Received-SPF: pass (google.com: domain of linux-kernel+bounces-173798-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <2f172ee0-1c9a-4637-b2fd-574acb9a69a7@intel.com>
Date: Wed, 8 May 2024 13:24:50 -0700
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v3] selftests/resctrl: fix clang build warnings related to
 abs(), labs() calls
To: John Hubbard <jhubbard@nvidia.com>, Shuah Khan <shuah@kernel.org>
CC: Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers
	<ndesaulniers@google.com>, Bill Wendling <morbo@google.com>, Justin Stitt
	<justinstitt@google.com>, Fenghua Yu <fenghua.yu@intel.com>, Valentin Obst
	<kernel@valentinobst.de>, <linux-kselftest@vger.kernel.org>, LKML
	<linux-kernel@vger.kernel.org>, <llvm@lists.linux.dev>,
	=?UTF-8?Q?Ilpo_J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
References: <20240508194132.269168-1-jhubbard@nvidia.com>
Content-Language: en-US
From: Reinette Chatre <reinette.chatre@intel.com>
In-Reply-To: <20240508194132.269168-1-jhubbard@nvidia.com>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8bit
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?Ym1WbzVwUm9BclNiaUM3TDlIbXdMcHRqMUpjTGtYWHIxSmVrT1p0ZElVNWhI?=
 =?utf-8?B?MVk1cHJES3BwSU1Ybk9hcCs3YlhLcWlVM3ZUNTN2bTJKTzdnM0lnWUxDQ0Vm?=
 =?utf-8?B?YkFmZmJYYjl2S0c4bmQvQ1pPWXNBVEVjWCswZXhGK1UvVzc4akdOYlQrRzRE?=
 =?utf-8?B?WDdqZFdBSXdJd2NlRWVhSnJ6aFNvbi9wKzhaamRST1Z1MnZCeHY0N1BjMzk5?=
 =?utf-8?B?TWpQam15UmY3czcyRTE2LyswNDVrZVZ2d3pPaDZLb2VXdEJ6WUtQU0ppcWVU?=
 =?utf-8?B?aWhuVGRvaTA2YllkZGZKVVpLWVpwSDloNklob0JlUjlXbEE1U2dKb29vUzR0?=
 =?utf-8?B?dC9BUERsQ2hEbnMxNTRzYm9tV1RaeGE0U21MN3AyRi9RRGRIaVk2VSs3ZTY0?=
 =?utf-8?B?NXFieis0bmppMmxLdXRZeHQyRzFCSEpmMWhDWGZzb0dpcjVzaUdYbWVZR2pF?=
 =?utf-8?B?THcwVkwyY2hOaEhNQmhGTXlSZ29QTEpiT3NYYkRaRDBBZHlibzBWdTliMWxj?=
 =?utf-8?B?V09kRno5aDdlY3RWd0l5djhYcGZpbmdrOFVTUGVoUDJKK05PUUJVM2JOclRJ?=
 =?utf-8?B?QWpPeURUMkFwQmllWXFORjJIVllQUWF6VFdWSzNhVzUrZHNXK1Q2WGQxUERZ?=
 =?utf-8?B?emc2MFNrbnd0UlFSemJ2ZVhWVjJMNGd6WitjY1pkUVJYTEMxVFB3WTlzMmRO?=
 =?utf-8?B?TjFlcEkxQUdxNVErdEcxK0lyTm82ZmRuYnJJVDFudWdwbEZnYm9IK3BIVWps?=
 =?utf-8?B?cHhVdnp5K3NTR3Ixd3VtRUZBU3RoWkgvZ2xzWkt1U3NJUlFmQlZod05heG9j?=
 =?utf-8?B?aGtnV3MxWGgvRWI3WjlSbTRrbVJiZlcxYm5zbUVOb3pzckZEY1ZDbVJZcWo4?=
 =?utf-8?B?eFdCNVp5Y3BmLzgwVlNyQnprR3BMQWFqUXRHQUM1aHF3RFlyZkhEdlhweDNB?=
 =?utf-8?B?ZmtwdTNBUmdKYkNDTlJScWZoRTNOQTZOL0ZhT0piNUdJeUVvZXg1elBsQlNo?=
 =?utf-8?B?RXk5Qzl0SFlYOXA4ZTIyb0tFd2taa25hSnJQTlp1WDFJYjZtckIrVSt4ZGpY?=
 =?utf-8?B?bGVxalkyWDVCK3RjYWJNZVd2Y0x3SEg0d0U3c3ZTdlpFRmZqUmg2dHV2R25W?=
 =?utf-8?B?YlNCQTQxazB1dmYzUFJWZkdOd0VESUIrL2FncDE1QXA3R1FDc3haSFFZZ3dv?=
 =?utf-8?B?VU9qL3RORmlZUFZ0cHpBYmFaM2cwY3ExWnBEa1doRW1WKzliMkQ2NVhpS29v?=
 =?utf-8?B?Q2pDaXdCNlNldzZvRS9Pc25CTWVhc2VvNkpmRGhkdC81SGowcm5OUkhMNDhO?=
 =?utf-8?B?QXlDYjdCbWlSUmZyMlh1TElwNFoyNk5BNFRhUEluL3VHVGRtL2NlZEI1ZVdr?=
 =?utf-8?B?dDVDRFpkTCtBZUpYS2Q1RUJGMDVCMFBTbFRtV1VCdU5MTjliM1ljSFY1TWF5?=
 =?utf-8?B?cmxOME1XVkh2Rkh4eU5HUGIwWFhHZWs4Mk5XbGpVbzhESzNWRmMxaUlUV2U2?=
 =?utf-8?B?TVBianRWUFFJRS9xYWxYbEpaaEhyRHMrL24zdlZYeVdBY0poZEMxOTdSeEl4?=
 =?utf-8?B?Z25XMU94NytjVXBBYWIrdkhnZjJNS09MbldpcTBZUkZJamV1TysxdmM2NGhZ?=
 =?utf-8?B?Zno1NlBoWXVMZVdLWEhCVnhtcVM4Vk1ZWU5qeWNsaERlSGVtUjdnWEI3ajJS?=
 =?utf-8?B?WUxpSU9XTDNrOHowN29ZUnVXY1RiWm0xYmU2ZFluQnlUdHhWMUhjVVlDVlF0?=
 =?utf-8?B?cUtaMFpncHRXZ1hpNGF3TS8wdTNBRzVTb2hLU0FON1d5TjZZeGFWcFhCUmlx?=
 =?utf-8?B?c242Um5YRzhiOGhnT3p1VTk3YXNQcHZac2pJdk8wYzFRQTdQa2xZWDI4a3ZQ?=
 =?utf-8?B?NkU4cmlPSmF5TDlqNjRTdWR2RnEwbnNZS1dDZzRrNDl0c0Z0cmhJZkVZaGV5?=
 =?utf-8?B?VFZHd1FsemdHd0tBdU9PMFROemJxV3NqLzNQYWNyWXJPMGd2TElud2p6Wlgv?=
 =?utf-8?B?SUhSVDRFbmdmMjNwVHVhNzNzcmxwVzRROW1VYVBuRUxwR3g2QVJWRk9WTnQx?=
 =?utf-8?B?NGNsb203UjdQOExtMDh2VllQM0hKRUpwTWN5YjNGdjhnejR4TGp1RkxKU3JS?=
 =?utf-8?B?dlM3R3crMm1vNjNURWpxNFpMS1NORitpbWU2SExoM1NpUVNramdnOEVJUlVl?=
 =?utf-8?B?eXc9PQ==?=
X-MS-Exchange-CrossTenant-Network-Message-Id: b68cbe48-5846-415a-0f6f-08dc6f9ceaef
X-MS-Exchange-CrossTenant-AuthSource: SJ2PR11MB7573.namprd11.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 08 May 2024 20:24:52.8522
 (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: r5lHPX8FCrzGce1cOrpOj5ELrzZfYFEohbLUllioOHahfUcbItVKQNCqETJ1UipqiZ29p/uAVmDhcUHymHVokA1xb3S9YynJZtyvUpslR1w=
X-MS-Exchange-Transport-CrossTenantHeadersStamped: SJ0PR11MB5816
X-OriginatorOrg: intel.com

Hi John,

On 5/8/2024 12:41 PM, John Hubbard wrote:
> When building with clang, via:
> 
>     make LLVM=1 -C tools/testing/selftests
> 
> ...two types of warnings occur:
> 
>     warning: absolute value function 'abs' given an argument of type
>     'long' but has parameter of type 'int' which may cause truncation of
>     value
> 
>     warning: taking the absolute value of unsigned type 'unsigned long'
>     has no effect
> 
> Fix these by:
> 
> a) using labs() in place of abs(), when long integers are involved, and
> 
> b) Change to use signed integer data types, in places where subtraction
>    is used (and could end up with negative values).
> 
> c) Remove a duplicate abs() call in cmt_test.c.
> 
> Cc: Reinette Chatre <reinette.chatre@intel.com>
> Cc: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>
> ---
>  tools/testing/selftests/resctrl/cmt_test.c | 4 ++--
>  tools/testing/selftests/resctrl/mba_test.c | 2 +-
>  tools/testing/selftests/resctrl/mbm_test.c | 2 +-
>  3 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/testing/selftests/resctrl/cmt_test.c b/tools/testing/selftests/resctrl/cmt_test.c
> index a81f91222a89..05a241519ae8 100644
> --- a/tools/testing/selftests/resctrl/cmt_test.c
> +++ b/tools/testing/selftests/resctrl/cmt_test.c
> @@ -40,11 +40,11 @@ static int show_results_info(unsigned long sum_llc_val, int no_of_bits,
>  	int ret;
>  
>  	avg_llc_val = sum_llc_val / num_of_runs;
> -	avg_diff = (long)abs(cache_span - avg_llc_val);
> +	avg_diff = (long)(cache_span - avg_llc_val);
>  	diff_percent = ((float)cache_span - avg_llc_val) / cache_span * 100;
>  
>  	ret = platform && abs((int)diff_percent) > max_diff_percent &&
> -	      abs(avg_diff) > max_diff;
> +	      labs(avg_diff) > max_diff;
>  
>  	ksft_print_msg("%s Check cache miss rate within %lu%%\n",
>  		       ret ? "Fail:" : "Pass:", max_diff_percent);
> diff --git a/tools/testing/selftests/resctrl/mba_test.c b/tools/testing/selftests/resctrl/mba_test.c
> index 7946e32e85c8..5fffbc9ff6a4 100644
> --- a/tools/testing/selftests/resctrl/mba_test.c
> +++ b/tools/testing/selftests/resctrl/mba_test.c
> @@ -60,7 +60,7 @@ static bool show_mba_info(unsigned long *bw_imc, unsigned long *bw_resc)
>  	/* Memory bandwidth from 100% down to 10% */
>  	for (allocation = 0; allocation < ALLOCATION_MAX / ALLOCATION_STEP;
>  	     allocation++) {
> -		unsigned long avg_bw_imc, avg_bw_resc;
> +		long avg_bw_imc, avg_bw_resc;
>  		unsigned long sum_bw_imc = 0, sum_bw_resc = 0;

nit: since you are touching this line, could you please move it down one line to
establish reverse fir order?

>  		int avg_diff_per;
>  		float avg_diff;
> diff --git a/tools/testing/selftests/resctrl/mbm_test.c b/tools/testing/selftests/resctrl/mbm_test.c
> index d67ffa3ec63a..a4c3ea49b0e8 100644
> --- a/tools/testing/selftests/resctrl/mbm_test.c
> +++ b/tools/testing/selftests/resctrl/mbm_test.c
> @@ -17,7 +17,7 @@
>  static int
>  show_bw_info(unsigned long *bw_imc, unsigned long *bw_resc, size_t span)
>  {
> -	unsigned long avg_bw_imc = 0, avg_bw_resc = 0;
> +	long avg_bw_imc = 0, avg_bw_resc = 0;
>  	unsigned long sum_bw_imc = 0, sum_bw_resc = 0;
>  	int runs, ret, avg_diff_per;
>  	float avg_diff = 0;

Same nit here about reverse fir order.

Thank you very much for sticking with this to fix the warnings.
With the nitpicks addressed you can add:
| Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette