3?=
 =?utf-8?B?TXpPUGZ3c0RWZ0diK1ZyQmUxcC9WSHZWcUhhRDNxS1IzSVlOVVZyalJJOVRp?=
 =?utf-8?B?WVh3L1cwM2pJUExVY0ZubWlsdnFrMWM3VDM0emRRQlZpd25uTVlac2tER2V0?=
 =?utf-8?B?M2NaeVBkV1pPWHdFemNYOE9OZENMcFNraU9ybVZEUk5MQ2FSNXFNNm9XYkx4?=
 =?utf-8?B?WHFHdWNVaVMxUmdMMnJpQTVuZjliOENuL0pseGJlekkyYitDL3BDR1BLZ3Ji?=
 =?utf-8?B?ekVXZG81cW5Jdm9qR2drZTczYjVPNXREQVZKVy9KVk5KejJ4emoxYSt2NzVT?=
 =?utf-8?B?dTQwdWg5enFjcjZOUHpHc0x4bEVwUEx3WnlkTUY5VVdOWjhoeXZHbnNHeTNa?=
 =?utf-8?B?bzBSd2JlRjAzaTJZSEh2aDVVL3UrcncyY090RjJLdC9RaFJXdklQNERqUklo?=
 =?utf-8?B?ZkpDakVqRy9xM0tpVk5VZksvU0xUTFl2UU1NelQySGN1bUVkbUtwRktrVlIy?=
 =?utf-8?B?bXlRVDhIWmwwdU52Zy91Q3FERStEdVBPNlpGS1BxdEJtQ3Q3YStXVFVGSVFG?=
 =?utf-8?B?N05HM0hTWU5TQmVaZ2t6TmpwUllQUjFVMnViM1l3cXNPVmZydndQZTl6Qndx?=
 =?utf-8?B?N0tBcVhrQ0RTMXgxM1h2SkRIM1pxWE1SSEg0OUpFSDVyS2s3MUMxNjhiYnRU?=
 =?utf-8?B?c2hCTWxEcWxsOWFrNUs1MjNpUGJkY01wS0RlVlh2ak9nbDQwMWZ0SnBjNE5x?=
 =?utf-8?B?NWNyeWFTZ3ljdjcvMmlCbTRSaFVnRnFrUHJTNFhWMlBwMzd4V01keHpTSFNM?=
 =?utf-8?B?Rm9FVkx6QU5IVDcyeCszRjJOcWw2WXo5MngrSnlnenc4bWRUQ3JaU2ZabGd5?=
 =?utf-8?B?b3hSdkRRUlg4RGNPS3JaRjJNelhuZlBvTHJiNkhGNmZXdVFNbnJjd29CeUVX?=
 =?utf-8?B?eTE2STJBcWh6aDM0UUljQkk3Ymwrc25IcWlOUmM3S0grUkRFY3FBRkNqc3hL?=
 =?utf-8?B?aU5jY1M4VDY5Z05xUmR3SXdseXk3TU9aaGw3cFE2NnZ5YmJ2bDB4ajdRbXpq?=
 =?utf-8?B?akRHQi9UWCtycWVFTk5KOThwSHBYR2FDemt5eVBvbXJVUVBZbU4vd21HUzFv?=
 =?utf-8?B?NlE9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: 57be3e02-4d61-4daf-ac31-08dbb49c2575
X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7573.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Sep 2023 20:58:14.1969
 (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: NwhzmTKljE0ZbMYA9QM8iVk7XD/Pi3sDKJD0K/SNO+3FibvFBI2F874/pagf5ZRS6KX4rtyORWVZI+n9XAfzAtbNtlC5dMPheTPqJBtZndE=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: BL1PR11MB5350
X-OriginatorOrg: intel.com
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 (pete.vger.email [0.0.0.0]); Wed, 13 Sep 2023 13:58:25 -0700 (PDT)
X-Spam-Status: No, score=-2.3 required=5.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,
	DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS
	autolearn=unavailable autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on pete.vger.email

Hi Ilpo,

On 9/13/2023 3:01 AM, Ilpo Järvinen wrote:
> On Tue, 12 Sep 2023, Reinette Chatre wrote:
>> On 9/11/2023 4:19 AM, Ilpo Järvinen wrote:
>>> Unmounting resctrl FS has been moved into the per test functions in
>>> resctrl_tests.c by commit caddc0fbe495 ("selftests/resctrl: Move
>>> resctrl FS mount/umount to higher level"). In case a signal (SIGINT,
>>> SIGTERM, or SIGHUP) is received, the running selftest is aborted by
>>> ctrlc_handler() which then unmounts resctrl fs before exiting. The
>>> current section between signal_handler_register() and
>>> signal_handler_unregister(), however, does not cover the entire
>>> duration when resctrl FS is mounted.
>>>
>>> Move signal_handler_register() and signal_handler_unregister() call
>>> into the test functions in resctrl_tests.c to properly unmount resctrl
>>> fs. Adjust child process kill() call in ctrlc_handler() to only be
>>> invoked if the child was already forked.
>>
>> Thank you for catching this.
>>
>>>
>>> Fixes: caddc0fbe495 ("selftests/resctrl: Move resctrl FS mount/umount to higher level")
>>> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
>>> Cc: <stable@vger.kernel.org>
>>> ---
>>>  tools/testing/selftests/resctrl/cat_test.c    |  8 -------
>>>  .../testing/selftests/resctrl/resctrl_tests.c | 24 +++++++++++++++++++
>>>  tools/testing/selftests/resctrl/resctrl_val.c | 22 ++++++++---------
>>>  3 files changed, 34 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/selftests/resctrl/cat_test.c
>>> index 97b87285ab2a..224ba8544d8a 100644
>>> --- a/tools/testing/selftests/resctrl/cat_test.c
>>> +++ b/tools/testing/selftests/resctrl/cat_test.c
>>> @@ -167,12 +167,6 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
>>>  		strcpy(param.filename, RESULT_FILE_NAME1);
>>>  		param.num_of_runs = 0;
>>>  		param.cpu_no = sibling_cpu_no;
>>> -	} else {
>>> -		ret = signal_handler_register();
>>> -		if (ret) {
>>> -			kill(bm_pid, SIGKILL);
>>> -			goto out;
>>> -		}
>>>  	}
>>>  
>>>  	remove(param.filename);
>>> @@ -209,10 +203,8 @@ int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
>>>  		}
>>>  		close(pipefd[0]);
>>>  		kill(bm_pid, SIGKILL);
>>> -		signal_handler_unregister();
>>>  	}
>>>  
>>> -out:
>>>  	cat_test_cleanup();
>>>  
>>>  	return ret;
>>> diff --git a/tools/testing/selftests/resctrl/resctrl_tests.c b/tools/testing/selftests/resctrl/resctrl_tests.c
>>> index 823672a20a43..3d66fbdc2df3 100644
>>> --- a/tools/testing/selftests/resctrl/resctrl_tests.c
>>> +++ b/tools/testing/selftests/resctrl/resctrl_tests.c
>>> @@ -73,8 +73,13 @@ static void run_mbm_test(const char * const *benchmark_cmd, int cpu_no)
>>>  
>>>  	ksft_print_msg("Starting MBM BW change ...\n");
>>>  
>>> +	res = signal_handler_register();
>>> +	if (res)
>>> +		return;
>>> +
>>>  	res = mount_resctrlfs();
>>>  	if (res) {
>>> +		signal_handler_unregister();
>>>  		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
>>>  		return;
>>>  	}
>>> @@ -91,6 +96,7 @@ static void run_mbm_test(const char * const *benchmark_cmd, int cpu_no)
>>>  
>>>  umount:
>>>  	umount_resctrlfs();
>>> +	signal_handler_unregister();
>>>  }
>>>  
>>>  static void run_mba_test(const char * const *benchmark_cmd, int cpu_no)
>>> @@ -99,8 +105,13 @@ static void run_mba_test(const char * const *benchmark_cmd, int cpu_no)
>>>  
>>>  	ksft_print_msg("Starting MBA Schemata change ...\n");
>>>  
>>> +	res = signal_handler_register();
>>> +	if (res)
>>> +		return;
>>> +
>>>  	res = mount_resctrlfs();
>>>  	if (res) {
>>> +		signal_handler_unregister();
>>>  		ksft_exit_fail_msg("Failed to mount resctrl FS\n");
>>>  		return;
>>>  	}
>>> @@ -115,6 +126,7 @@ static void run_mba_test(const char * const *benchmark_cmd, int cpu_no)
>>>  
>>>  umount:
>>>  	umount_resctrlfs();
>>> +	signal_handler_unregister();
>>>  }
>>>  
>>
>> This adds more duplicated code for every test. Have you considered a
>> single test setup function that can be used to mount resctrl FS and setup
>> the signal handler paired with a single test teardown function?
> 
> Yes. Consolidating all these is among my not-yet submitted patches.
> I just had to do a backport-friendly Fixes patch first for this.
> 

Could you please help me understand how the duplicate calls are more
backport friendly?

Reinette