Date:   Mon, 23 Jan 2023 05:00:07 +0800
From:   kernel test robot <lkp@intel.com>
To:     Ajay Kaher <akaher@vmware.com>, rostedt@goodmis.org,
        mhiramat@kernel.org
Cc:     oe-kbuild-all@lists.linux.dev, linux-kernel@vger.kernel.org,
        linux-trace-kernel@vger.kernel.org, chinglinyu@google.com,
        namit@vmware.com, srivatsab@vmware.com, srivatsa@csail.mit.edu,
        amakhalov@vmware.com, vsirnapalli@vmware.com, tkundu@vmware.com,
        er.ajay.kaher@gmail.com, Ajay Kaher <akaher@vmware.com>
Subject: Re: [PATCH 8/8] eventfs: moving tracing/events to eventfs
Message-ID: <202301230402.yk3757pr-lkp@intel.com>
References: <1674407228-49109-8-git-send-email-akaher@vmware.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1674407228-49109-8-git-send-email-akaher@vmware.com>
Precedence: bulk

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@intel.com/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@intel.com>

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