Re: [PATCH 05/12] tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled
From: kernel test robot
Date: Mon May 05 2025 - 01:06:32 EST
Hi Steven,
kernel test robot noticed the following build warnings:
[auto build test WARNING on trace/for-next]
[also build test WARNING on linus/master v6.15-rc4 next-20250502]
[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/Steven-Rostedt/tracing-mmiotrace-Remove-reference-to-unused-per-CPU-data-pointer/20250503-050317
base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link: https://lore.kernel.org/r/20250502205348.643055437%40goodmis.org
patch subject: [PATCH 05/12] tracing: kdb: Use tracer_tracing_on/off() instead of setting per CPU disabled
config: arc-randconfig-002-20250503 (https://download.01.org/0day-ci/archive/20250505/202505051213.exaXF8qp-lkp@xxxxxxxxx/config)
compiler: arc-linux-gcc (GCC) 11.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250505/202505051213.exaXF8qp-lkp@xxxxxxxxx/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202505051213.exaXF8qp-lkp@xxxxxxxxx/
All warnings (new ones prefixed by >>):
kernel/trace/trace_kdb.c: In function 'kdb_ftdump':
>> kernel/trace/trace_kdb.c:101:13: warning: unused variable 'cpu' [-Wunused-variable]
101 | int cpu;
| ^~~
vim +/cpu +101 kernel/trace/trace_kdb.c
955b61e5979847 Jason Wessel 2010-08-05 91
955b61e5979847 Jason Wessel 2010-08-05 92 /*
955b61e5979847 Jason Wessel 2010-08-05 93 * kdb_ftdump - Dump the ftrace log buffer
955b61e5979847 Jason Wessel 2010-08-05 94 */
955b61e5979847 Jason Wessel 2010-08-05 95 static int kdb_ftdump(int argc, const char **argv)
955b61e5979847 Jason Wessel 2010-08-05 96 {
dbfe67334a1767 Douglas Anderson 2019-03-19 97 int skip_entries = 0;
19063c776fe745 Jason Wessel 2010-08-05 98 long cpu_file;
0c10cc2435115c Yuran Pereira 2024-10-28 99 int err;
03197fc02b3566 Douglas Anderson 2019-03-19 100 int cnt;
03197fc02b3566 Douglas Anderson 2019-03-19 @101 int cpu;
955b61e5979847 Jason Wessel 2010-08-05 102
19063c776fe745 Jason Wessel 2010-08-05 103 if (argc > 2)
955b61e5979847 Jason Wessel 2010-08-05 104 return KDB_ARGCOUNT;
955b61e5979847 Jason Wessel 2010-08-05 105
0c10cc2435115c Yuran Pereira 2024-10-28 106 if (argc && kstrtoint(argv[1], 0, &skip_entries))
0c10cc2435115c Yuran Pereira 2024-10-28 107 return KDB_BADINT;
955b61e5979847 Jason Wessel 2010-08-05 108
19063c776fe745 Jason Wessel 2010-08-05 109 if (argc == 2) {
0c10cc2435115c Yuran Pereira 2024-10-28 110 err = kstrtol(argv[2], 0, &cpu_file);
0c10cc2435115c Yuran Pereira 2024-10-28 111 if (err || cpu_file >= NR_CPUS || cpu_file < 0 ||
19063c776fe745 Jason Wessel 2010-08-05 112 !cpu_online(cpu_file))
19063c776fe745 Jason Wessel 2010-08-05 113 return KDB_BADINT;
19063c776fe745 Jason Wessel 2010-08-05 114 } else {
ae3b5093ad6004 Steven Rostedt 2013-01-23 115 cpu_file = RING_BUFFER_ALL_CPUS;
19063c776fe745 Jason Wessel 2010-08-05 116 }
19063c776fe745 Jason Wessel 2010-08-05 117
955b61e5979847 Jason Wessel 2010-08-05 118 kdb_trap_printk++;
03197fc02b3566 Douglas Anderson 2019-03-19 119
03197fc02b3566 Douglas Anderson 2019-03-19 120 trace_init_global_iter(&iter);
03197fc02b3566 Douglas Anderson 2019-03-19 121 iter.buffer_iter = buffer_iter;
03197fc02b3566 Douglas Anderson 2019-03-19 122
6a4611f6bb763d Steven Rostedt 2025-05-02 123 tracer_tracing_off(iter.tr);
03197fc02b3566 Douglas Anderson 2019-03-19 124
03197fc02b3566 Douglas Anderson 2019-03-19 125 /* A negative skip_entries means skip all but the last entries */
03197fc02b3566 Douglas Anderson 2019-03-19 126 if (skip_entries < 0) {
03197fc02b3566 Douglas Anderson 2019-03-19 127 if (cpu_file == RING_BUFFER_ALL_CPUS)
03197fc02b3566 Douglas Anderson 2019-03-19 128 cnt = trace_total_entries(NULL);
03197fc02b3566 Douglas Anderson 2019-03-19 129 else
03197fc02b3566 Douglas Anderson 2019-03-19 130 cnt = trace_total_entries_cpu(NULL, cpu_file);
03197fc02b3566 Douglas Anderson 2019-03-19 131 skip_entries = max(cnt + skip_entries, 0);
03197fc02b3566 Douglas Anderson 2019-03-19 132 }
03197fc02b3566 Douglas Anderson 2019-03-19 133
dbfe67334a1767 Douglas Anderson 2019-03-19 134 ftrace_dump_buf(skip_entries, cpu_file);
03197fc02b3566 Douglas Anderson 2019-03-19 135
6a4611f6bb763d Steven Rostedt 2025-05-02 136 tracer_tracing_on(iter.tr);
03197fc02b3566 Douglas Anderson 2019-03-19 137
955b61e5979847 Jason Wessel 2010-08-05 138 kdb_trap_printk--;
955b61e5979847 Jason Wessel 2010-08-05 139
955b61e5979847 Jason Wessel 2010-08-05 140 return 0;
955b61e5979847 Jason Wessel 2010-08-05 141 }
955b61e5979847 Jason Wessel 2010-08-05 142
--
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