Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <bf3cd367-81be-a72b-6f23-14005f308a1d@oracle.com>
Date:   Sun, 13 Mar 2022 11:35:49 +0530
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.6.1
Subject: Re: [PATCH] drm/v3d: Use kvcalloc
Content-Language: en-US
To:     Joe Perches <joe@perches.com>
Cc:     dan.carpenter@oracle.com, Emma Anholt <emma@anholt.net>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org
References: <20220312152656.51625-1-harshit.m.mogalapalli@oracle.com>
 <05dbfbd2670e2b28229d0ab96c1bd99787d4a187.camel@perches.com>
From:   Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
In-Reply-To: <05dbfbd2670e2b28229d0ab96c1bd99787d4a187.camel@perches.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0: =?utf-8?B?QytzcVBXalRHNlZhSmNSWDZ5anJmcnV6eGlKUXQ1TTRtaTdvQXZXSnhsbTVU?=
 =?utf-8?B?ZFE2NVAvSG5ZNjRYQldyTWFXa3RWbWc4cmZMOS90SUJoY3FsYUNWMHY0aUkx?=
 =?utf-8?B?eFMvNXRmOFlUVmtEbVJteHdzS1QxMHRDL3IxT3k0VGRlV09HTkkyOHZrOWxu?=
 =?utf-8?B?eG4wZ3dsTlpwUDcySmRzTWZXL2lLQ0lUZjEzRTMyUy8ySGRRdEpxWXlDSEQy?=
 =?utf-8?B?RFJzSDN2Nmd5VEo4L3BBQlprUzVhTXJFeWlxam9aM0xTYnZUT3RpSWpxS081?=
 =?utf-8?B?dmswcHcvcEJ5LzBiNmIwZUo3UHhnZXBFK2RncUxEbno2c3ZMZ05SRzU3V3Yw?=
 =?utf-8?B?NHVRazFyMXFvcVBLMDdicXdZaHlMK0FTdHRFSG5WZmMvZ09STlplMEN6SGxT?=
 =?utf-8?B?bGM1WkdVbGxhaS8zdUhkcVdMMHJmbzFmekFvTXR0ZGFUdE9iN2c5a29HazNT?=
 =?utf-8?B?MVRJTU0vS0tWZkdONlQvNWd1NzBrQklEaUgydTRIZWR0bmVaelEvSXhlVFZQ?=
 =?utf-8?B?dEVqWDN0Y3JpUlREdlNrWDZjeXpiSTYxMU5SZ0ZuUlZvcW5sZEZjQUpDcEh3?=
 =?utf-8?B?Qk5HNVAvenlrVFBRWUxtd0pmWjMvVUM5d2laTHBvazFmSUQ2Rk1ZY2J4dU8x?=
 =?utf-8?B?S1VScHJiOHdUYXMzMXJVMkdYb0RpcHVEZEVONWJtMVpyc0haRm5JQWZRUXpT?=
 =?utf-8?B?Z1gwVHJmSjF1djFuc1pjNWQyamtHaEpjSGVCVjJUTjZNUnJ2Z01ubkt0SzFX?=
 =?utf-8?B?bzdpS3g3YXJqK2ptai90c2RKSndVOFY2aGhxZ3JweW4xMTJPRGxCd0xjUUo0?=
 =?utf-8?B?YWp4alR2UG9vR1d0NHdqczFnc0RmRzdOaHVzdFhGcWhhM3k1L0xORzk4SDQ4?=
 =?utf-8?B?SmZ4YlBVWllhMjdrV2k0L2xCdUVHMk5KdXBJREwzL0VaQTBZQzlJZ1gxMys3?=
 =?utf-8?B?OStJbDYzTk9vSjBqbXR2bGs5UjFpKzcrWUpicWRYRnBTY1pteDRRVGJXdCtH?=
 =?utf-8?B?TzBFMGVyd1FkMXZsZTVDSWxESDNSOVZQQjlCaU5KREFvMXZUeHJOeXkrbkJY?=
 =?utf-8?B?OHY4aFl2ME9jRk9kajltQkdrc2I0UmIzTnQrMWdYUllIQnFUUlh6cE9SNldJ?=
 =?utf-8?B?eGFtQmlPS1ZPbm5rV3FXMlNMYkNybHQrQUpWTExwZE5CbzFpOWZMOVp5VTdM?=
 =?utf-8?B?U0pYYWZpRVU0RC9hLzlvc2I4Q1ZBV0FOZVpDWU9jVmdVdCt5bHc4ZEh2KzJ0?=
 =?utf-8?B?T2NjV3hLamhmV2hQOCtrS0xNVTQrVjB2K3ZYbUJwQ2g5bmpHcDQwVUNkV3ND?=
 =?utf-8?B?UC9JOW42VUZpdlhmRmFwQjFuanI2RHFZaGczYXdPWkFwbEpUS3BlYkJ5Wncr?=
 =?utf-8?B?cTlkcGQ4eGZGQkdQRFZwSVJPZzNpbm9aWXgyLzhrT1RHS0oxQWJlTk9zdG04?=
 =?utf-8?B?ZGM2dGViT3d1MzFvd01XVHViRGRRZ21zSE5uNWZESFp4cXJkenVHb0t4TXdJ?=
 =?utf-8?B?NUJIN3Z2RkNuejFmc3ZZd0lxSjdnY0JMZThxTTBtbjFkcTM1a0dLMGRURWM4?=
 =?utf-8?B?RndyN3JvLzVQRHl4eEdmdHlvUENuWUNsWDBYS3lJQjYxdkkxejh4RXZLV0lh?=
 =?utf-8?B?NldTZlc2dlVkVG50TDR1dWcrVll6VFB6RFhqMm5KRnU4bkc1SjZmT2c2dVZ2?=
 =?utf-8?B?UHlEWU02MFlXc3dEVHZKVjU5eS9Ud3NnMXkwdGVJZEIrTnluaFM2cjVqWjBP?=
 =?utf-8?B?K2ErMXdyNGlCc3AwMFMzQ3R6eXJYdzJvTWpTQVhBeXZmbnNpKzhoOFJHRjNV?=
 =?utf-8?B?NDBEaHhZQiszelp2Y25xRkllZVBRZ1FzNEV2N3E3SXoyNWZYampub3NhSkkw?=
 =?utf-8?B?bFZNOVM2MjhCSjNtMjNtYXBMNy9EUnlBUHlKZzBKaG43MlZ1T2NQTmJlWGg5?=
 =?utf-8?B?RzlzSjlBaUFXUTdKcWZTdjZhNjkvY1NFSFR1YTZ2VTBjaHY2MXNWdnZZMis5?=
 =?utf-8?Q?gE/4n/cFDZ+IWv9mcpMCGIV1vqXe4g=3D?=
X-OriginatorOrg: oracle.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 34c16b56-3217-4efb-ca9e-08da04b78c77
X-MS-Exchange-CrossTenant-AuthSource: MN2PR10MB4191.namprd10.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Mar 2022 06:06:00.9627
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 4e2c6054-71cb-48f1-bd6c-3a9705aca71b
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: YELeMy9EcqZETF311uPB8RGLM8CSQmp6tSgIwJf9e8evcznx0HtxTBCAq+dDqehNYlvcER6CX1n9bExo5oh4f9xJ6qJwV+Qvsjiv0hFRg6w+yrizRt8f293psBJ9BNO/
X-MS-Exchange-Transport-CrossTenantHeadersStamped: DS7PR10MB5263
X-Proofpoint-Virus-Version: vendor=nai engine=6300 definitions=10284 signatures=693139
X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 bulkscore=0 mlxscore=0 phishscore=0
 adultscore=0 malwarescore=0 spamscore=0 suspectscore=0 mlxlogscore=750
 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2202240000
 definitions=main-2203130035
X-Proofpoint-GUID: txQifhLfNIk2d3JO60wnHmxYi65K1ZUO
X-Proofpoint-ORIG-GUID: txQifhLfNIk2d3JO60wnHmxYi65K1ZUO
X-Spam-Status: No, score=-2.8 required=5.0 tests=BAYES_00,DKIM_SIGNED,
        DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,NICE_REPLY_A,RCVD_IN_DNSWL_LOW,
        RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE,
        T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
        lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

Hi Joe,

On 13/03/22 3:57 am, Joe Perches wrote:
> On Sat, 2022-03-12 at 07:26 -0800, Harshit Mogalapalli wrote:
>> kvcalloc is same as kvmalloc_array + __GFP_ZERO.
> []
>> diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
> []
>> @@ -308,9 +308,8 @@ v3d_lookup_bos(struct drm_device *dev,
>>   		return -EINVAL;
>>   	}
>>   
>> -	job->bo = kvmalloc_array(job->bo_count,
>> -				 sizeof(struct drm_gem_cma_object *),
>> -				 GFP_KERNEL | __GFP_ZERO);
>> +	job->bo = kvcalloc(job->bo_count, sizeof(struct drm_gem_cma_object *),
>> +			   GFP_KERNEL);
>>   	if (!job->bo) {
>>   		DRM_DEBUG("Failed to allocate validated BO pointers\n");
>>   		return -ENOMEM;
> 
> trivia:
> 
> The DRM_DEBUG could also be removed as the the alloc will do a
> a dump_stack on failure.
> 
> 
Thanks for sharing your comments.

DRM_DEBUG statements are present in other parts of code as well. So 
didnot remove it.

Example below:
drivers/gpu/drm/v3d/v3d_gem.c at 322.

  311         job->bo = kvmalloc_array(job->bo_count,
  312                                  sizeof(struct drm_gem_cma_object *),
  313                                  GFP_KERNEL | __GFP_ZERO);
  314         if (!job->bo) {
  315                 DRM_DEBUG("Failed to allocate validated BO 
pointers\n");
  316                 return -ENOMEM;
  317         }
  318
  319         handles = kvmalloc_array(job->bo_count, sizeof(u32), 
GFP_KERNEL);
  320         if (!handles) {
  321                 ret = -ENOMEM;
  322                 DRM_DEBUG("Failed to allocate incoming GEM 
handles\n");
  323                 goto fail;
  324         }


Regards,
Harshit