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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?26qmSiQsIeLMJtd1Wjxg5ifOY7cK38Vg/WqZJi7k58vmHF/WJkcrqc9WYXIi?= =?us-ascii?Q?0f8M/Xzu83qZpLze/SVZLDu0T57zU3XYswVMPUhDiYz6AGhTEQ+8Vl9hvpeM?= =?us-ascii?Q?D5/omRUG1Lr0nGiULtOfD260PVztJw5UNFzs5KqGhzX4ngTApfOh0Oy2C1DJ?= =?us-ascii?Q?HLqVCWlrH1p5hGqtFkMl22vN9q0EMnLtEnwAIryOH8UaaemCNsE7wKhRGY5h?= =?us-ascii?Q?z/0agOgkvL99L7a9R/T+DbfbO1Iv/zfL4EdT71+3up+w2TTK+Z+fdcclqJua?= =?us-ascii?Q?M2oSg7RmsRQU5f1wHE7mdO/RoDtDtIciLLKmnp9tyWCccdxrgVuzRYzrC/T8?= =?us-ascii?Q?YbfXyxKtMOJqfWQRxs7vpvVxnw6BMi+N9EDsPkXpczivpnIEaeY7WpY9wr6C?= =?us-ascii?Q?8ii/Cn0dQcJb2kUQDcW8t3WSmuGX9GCMkJSKA3UyYgQF02lea1nQZzT0jAQd?= =?us-ascii?Q?tJox9n8WZMAtVjwAybTtp86i4Dswbrhu4kGuY2uexOV1Pfbz8iIa0IW1yd8K?= =?us-ascii?Q?wxxg093/fT7r/cc/9PLrGwVJZpAn4w+4iqZ3gGaEllGNstMzfKgrAFjpD13M?= =?us-ascii?Q?VvzWEmV5DCtAfDqG1SkeTGy7vi+jGqKRLEZQOtDfRsT29WeFTJ43SLCgeMZy?= =?us-ascii?Q?nBuXTsnumK+8e1kUjKc6qKOLJ/mmhT5b4ewmZT1J3z4vFGUFjSFGKvRFdnPo?= =?us-ascii?Q?jRoRMPRKbRt5qpbHYSS6Q2YWHNpFoYYNK18NUTr0OIotKD69rDiHjnUZ/8iQ?= =?us-ascii?Q?rvSpZE1V9fk0qIuiDfcysuey/dGZR0SoyIPvTvaatZKWtlFK1Eb+jsP9vVgV?= =?us-ascii?Q?Fwwk8qp/vVC89lElgM5jpK3Yc6GnmT0II+PLGnmov+RMTHOaYFmgwDBGi7bn?= =?us-ascii?Q?qVfjv+rXEGP2iY66C1hT40HiQbHmFkPW02bbb0uSzTkM/GQb2tixhu2EX0YQ?= =?us-ascii?Q?G7WMt1p7EqhrWh302IdcSQJErswMkNYlX4Kx/JaM3ppsPv/4r0t5rdH8+J5p?= =?us-ascii?Q?WV4lhjjk222M8lNjVWPZJapxH44/9vqInd97eVEri64d6XDXl4XfUR7r7iRn?= =?us-ascii?Q?8a3pY29ot867Pyr1TAFTZwlJDkOhoZMruRpTYfzSl2hQjYqdNkB5fp6EZnx2?= =?us-ascii?Q?LfMU4l+ZlP8SV25ROUENdV4AWL+4/kvY4RjJP0BbnMeaQPlr5tFJgVy76zG6?= =?us-ascii?Q?bgOGx5R7Kb7Z0DuO+itg/MC9RXqclCQB1yNRUQAASPC+gJIIqbfrY9M83xQD?= =?us-ascii?Q?DB0JgTHN2DZTJrOfKv/0oJL5NM++pMp+GcE5uHDD4Rr84cxM4TyG0JlxoH/2?= =?us-ascii?Q?n2t2X95nkvLqyS9gx3coZhlKdBWsDjrxpqSjA1JE1H4XHN+6ntz9IZKlZhB2?= =?us-ascii?Q?BtxFuWeEcXknHJnsvfCJyGKa/6H4QbWWbfloOSuJ26UBAfNWvP9sJlQEQ/Vw?= =?us-ascii?Q?5s8FQTPdk8s9rBtKSql3NSWGyBbqNlbZLMbAbFbm/cN6ggjVjuYCWC7KnrhI?= =?us-ascii?Q?7qJvxy7/4gYtCv+r1GnEuPFFSrUhLgo9qGsHFG7tPpE/A+oNk+7G5MLCUkOq?= =?us-ascii?Q?dczrfAn88NFeQ9uiIs5k6oKf0UtUmoCM7JBf6uuBz32OVtL6D/Cdl0tLcneo?= =?us-ascii?Q?tFKKVQwwFWEaCb00IYD045le7YnfBp2VDkj8UbZ0RdFsodQHMDSx7sEMUFSw?= =?us-ascii?Q?lg/yBiVFsI9WAUC+smS8CwnrXcfE7R6jg13oal2VZhjdZvV06IFMC6y3jvFI?= =?us-ascii?Q?FzG/avirqw=3D=3D?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: 5a45e441-3da7-4504-06d8-08de4a622a87 X-MS-Exchange-CrossTenant-AuthSource: SN7PR12MB8059.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 03 Jan 2026 00:51:01.4654 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: aqCi8ZRoQtGGPvDN+haozGZ93C/q3Z9tR+ywx93BM0lMlbFPLFHGIEhn/YcFQux/iX8D5J0pJgaXPlHs+axmDA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: CY5PR12MB6454 On Mon, Dec 29, 2025 at 11:17:48AM -0500, Steven Rostedt wrote: > On Sun, 28 Dec 2025 13:31:50 -0800 > Andrew Morton wrote: > > > > trace_printk() should be as available to the kernel as printk() is. > > > > um, why? trace_printk is used 1% as often as is printk. Seems > > reasonable to include a header file to access such a rarely-used(!) and > > specialized thing? > > It will waste a lot of kernel developers time. Go to conferences and talk > with developers. trace_printk() is now one of the most common ways to debug > your code. Having to add "#include " in every file > that you use trace_printk() (and after your build fails because you forgot > to include that file **WILL** slow down kernel debugging for hundreds of > developers! It *is* used more than printk() for debugging today. Because > it's fast and can be used in any context (NMI, interrupt handlers, etc). > > But sure, if you want to save the few minutes that is added to "make > allyesconfig" by sacrificing minutes of kernel developer's time. Go ahead > and make this change. > > I don't know how much you debug and develop today, but lots of people I > talk to at conferences thank me for trace_printk() because it makes > debugging their code so much easier. > > The "shotgun" approach is very common. That is, you add: > > trace_printk("%s:%d\n", __func__, __LINE__); > > all over your code to find out where things are going wrong. With the > persistent ring buffer, you can even extract that information after a > crash and reboot. I use trace_printk() all the time for kernel, particularly RCU development. One of the key usecases I have is dumping traces on panic (with panic on warn and stop tracing on warn enabled). This is extremely useful since I can add custom tracing and dump traces when rare conditions occur. I fixed several bugs with this technique. I also recommend keeping it convenient to use. thanks, - Joel