Similar to the IRQ tracepoint, the preempt tracepoints are typically
disabled in production systems due to the significant overhead they
introduce even when not in use.
The overhead primarily comes from two sources: First, when tracepoints
are compiled into the kernel, preempt_count_add() and preempt_count_sub()
become external function calls rather than inlined operations. Second,
these functions perform unnecessary preempt_count() checks even when the
tracepoint itself is disabled.
This optimization introduces an early check of the tracepoint static key,
which allows us to skip both the function call overhead and the redundant
preempt_count() checks when tracing is disabled. The change maintains all
existing functionality when tracing is active while significantly
reducing overhead for the common case where tracing is inactive.
Signed-off-by: Wander Lairson Costa <wander@redhat.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
---
include/linux/preempt.h | 35 ++++++++++++++++++++++++++++++---
kernel/sched/core.c | 12 +----------
kernel/trace/trace_preemptirq.c | 19 ++++++++++++++++++
3 files changed, 52 insertions(+), 14 deletions(-)
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index b0af8d4ef6e6..d13c755cd934 100644
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -10,6 +10,7 @@
#include <linux/linkage.h>
#include <linux/cleanup.h>
#include <linux/types.h>
+#include <linux/tracepoint-defs.h>
/*
* We put the hardirq and softirq counter into the preemption
@@ -191,17 +192,45 @@ static __always_inline unsigned char interrupt_context_level(void)
*/
#define in_atomic_preempt_off() (preempt_count() != PREEMPT_DISABLE_OFFSET)
-#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_TRACE_PREEMPT_TOGGLE)
+#if defined(CONFIG_DEBUG_PREEMPT)
extern void preempt_count_add(int val);
extern void preempt_count_sub(int val);
-#define preempt_count_dec_and_test() \
- ({ preempt_count_sub(1); should_resched(0); })
+#elif defined(CONFIG_TRACE_PREEMPT_TOGGLE)
+extern void __trace_preempt_on(void);
+extern void __trace_preempt_off(void);
+
+DECLARE_TRACEPOINT(preempt_enable);
+DECLARE_TRACEPOINT(preempt_disable);
+
+#define __preempt_trace_enabled(type) \
+ (tracepoint_enabled(preempt_##type) && preempt_count() == val)
+
+static inline void preempt_count_add(int val)
+{
+ __preempt_count_add(val);
+
+ if (__preempt_trace_enabled(disable))
+ __trace_preempt_off();
+}
+
+static inline void preempt_count_sub(int val)
+{
+ if (__preempt_trace_enabled(enable))
+ __trace_preempt_on();
+
+ __preempt_count_sub(val);
+}
#else
#define preempt_count_add(val) __preempt_count_add(val)
#define preempt_count_sub(val) __preempt_count_sub(val)
#define preempt_count_dec_and_test() __preempt_count_dec_and_test()
#endif
+#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_TRACE_PREEMPT_TOGGLE)
+#define preempt_count_dec_and_test() \
+ ({ preempt_count_sub(1); should_resched(0); })
+#endif
+
#define __preempt_count_inc() __preempt_count_add(1)
#define __preempt_count_dec() __preempt_count_sub(1)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8988d38d46a3..4feba4738d79 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -5840,8 +5840,7 @@ static inline void sched_tick_start(int cpu) { }
static inline void sched_tick_stop(int cpu) { }
#endif
-#if defined(CONFIG_PREEMPTION) && (defined(CONFIG_DEBUG_PREEMPT) || \
- defined(CONFIG_TRACE_PREEMPT_TOGGLE))
+#if defined(CONFIG_PREEMPTION) && defined(CONFIG_DEBUG_PREEMPT)
/*
* If the value passed in is equal to the current preempt count
* then we just disabled preemption. Start timing the latency.
@@ -5850,30 +5849,24 @@ static inline void preempt_latency_start(int val)
{
if (preempt_count() == val) {
unsigned long ip = get_lock_parent_ip();
-#ifdef CONFIG_DEBUG_PREEMPT
current->preempt_disable_ip = ip;
-#endif
trace_preempt_off(CALLER_ADDR0, ip);
}
}
void preempt_count_add(int val)
{
-#ifdef CONFIG_DEBUG_PREEMPT
/*
* Underflow?
*/
if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0)))
return;
-#endif
__preempt_count_add(val);
-#ifdef CONFIG_DEBUG_PREEMPT
/*
* Spinlock count overflowing soon?
*/
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
-#endif
preempt_latency_start(val);
}
EXPORT_SYMBOL(preempt_count_add);
@@ -5891,7 +5884,6 @@ static inline void preempt_latency_stop(int val)
void preempt_count_sub(int val)
{
-#ifdef CONFIG_DEBUG_PREEMPT
/*
* Underflow?
*/
@@ -5903,14 +5895,12 @@ void preempt_count_sub(int val)
if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) &&
!(preempt_count() & PREEMPT_MASK)))
return;
-#endif
preempt_latency_stop(val);
__preempt_count_sub(val);
}
EXPORT_SYMBOL(preempt_count_sub);
NOKPROBE_SYMBOL(preempt_count_sub);
-
#else
static inline void preempt_latency_start(int val) { }
static inline void preempt_latency_stop(int val) { }
diff --git a/kernel/trace/trace_preemptirq.c b/kernel/trace/trace_preemptirq.c
index 90ee65db4516..deb2428b34a2 100644
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -118,6 +118,25 @@ EXPORT_TRACEPOINT_SYMBOL(irq_enable);
#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
+#if !defined(CONFIG_DEBUG_PREEMPT)
+EXPORT_SYMBOL(__tracepoint_preempt_disable);
+EXPORT_SYMBOL(__tracepoint_preempt_enable);
+
+void __trace_preempt_on(void)
+{
+ trace_preempt_on(CALLER_ADDR0, get_lock_parent_ip());
+}
+EXPORT_SYMBOL(__trace_preempt_on);
+NOKPROBE_SYMBOL(__trace_preempt_on);
+
+void __trace_preempt_off(void)
+{
+ trace_preempt_off(CALLER_ADDR0, get_lock_parent_ip());
+}
+EXPORT_SYMBOL(__trace_preempt_off);
+NOKPROBE_SYMBOL(__trace_preempt_off);
+#endif /* !CONFIG_DEBUG_PREEMPT */
+
void trace_preempt_on(unsigned long a0, unsigned long a1)
{
trace(preempt_enable, TP_ARGS(a0, a1));
--
2.50.0Hi Wander,
kernel test robot noticed the following build warnings:
[auto build test WARNING on trace/for-next]
[also build test WARNING on tip/sched/core linus/master v6.16-rc3 next-20250627]
[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/Wander-Lairson-Costa/trace-preemptirq-reduce-overhead-of-irq_enable-disable-tracepoints/20250626-222438
base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link: https://lore.kernel.org/r/20250626142017.26372-3-wander%40redhat.com
patch subject: [PATCH 2/2] tracing/preemptirq: Optimize preempt_disable/enable() tracepoint overhead
config: sparc64-randconfig-001-20250628 (https://download.01.org/0day-ci/archive/20250628/202506282232.13AjjGxr-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 8.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250628/202506282232.13AjjGxr-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/202506282232.13AjjGxr-lkp@intel.com/
All warnings (new ones prefixed by >>):
In file included from include/asm-generic/cmpxchg-local.h:6,
from arch/sparc/include/asm/cmpxchg_64.h:111,
from arch/sparc/include/asm/cmpxchg.h:5,
from arch/sparc/include/asm/atomic_64.h:12,
from arch/sparc/include/asm/atomic.h:5,
from include/linux/atomic.h:7,
from include/linux/tracepoint-defs.h:11,
from include/linux/preempt.h:13,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/resource.c:17:
include/linux/irqflags.h:201:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_enable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:201:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
>> include/linux/irqflags.h:201:1: warning: parameter names (without types) in function declaration
include/linux/irqflags.h:202:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_disable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:202:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
include/linux/irqflags.h:202:1: warning: parameter names (without types) in function declaration
In file included from include/linux/preempt.h:11,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/resource.c:17:
include/linux/irqflags.h: In function 'class_irq_destructor':
include/linux/irqflags.h:206:7: error: implicit declaration of function 'tracepoint_enabled'; did you mean 'local_irq_enable'? [-Werror=implicit-function-declaration]
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: note: each undeclared identifier is reported only once for each function it appears in
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irq_constructor':
include/linux/irqflags.h:215:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:26: note: in expansion of macro 'local_irq_disable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_destructor':
include/linux/irqflags.h:230:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_enable) && \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:277:7: note: in expansion of macro 'local_irq_restore'
local_irq_restore(_T->flags),
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_constructor':
include/linux/irqflags.h:223:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:276:7: note: in expansion of macro 'local_irq_save'
local_irq_save(_T->flags),
^~~~~~~~~~~~~~
In file included from include/linux/static_key.h:1,
from include/linux/tracepoint-defs.h:12,
from include/linux/preempt.h:13,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/resource.c:17:
include/linux/spinlock_api_smp.h: In function '__raw_spin_lock_irqsave':
include/linux/tracepoint-defs.h:92:27: error: '__tracepoint_irq_disable' undeclared (first use in this function); did you mean 'raw_local_irq_disable'?
static_branch_unlikely(&(__tracepoint_##tp).key)
^~~~~~~~~~~~~
include/linux/jump_label.h:503:43: note: in definition of macro 'static_branch_unlikely'
--
In file included from include/asm-generic/cmpxchg-local.h:6,
from arch/sparc/include/asm/cmpxchg_64.h:111,
from arch/sparc/include/asm/cmpxchg.h:5,
from arch/sparc/include/asm/atomic_64.h:12,
from arch/sparc/include/asm/atomic.h:5,
from include/linux/atomic.h:7,
from include/linux/tracepoint-defs.h:11,
from include/linux/preempt.h:13,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/fork.c:16:
include/linux/irqflags.h:201:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_enable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:201:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
>> include/linux/irqflags.h:201:1: warning: parameter names (without types) in function declaration
include/linux/irqflags.h:202:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_disable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:202:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
include/linux/irqflags.h:202:1: warning: parameter names (without types) in function declaration
In file included from include/linux/preempt.h:11,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/fork.c:16:
include/linux/irqflags.h: In function 'class_irq_destructor':
include/linux/irqflags.h:206:7: error: implicit declaration of function 'tracepoint_enabled'; did you mean 'local_irq_enable'? [-Werror=implicit-function-declaration]
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: note: each undeclared identifier is reported only once for each function it appears in
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irq_constructor':
include/linux/irqflags.h:215:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:26: note: in expansion of macro 'local_irq_disable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_destructor':
include/linux/irqflags.h:230:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_enable) && \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:277:7: note: in expansion of macro 'local_irq_restore'
local_irq_restore(_T->flags),
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_constructor':
include/linux/irqflags.h:223:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:276:7: note: in expansion of macro 'local_irq_save'
local_irq_save(_T->flags),
^~~~~~~~~~~~~~
In file included from include/linux/static_key.h:1,
from include/linux/tracepoint-defs.h:12,
from include/linux/preempt.h:13,
from include/linux/spinlock.h:56,
from include/linux/mmzone.h:8,
from include/linux/gfp.h:7,
from include/linux/slab.h:16,
from kernel/fork.c:16:
include/linux/spinlock_api_smp.h: In function '__raw_spin_lock_irqsave':
include/linux/tracepoint-defs.h:92:27: error: '__tracepoint_irq_disable' undeclared (first use in this function); did you mean 'raw_local_irq_disable'?
static_branch_unlikely(&(__tracepoint_##tp).key)
^~~~~~~~~~~~~
include/linux/jump_label.h:503:43: note: in definition of macro 'static_branch_unlikely'
--
In file included from include/asm-generic/cmpxchg-local.h:6,
from arch/sparc/include/asm/cmpxchg_64.h:111,
from arch/sparc/include/asm/cmpxchg.h:5,
from arch/sparc/include/asm/atomic_64.h:12,
from arch/sparc/include/asm/atomic.h:5,
from include/linux/atomic.h:7,
from include/linux/tracepoint-defs.h:11,
from include/linux/preempt.h:13,
from include/linux/alloc_tag.h:11,
from include/linux/rhashtable-types.h:12,
from include/linux/ipc.h:7,
from include/uapi/linux/sem.h:5,
from include/linux/sem.h:5,
from include/linux/compat.h:14,
from kernel/compat.c:12:
include/linux/irqflags.h:201:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_enable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:201:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
>> include/linux/irqflags.h:201:1: warning: parameter names (without types) in function declaration
include/linux/irqflags.h:202:1: warning: data definition has no type or storage class
DECLARE_TRACEPOINT(irq_disable);
^~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:202:1: error: type defaults to 'int' in declaration of 'DECLARE_TRACEPOINT' [-Werror=implicit-int]
include/linux/irqflags.h:202:1: warning: parameter names (without types) in function declaration
In file included from include/linux/jump_label.h:78,
from include/linux/dynamic_debug.h:6,
from include/linux/printk.h:616,
from include/asm-generic/bug.h:22,
from arch/sparc/include/asm/bug.h:25,
from include/linux/bug.h:5,
from include/linux/alloc_tag.h:8,
from include/linux/rhashtable-types.h:12,
from include/linux/ipc.h:7,
from include/uapi/linux/sem.h:5,
from include/linux/sem.h:5,
from include/linux/compat.h:14,
from kernel/compat.c:12:
include/linux/irqflags.h: In function 'class_irq_destructor':
include/linux/irqflags.h:206:7: error: implicit declaration of function 'tracepoint_enabled'; did you mean 'static_key_enabled'? [-Werror=implicit-function-declaration]
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'ctl_table'?
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h:206:26: note: each undeclared identifier is reported only once for each function it appears in
if (tracepoint_enabled(irq_enable)) \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:47: note: in expansion of macro 'local_irq_enable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irq_constructor':
include/linux/irqflags.h:215:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:274:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:274:26: note: in expansion of macro 'local_irq_disable'
DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_destructor':
include/linux/irqflags.h:230:26: error: 'irq_enable' undeclared (first use in this function); did you mean 'ctl_table'?
if (tracepoint_enabled(irq_enable) && \
^~~~~~~~~~
include/linux/cleanup.h:385:18: note: in definition of macro '__DEFINE_UNLOCK_GUARD'
if (_T->lock) { _unlock; } \
^~~~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:277:7: note: in expansion of macro 'local_irq_restore'
local_irq_restore(_T->flags),
^~~~~~~~~~~~~~~~~
include/linux/irqflags.h: In function 'class_irqsave_constructor':
include/linux/irqflags.h:223:26: error: 'irq_disable' undeclared (first use in this function); did you mean 'irqs_disabled'?
if (tracepoint_enabled(irq_disable) && \
^~~~~~~~~~~
include/linux/cleanup.h:403:2: note: in definition of macro '__DEFINE_LOCK_GUARD_0'
_lock; \
^~~~~
include/linux/irqflags.h:275:1: note: in expansion of macro 'DEFINE_LOCK_GUARD_0'
DEFINE_LOCK_GUARD_0(irqsave,
^~~~~~~~~~~~~~~~~~~
include/linux/irqflags.h:276:7: note: in expansion of macro 'local_irq_save'
local_irq_save(_T->flags),
^~~~~~~~~~~~~~
In file included from include/linux/dynamic_debug.h:6,
from include/linux/printk.h:616,
from include/asm-generic/bug.h:22,
from arch/sparc/include/asm/bug.h:25,
from include/linux/bug.h:5,
from include/linux/alloc_tag.h:8,
..
vim +201 include/linux/irqflags.h
00b0ed2d4997af Peter Zijlstra 2020-08-12 200
563d10fd41452f Wander Lairson Costa 2025-06-26 @201 DECLARE_TRACEPOINT(irq_enable);
563d10fd41452f Wander Lairson Costa 2025-06-26 202 DECLARE_TRACEPOINT(irq_disable);
563d10fd41452f Wander Lairson Costa 2025-06-26 203
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Hi Wander,
kernel test robot noticed the following build errors:
[auto build test ERROR on trace/for-next]
[also build test ERROR on tip/sched/core linus/master v6.16-rc3 next-20250627]
[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/Wander-Lairson-Costa/trace-preemptirq-reduce-overhead-of-irq_enable-disable-tracepoints/20250626-222438
base: https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link: https://lore.kernel.org/r/20250626142017.26372-3-wander%40redhat.com
patch subject: [PATCH 2/2] tracing/preemptirq: Optimize preempt_disable/enable() tracepoint overhead
config: powerpc-randconfig-002-20250628 (https://download.01.org/0day-ci/archive/20250628/202506280524.R4BJehMT-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250628/202506280524.R4BJehMT-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/202506280524.R4BJehMT-lkp@intel.com/
All errors (new ones prefixed by >>):
In file included from arch/powerpc/kernel/asm-offsets.c:12:
In file included from include/linux/compat.h:14:
In file included from include/linux/sem.h:5:
In file included from include/uapi/linux/sem.h:5:
In file included from include/linux/ipc.h:7:
In file included from include/linux/rhashtable-types.h:12:
In file included from include/linux/alloc_tag.h:11:
In file included from include/linux/preempt.h:13:
In file included from include/linux/tracepoint-defs.h:11:
In file included from include/linux/atomic.h:7:
In file included from arch/powerpc/include/asm/atomic.h:11:
In file included from arch/powerpc/include/asm/cmpxchg.h:755:
In file included from include/asm-generic/cmpxchg-local.h:6:
>> include/linux/irqflags.h:201:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
201 | DECLARE_TRACEPOINT(irq_enable);
| ^
| int
>> include/linux/irqflags.h:201:20: error: a parameter list without types is only allowed in a function definition
201 | DECLARE_TRACEPOINT(irq_enable);
| ^
include/linux/irqflags.h:202:1: error: type specifier missing, defaults to 'int'; ISO C99 and later do not support implicit int [-Wimplicit-int]
202 | DECLARE_TRACEPOINT(irq_disable);
| ^
| int
include/linux/irqflags.h:202:20: error: a parameter list without types is only allowed in a function definition
202 | DECLARE_TRACEPOINT(irq_disable);
| ^
>> include/linux/irqflags.h:274:47: error: call to undeclared function 'tracepoint_enabled'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
274 | DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
| ^
include/linux/irqflags.h:206:7: note: expanded from macro 'local_irq_enable'
206 | if (tracepoint_enabled(irq_enable)) \
| ^
>> include/linux/irqflags.h:274:47: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:206:26: note: expanded from macro 'local_irq_enable'
206 | if (tracepoint_enabled(irq_enable)) \
| ^
>> include/linux/irqflags.h:274:47: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:206:26: note: expanded from macro 'local_irq_enable'
206 | if (tracepoint_enabled(irq_enable)) \
| ^
>> include/linux/irqflags.h:274:47: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:206:26: note: expanded from macro 'local_irq_enable'
206 | if (tracepoint_enabled(irq_enable)) \
| ^
include/linux/irqflags.h:274:26: error: call to undeclared function 'tracepoint_enabled'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
274 | DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
| ^
include/linux/irqflags.h:215:7: note: expanded from macro 'local_irq_disable'
215 | if (tracepoint_enabled(irq_disable) && \
| ^
>> include/linux/irqflags.h:274:26: error: use of undeclared identifier 'irq_disable'; did you mean 'was_disabled'?
include/linux/irqflags.h:215:26: note: expanded from macro 'local_irq_disable'
215 | if (tracepoint_enabled(irq_disable) && \
| ^
include/linux/irqflags.h:274:26: note: 'was_disabled' declared here
include/linux/irqflags.h:213:8: note: expanded from macro 'local_irq_disable'
213 | bool was_disabled = raw_irqs_disabled();\
| ^
>> include/linux/irqflags.h:274:26: error: use of undeclared identifier 'irq_disable'; did you mean 'was_disabled'?
274 | DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
| ^
include/linux/irqflags.h:215:26: note: expanded from macro 'local_irq_disable'
215 | if (tracepoint_enabled(irq_disable) && \
| ^
include/linux/irqflags.h:274:26: note: 'was_disabled' declared here
include/linux/irqflags.h:213:8: note: expanded from macro 'local_irq_disable'
213 | bool was_disabled = raw_irqs_disabled();\
| ^
>> include/linux/irqflags.h:274:26: error: use of undeclared identifier 'irq_disable'; did you mean 'was_disabled'?
274 | DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
| ^
include/linux/irqflags.h:215:26: note: expanded from macro 'local_irq_disable'
215 | if (tracepoint_enabled(irq_disable) && \
| ^
include/linux/irqflags.h:274:26: note: 'was_disabled' declared here
include/linux/irqflags.h:213:8: note: expanded from macro 'local_irq_disable'
213 | bool was_disabled = raw_irqs_disabled();\
| ^
include/linux/irqflags.h:277:7: error: call to undeclared function 'tracepoint_enabled'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
277 | local_irq_restore(_T->flags),
| ^
include/linux/irqflags.h:230:7: note: expanded from macro 'local_irq_restore'
230 | if (tracepoint_enabled(irq_enable) && \
| ^
include/linux/irqflags.h:277:7: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:230:26: note: expanded from macro 'local_irq_restore'
230 | if (tracepoint_enabled(irq_enable) && \
| ^
include/linux/irqflags.h:277:7: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:230:26: note: expanded from macro 'local_irq_restore'
230 | if (tracepoint_enabled(irq_enable) && \
| ^
include/linux/irqflags.h:277:7: error: use of undeclared identifier 'irq_enable'
include/linux/irqflags.h:230:26: note: expanded from macro 'local_irq_restore'
230 | if (tracepoint_enabled(irq_enable) && \
| ^
include/linux/irqflags.h:276:7: error: call to undeclared function 'tracepoint_enabled'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
276 | local_irq_save(_T->flags),
| ^
include/linux/irqflags.h:223:7: note: expanded from macro 'local_irq_save'
223 | if (tracepoint_enabled(irq_disable) && \
| ^
include/linux/irqflags.h:276:7: error: use of undeclared identifier 'irq_disable'
include/linux/irqflags.h:223:26: note: expanded from macro 'local_irq_save'
223 | if (tracepoint_enabled(irq_disable) && \
| ^
include/linux/irqflags.h:276:7: error: use of undeclared identifier 'irq_disable'
include/linux/irqflags.h:223:26: note: expanded from macro 'local_irq_save'
223 | if (tracepoint_enabled(irq_disable) && \
| ^
fatal error: too many errors emitted, stopping now [-ferror-limit=]
20 errors generated.
make[3]: *** [scripts/Makefile.build:98: arch/powerpc/kernel/asm-offsets.s] Error 1 shuffle=1905180499
make[3]: Target 'prepare' not remade because of errors.
make[2]: *** [Makefile:1274: prepare0] Error 2 shuffle=1905180499
make[2]: Target 'prepare' not remade because of errors.
make[1]: *** [Makefile:248: __sub-make] Error 2 shuffle=1905180499
make[1]: Target 'prepare' not remade because of errors.
make: *** [Makefile:248: __sub-make] Error 2 shuffle=1905180499
make: Target 'prepare' not remade because of errors.
vim +/tracepoint_enabled +274 include/linux/irqflags.h
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 200
563d10fd41452f8 Wander Lairson Costa 2025-06-26 @201 DECLARE_TRACEPOINT(irq_enable);
563d10fd41452f8 Wander Lairson Costa 2025-06-26 @202 DECLARE_TRACEPOINT(irq_disable);
563d10fd41452f8 Wander Lairson Costa 2025-06-26 203
de30a2b355ea853 Ingo Molnar 2006-07-03 204 #define local_irq_enable() \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 205 do { \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 @206 if (tracepoint_enabled(irq_enable)) \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 207 trace_hardirqs_on(); \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 208 raw_local_irq_enable(); \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 209 } while (0)
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 210
de30a2b355ea853 Ingo Molnar 2006-07-03 211 #define local_irq_disable() \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 212 do { \
044d0d6de9f5019 Nicholas Piggin 2020-07-23 213 bool was_disabled = raw_irqs_disabled();\
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 214 raw_local_irq_disable(); \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 215 if (tracepoint_enabled(irq_disable) && \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 216 !was_disabled) \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 217 trace_hardirqs_off(); \
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 218 } while (0)
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 219
de30a2b355ea853 Ingo Molnar 2006-07-03 220 #define local_irq_save(flags) \
3f307891ce0e7b0 Steven Rostedt 2008-07-25 221 do { \
3f307891ce0e7b0 Steven Rostedt 2008-07-25 222 raw_local_irq_save(flags); \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 223 if (tracepoint_enabled(irq_disable) && \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 224 !raw_irqs_disabled_flags(flags)) \
3f307891ce0e7b0 Steven Rostedt 2008-07-25 225 trace_hardirqs_off(); \
3f307891ce0e7b0 Steven Rostedt 2008-07-25 226 } while (0)
3f307891ce0e7b0 Steven Rostedt 2008-07-25 227
de30a2b355ea853 Ingo Molnar 2006-07-03 228 #define local_irq_restore(flags) \
de30a2b355ea853 Ingo Molnar 2006-07-03 229 do { \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 230 if (tracepoint_enabled(irq_enable) && \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 231 !raw_irqs_disabled_flags(flags)) \
de30a2b355ea853 Ingo Molnar 2006-07-03 232 trace_hardirqs_on(); \
de30a2b355ea853 Ingo Molnar 2006-07-03 233 raw_local_irq_restore(flags); \
de30a2b355ea853 Ingo Molnar 2006-07-03 234 } while (0)
de30a2b355ea853 Ingo Molnar 2006-07-03 235
df9ee29270c11db David Howells 2010-10-07 236 #define safe_halt() \
df9ee29270c11db David Howells 2010-10-07 237 do { \
563d10fd41452f8 Wander Lairson Costa 2025-06-26 238 if (tracepoint_enabled(irq_enable)) \
df9ee29270c11db David Howells 2010-10-07 239 trace_hardirqs_on(); \
df9ee29270c11db David Howells 2010-10-07 240 raw_safe_halt(); \
df9ee29270c11db David Howells 2010-10-07 241 } while (0)
df9ee29270c11db David Howells 2010-10-07 242
df9ee29270c11db David Howells 2010-10-07 243
db2dcb4f91d5fec Jan Beulich 2015-01-20 244 #else /* !CONFIG_TRACE_IRQFLAGS */
df9ee29270c11db David Howells 2010-10-07 245
df9ee29270c11db David Howells 2010-10-07 246 #define local_irq_enable() do { raw_local_irq_enable(); } while (0)
df9ee29270c11db David Howells 2010-10-07 247 #define local_irq_disable() do { raw_local_irq_disable(); } while (0)
00b0ed2d4997af6 Peter Zijlstra 2020-08-12 248 #define local_irq_save(flags) do { raw_local_irq_save(flags); } while (0)
df9ee29270c11db David Howells 2010-10-07 249 #define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0)
df9ee29270c11db David Howells 2010-10-07 250 #define safe_halt() do { raw_safe_halt(); } while (0)
df9ee29270c11db David Howells 2010-10-07 251
db2dcb4f91d5fec Jan Beulich 2015-01-20 252 #endif /* CONFIG_TRACE_IRQFLAGS */
db2dcb4f91d5fec Jan Beulich 2015-01-20 253
db2dcb4f91d5fec Jan Beulich 2015-01-20 254 #define local_save_flags(flags) raw_local_save_flags(flags)
db2dcb4f91d5fec Jan Beulich 2015-01-20 255
db2dcb4f91d5fec Jan Beulich 2015-01-20 256 /*
db2dcb4f91d5fec Jan Beulich 2015-01-20 257 * Some architectures don't define arch_irqs_disabled(), so even if either
db2dcb4f91d5fec Jan Beulich 2015-01-20 258 * definition would be fine we need to use different ones for the time being
db2dcb4f91d5fec Jan Beulich 2015-01-20 259 * to avoid build issues.
db2dcb4f91d5fec Jan Beulich 2015-01-20 260 */
db2dcb4f91d5fec Jan Beulich 2015-01-20 261 #ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT
db2dcb4f91d5fec Jan Beulich 2015-01-20 262 #define irqs_disabled() \
db2dcb4f91d5fec Jan Beulich 2015-01-20 263 ({ \
db2dcb4f91d5fec Jan Beulich 2015-01-20 264 unsigned long _flags; \
db2dcb4f91d5fec Jan Beulich 2015-01-20 265 raw_local_save_flags(_flags); \
db2dcb4f91d5fec Jan Beulich 2015-01-20 266 raw_irqs_disabled_flags(_flags); \
db2dcb4f91d5fec Jan Beulich 2015-01-20 267 })
db2dcb4f91d5fec Jan Beulich 2015-01-20 268 #else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */
db2dcb4f91d5fec Jan Beulich 2015-01-20 269 #define irqs_disabled() raw_irqs_disabled()
40b1f4e5113eafc Michael Neuling 2009-10-22 270 #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */
de30a2b355ea853 Ingo Molnar 2006-07-03 271
db2dcb4f91d5fec Jan Beulich 2015-01-20 272 #define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags)
db2dcb4f91d5fec Jan Beulich 2015-01-20 273
54da6a0924311c7 Peter Zijlstra 2023-05-26 @274 DEFINE_LOCK_GUARD_0(irq, local_irq_disable(), local_irq_enable())
54da6a0924311c7 Peter Zijlstra 2023-05-26 275 DEFINE_LOCK_GUARD_0(irqsave,
54da6a0924311c7 Peter Zijlstra 2023-05-26 276 local_irq_save(_T->flags),
54da6a0924311c7 Peter Zijlstra 2023-05-26 277 local_irq_restore(_T->flags),
54da6a0924311c7 Peter Zijlstra 2023-05-26 278 unsigned long flags)
54da6a0924311c7 Peter Zijlstra 2023-05-26 279
--
0-DAY CI Kernel Test Service
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