Hi Mike, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on vhost/linux-next] [also build test WARNING on linux/master linus/master v5.13-rc7] [cannot apply to next-20210623] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Mike-Christie/kthread-pass-in-us... base: https://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost.git linux-next config: um-x86_64_defconfig (attached as .config) compiler: gcc-9 (Debian 9.3.0-22) 9.3.0 reproduce (this is a W=1 build): # https://github.com/0day-ci/linux/commit/9b4a744e588ed25e06eed415174977e75... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Mike-Christie/kthread-pass-in-user-and-check-RLIMIT_NPROC/20210624-110925 git checkout 9b4a744e588ed25e06eed415174977e7533b24dc # save the attached .config to linux build tree make W=1 ARCH=um SUBARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): cc1: warning: arch/um/include/uapi: No such file or directory [-Wmissing-include-dirs] kernel/kthread.c: In function 'kthread_create_for_user': 466 | namefmt, args); | ^~~~~~~ vim +466 kernel/kthread.c 443 444 /** 445 * kthread_create_for_user - create a kthread and check @user's RLIMIT_NPROC 446 * @threadfn: the function to run until signal_pending(current). 447 * @data: data ptr for @threadfn. 448 * @user: user_struct that will have its RLIMIT_NPROC checked 449 * @namefmt: printf-style name for the thread. 450 * 451 * This will create a kthread on the current node, leaving it in the stopped 452 * state. This is just a helper for kthread_create_on_node() that will check 453 * @user's process count against its RLIMIT_NPROC. See the 454 * kthread_create_on_node() documentation for more details. 455 */ 456 struct task_struct *kthread_create_for_user(int (*threadfn)(void *data), 457 void *data, 458 struct user_struct *user, 459 const char namefmt[], ...) 460 { 461 struct task_struct *task; 462 va_list args; 463 464 va_start(args, namefmt); 465 task = __kthread_create_on_node(threadfn, data, NUMA_NO_NODE, user, 467 va_end(args); 468 469 return task; 470 } 471 EXPORT_SYMBOL(kthread_create_for_user); 472 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org