Re: [PATCH 8/8] eventfs: moving tracing/events to eventfs

From: kernel test robot
Date: Sun Jan 22 2023 - 16:00:51 EST


Hi Ajay,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v6.2-rc5 next-20230120]
[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#_base_tree_information]

url: https://github.com/intel-lab-lkp/linux/commits/Ajay-Kaher/eventfs-adding-eventfs-dir-add-functions/20230123-010956
patch link: https://lore.kernel.org/r/1674407228-49109-8-git-send-email-akaher%40vmware.com
patch subject: [PATCH 8/8] eventfs: moving tracing/events to eventfs
config: arc-defconfig (https://download.01.org/0day-ci/archive/20230123/202301230402.yk3757pr-lkp@xxxxxxxxx/config)
compiler: arc-elf-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/be995c36ba2232edcd4fa64e4581b9a6763c75e6
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Ajay-Kaher/eventfs-adding-eventfs-dir-add-functions/20230123-010956
git checkout be995c36ba2232edcd4fa64e4581b9a6763c75e6
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arc SHELL=/bin/bash kernel/trace/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

kernel/trace/trace_events.c: In function 'event_create_dir':
>> kernel/trace/trace_events.c:2405:24: warning: variable 'd_events' set but not used [-Wunused-but-set-variable]
2405 | struct dentry *d_events;
| ^~~~~~~~


vim +/d_events +2405 kernel/trace/trace_events.c

ac343da7bc9048 Masami Hiramatsu 2020-09-10 2398
1473e4417c79f1 Steven Rostedt 2009-02-24 2399 static int
7f1d2f8210195c Steven Rostedt (Red Hat 2015-05-05 2400) event_create_dir(struct dentry *parent, struct trace_event_file *file)
1473e4417c79f1 Steven Rostedt 2009-02-24 2401 {
2425bcb9240f8c Steven Rostedt (Red Hat 2015-05-05 2402) struct trace_event_call *call = file->event_call;
ae63b31e4d0e2e Steven Rostedt 2012-05-03 2403 struct trace_array *tr = file->tr;
be995c36ba2232 Ajay Kaher 2023-01-22 2404 struct eventfs_file *ef_subsystem = NULL;
ae63b31e4d0e2e Steven Rostedt 2012-05-03 @2405 struct dentry *d_events;
de7b2973903c6c Mathieu Desnoyers 2014-04-08 2406 const char *name;
fd99498989f3b3 Steven Rostedt 2009-02-28 2407 int ret;
1473e4417c79f1 Steven Rostedt 2009-02-24 2408
6ecc2d1ca39177 Steven Rostedt 2009-02-27 2409 /*
6ecc2d1ca39177 Steven Rostedt 2009-02-27 2410 * If the trace point header did not define TRACE_SYSTEM
6ecc2d1ca39177 Steven Rostedt 2009-02-27 2411 * then the system would be called "TRACE_SYSTEM".
6ecc2d1ca39177 Steven Rostedt 2009-02-27 2412 */
ae63b31e4d0e2e Steven Rostedt 2012-05-03 2413 if (strcmp(call->class->system, TRACE_SYSTEM) != 0) {
be995c36ba2232 Ajay Kaher 2023-01-22 2414 ef_subsystem = event_subsystem_dir(tr, call->class->system, file, parent);
be995c36ba2232 Ajay Kaher 2023-01-22 2415 if (!ef_subsystem)
ae63b31e4d0e2e Steven Rostedt 2012-05-03 2416 return -ENOMEM;
ae63b31e4d0e2e Steven Rostedt 2012-05-03 2417 } else
ae63b31e4d0e2e Steven Rostedt 2012-05-03 2418 d_events = parent;
6ecc2d1ca39177 Steven Rostedt 2009-02-27 2419
687fcc4aee4567 Steven Rostedt (Red Hat 2015-05-13 2420) name = trace_event_name(call);
be995c36ba2232 Ajay Kaher 2023-01-22 2421 file->ef = eventfs_add_dir(name, ef_subsystem);
be995c36ba2232 Ajay Kaher 2023-01-22 2422 if (IS_ERR(file->ef)) {
8434dc9340cd2e Steven Rostedt (Red Hat 2015-01-20 2423) pr_warn("Could not create tracefs '%s' directory\n", name);
1473e4417c79f1 Steven Rostedt 2009-02-24 2424 return -1;
1473e4417c79f1 Steven Rostedt 2009-02-24 2425 }
1473e4417c79f1 Steven Rostedt 2009-02-24 2426
9b63776fa3ca96 Steven Rostedt 2012-05-10 2427 if (call->class->reg && !(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
be995c36ba2232 Ajay Kaher 2023-01-22 2428 eventfs_add_file("enable", TRACE_MODE_WRITE, file->ef, file,
620a30e97febc8 Oleg Nesterov 2013-07-31 2429 &ftrace_enable_fops);
1473e4417c79f1 Steven Rostedt 2009-02-24 2430

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests