From: kernel test robot <lkp@intel.com>
To: Martin Weiss <martin.githubacc@gmail.com>, linux-kernel@vger.kernel.org
Cc: oe-kbuild-all@lists.linux.dev,
Martin Weiss <Martin.weiss2410@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH] trace_branch: use per-cpu counters for correct/incorrect stats
Date: Fri, 7 Aug 2026 00:53:24 +0800 [thread overview]
Message-ID: <202608070005.js0pMRDK-lkp@intel.com> (raw)
In-Reply-To: <20260629095838.601926-1-Martin.weiss2410@gmail.com>
Hi Martin,
kernel test robot noticed the following build warnings:
[auto build test WARNING on trace/for-next]
[also build test WARNING on linus/master v7.2-rc6 next-20260806]
[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/Martin-Weiss/trace_branch-use-per-cpu-counters-for-correct-incorrect-stats/20260806-093445
base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link: https://lore.kernel.org/r/20260629095838.601926-1-Martin.weiss2410%40gmail.com
patch subject: [PATCH] trace_branch: use per-cpu counters for correct/incorrect stats
config: arm64-randconfig-r062-20260806 (https://download.01.org/0day-ci/archive/20260807/202608070005.js0pMRDK-lkp@intel.com/config)
compiler: aarch64-linux-gcc (GCC) 13.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260807/202608070005.js0pMRDK-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202608070005.js0pMRDK-lkp@intel.com/
All warnings (new ones prefixed by >>):
kernel/trace/trace_branch.c: In function 'ftrace_likely_update':
>> kernel/trace/trace_branch.c:198:6: warning: infinite recursion detected [-Winfinite-recursion]
198 | void ftrace_likely_update(struct ftrace_likely_data *f, int val,
| ^~~~~~~~~~~~~~~~~~~~
In file included from include/linux/array_size.h:5,
from include/linux/kernel.h:16,
from include/linux/kallsyms.h:11,
from kernel/trace/trace_branch.c:7:
include/linux/compiler.h:33:25: note: recursive call
33 | ftrace_likely_update(&______f, ______r, \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
34 | expect, is_constant); \
| ~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:68:10: note: in definition of macro '__trace_if_value'
68 | (cond) ? \
| ^~~~
include/linux/compiler.h:55:28: note: in expansion of macro '__trace_if_var'
55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
| ^~~~~~~~~~~~~~
include/linux/preempt.h:238:9: note: in expansion of macro 'if'
238 | if (unlikely(__preempt_count_dec_and_test())) \
| ^~
include/linux/compiler.h:47:26: note: in expansion of macro '__branch_check__'
47 | # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
| ^~~~~~~~~~~~~~~~
include/linux/preempt.h:238:13: note: in expansion of macro 'unlikely'
238 | if (unlikely(__preempt_count_dec_and_test())) \
| ^~~~~~~~
arch/arm64/include/asm/percpu.h:160:9: note: in expansion of macro 'preempt_enable_notrace'
160 | preempt_enable_notrace(); \
| ^~~~~~~~~~~~~~~~~~~~~~
arch/arm64/include/asm/percpu.h:197:9: note: in expansion of macro '_pcp_protect'
197 | _pcp_protect(__percpu_add_case_64, pcp, val)
| ^~~~~~~~~~~~
include/linux/percpu-defs.h:372:25: note: in expansion of macro 'this_cpu_add_8'
372 | case 8: stem##8(variable, __VA_ARGS__);break; \
| ^~~~
include/linux/percpu-defs.h:501:41: note: in expansion of macro '__pcpu_size_call'
501 | #define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, pcp, val)
| ^~~~~~~~~~~~~~~~
include/linux/percpu-defs.h:511:41: note: in expansion of macro 'this_cpu_add'
511 | #define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
| ^~~~~~~~~~~~
kernel/trace/trace_branch.c:218:17: note: in expansion of macro 'this_cpu_inc'
218 | this_cpu_inc(f->data.correct);
| ^~~~~~~~~~~~
include/linux/compiler.h:33:25: note: recursive call
33 | ftrace_likely_update(&______f, ______r, \
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
34 | expect, is_constant); \
| ~~~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:68:10: note: in definition of macro '__trace_if_value'
68 | (cond) ? \
| ^~~~
include/linux/compiler.h:55:28: note: in expansion of macro '__trace_if_var'
55 | #define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) )
| ^~~~~~~~~~~~~~
include/linux/preempt.h:238:9: note: in expansion of macro 'if'
238 | if (unlikely(__preempt_count_dec_and_test())) \
| ^~
include/linux/compiler.h:47:26: note: in expansion of macro '__branch_check__'
47 | # define unlikely(x) (__branch_check__(x, 0, __builtin_constant_p(x)))
| ^~~~~~~~~~~~~~~~
include/linux/preempt.h:238:13: note: in expansion of macro 'unlikely'
238 | if (unlikely(__preempt_count_dec_and_test())) \
| ^~~~~~~~
arch/arm64/include/asm/percpu.h:160:9: note: in expansion of macro 'preempt_enable_notrace'
160 | preempt_enable_notrace(); \
| ^~~~~~~~~~~~~~~~~~~~~~
arch/arm64/include/asm/percpu.h:197:9: note: in expansion of macro '_pcp_protect'
197 | _pcp_protect(__percpu_add_case_64, pcp, val)
| ^~~~~~~~~~~~
include/linux/percpu-defs.h:372:25: note: in expansion of macro 'this_cpu_add_8'
372 | case 8: stem##8(variable, __VA_ARGS__);break; \
| ^~~~
include/linux/percpu-defs.h:501:41: note: in expansion of macro '__pcpu_size_call'
501 | #define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, pcp, val)
| ^~~~~~~~~~~~~~~~
include/linux/percpu-defs.h:511:41: note: in expansion of macro 'this_cpu_add'
511 | #define this_cpu_inc(pcp) this_cpu_add(pcp, 1)
| ^~~~~~~~~~~~
kernel/trace/trace_branch.c:220:17: note: in expansion of macro 'this_cpu_inc'
220 | this_cpu_inc(f->data.incorrect);
| ^~~~~~~~~~~~
vim +198 kernel/trace/trace_branch.c
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 197
134e6a034cb004 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-19 @198) void ftrace_likely_update(struct ftrace_likely_data *f, int val,
d45ae1f7041ac5 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-17 199) int expect, int is_constant)
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 200 {
4a6c91fbdef846 kernel/trace/trace_branch.c Peter Zijlstra 2019-03-07 201 unsigned long flags = user_access_save();
4a6c91fbdef846 kernel/trace/trace_branch.c Peter Zijlstra 2019-03-07 202
d45ae1f7041ac5 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-17 203) /* A constant is always correct */
134e6a034cb004 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-19 204) if (is_constant) {
134e6a034cb004 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-19 205) f->constant++;
d45ae1f7041ac5 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-17 206) val = expect;
134e6a034cb004 kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-19 207) }
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 208 /*
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 209 * I would love to have a trace point here instead, but the
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 210 * trace point code is so inundated with unlikely and likely
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 211 * conditions that the recursive nightmare that exists is too
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 212 * much to try to get working. At least for now.
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 213 */
068f530b3f274d kernel/trace/trace_branch.c Steven Rostedt (VMware 2017-01-19 214) trace_likely_condition(f, val, expect);
52f232cb720a7b kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 215
a53c1587fa9e39 kernel/trace/trace_branch.c Martin Weiss 2026-06-29 216 /* use per-cpu counters to avoid contention */
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 217 if (val == expect)
a53c1587fa9e39 kernel/trace/trace_branch.c Martin Weiss 2026-06-29 218 this_cpu_inc(f->data.correct);
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 219 else
a53c1587fa9e39 kernel/trace/trace_branch.c Martin Weiss 2026-06-29 220 this_cpu_inc(f->data.incorrect);
4a6c91fbdef846 kernel/trace/trace_branch.c Peter Zijlstra 2019-03-07 221
4a6c91fbdef846 kernel/trace/trace_branch.c Peter Zijlstra 2019-03-07 222 user_access_restore(flags);
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 223 }
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 224 EXPORT_SYMBOL(ftrace_likely_update);
1f0d69a9fc815d kernel/trace/trace_unlikely.c Steven Rostedt 2008-11-12 225
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
next prev parent reply other threads:[~2026-08-06 16:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-29 9:58 [PATCH] trace_branch: use per-cpu counters for correct/incorrect stats Martin Weiss
2026-06-29 10:47 ` Steven Rostedt
2026-08-06 16:53 ` kernel test robot [this message]
2026-08-06 19:38 ` kernel test robot
2026-08-06 20:04 ` kernel test robot
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