[mingo-tip:master 2009/2335] kernel/trace/trace_hwlat.c:174:6: warning: no previous prototype for function 'trace_hwlat_callback'

From: kernel test robot
Date: Thu Mar 17 2022 - 00:55:48 EST


tree: git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git master
head: 85293bf3fca6d85608cff1447ce3097583f15fab
commit: f3c1d292f157b79c05590971f8ae4b297bd60830 [2009/2335] headers/deps: Remove <linux/hardirq.h> inclusions from headers that don't need it anymore
config: x86_64-randconfig-a011-20220314 (https://download.01.org/0day-ci/archive/20220317/202203171104.4wcK0cRh-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project a6ec1e3d798f8eab43fb3a91028c6ab04e115fcb)
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://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git/commit/?id=f3c1d292f157b79c05590971f8ae4b297bd60830
git remote add mingo-tip git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git
git fetch --no-tags mingo-tip master
git checkout f3c1d292f157b79c05590971f8ae4b297bd60830
# save the config file to linux build tree
mkdir build_dir
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash kernel/trace/

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

All warnings (new ones prefixed by >>):

>> kernel/trace/trace_hwlat.c:174:6: warning: no previous prototype for function 'trace_hwlat_callback' [-Wmissing-prototypes]
void trace_hwlat_callback(bool enter)
^
kernel/trace/trace_hwlat.c:174:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void trace_hwlat_callback(bool enter)
^
static
1 warning generated.


vim +/trace_hwlat_callback +174 kernel/trace/trace_hwlat.c

e7c15cd8a113335 Steven Rostedt (Red Hat 2016-06-23 173)
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 @174) void trace_hwlat_callback(bool enter)
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 175) {
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 176 struct hwlat_kthread_data *kdata = get_cpu_data();
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 177
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 178 if (!kdata->kthread)
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 179) return;
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 180)
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 181) /*
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 182) * Currently trace_clock_local() calls sched_clock() and the
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 183) * generic version is not NMI safe.
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 184) */
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 185) if (!IS_ENABLED(CONFIG_GENERIC_SCHED_CLOCK)) {
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 186) if (enter)
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 187 kdata->nmi_ts_start = time_get();
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 188) else
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 189 kdata->nmi_total_ts += time_get() - kdata->nmi_ts_start;
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 190) }
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 191)
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 192) if (enter)
f46b16520a087e8 Daniel Bristot de Oliveira 2021-06-22 193 kdata->nmi_count++;
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 194) }
7b2c86250122de3 Steven Rostedt (Red Hat 2016-08-04 195)

:::::: The code at line 174 was first introduced by commit
:::::: 7b2c86250122de316cbab8754050622ead04af39 tracing: Add NMI tracing in hwlat detector

:::::: TO: Steven Rostedt (Red Hat) <rostedt@xxxxxxxxxxx>
:::::: CC: Steven Rostedt <rostedt@xxxxxxxxxxx>

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