diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst index 74d5bd801b1a..272464bb7c60 100644 --- a/Documentation/trace/ftrace.rst +++ b/Documentation/trace/ftrace.rst @@ -1033,9 +1033,13 @@ explains which is which. irqs-off: 'd' interrupts are disabled. '.' otherwise. need-resched: + - 'B' all, TIF_NEED_RESCHED, PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is set, - 'N' both TIF_NEED_RESCHED and PREEMPT_NEED_RESCHED is set, - 'n' only TIF_NEED_RESCHED is set, - 'p' only PREEMPT_NEED_RESCHED is set, + - 'L' both PREEMPT_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'b' both TIF_NEED_RESCHED and TIF_RESCHED_LAZY is set, + - 'l' only TIF_RESCHED_LAZY is set - '.' otherwise. hardirq/softirq: diff --git a/include/linux/rcupdate_trace.h b/include/linux/rcupdate_trace.h index eda493200663..e6c44eb428ab 100644 --- a/include/linux/rcupdate_trace.h +++ b/include/linux/rcupdate_trace.h @@ -10,6 +10,7 @@ #include #include +#include extern struct lockdep_map rcu_trace_lock_map; @@ -98,4 +99,8 @@ static inline void rcu_read_lock_trace(void) { BUG(); } static inline void rcu_read_unlock_trace(void) { BUG(); } #endif /* #ifdef CONFIG_TASKS_TRACE_RCU */ +DEFINE_LOCK_GUARD_0(rcu_tasks_trace, + rcu_read_lock_trace(), + rcu_read_unlock_trace()) + #endif /* __LINUX_RCUPDATE_TRACE_H */ diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 016b29a56c87..2a5df5b62cfc 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -184,6 +184,7 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status); enum trace_flag_type { TRACE_FLAG_IRQS_OFF = 0x01, + TRACE_FLAG_NEED_RESCHED_LAZY = 0x02, TRACE_FLAG_NEED_RESCHED = 0x04, TRACE_FLAG_HARDIRQ = 0x08, TRACE_FLAG_SOFTIRQ = 0x10, diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 6073a8c7e38c..76d9055b2cff 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -209,36 +209,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #define __DO_TRACE_CALL(name, args) __traceiter_##name(NULL, args) #endif /* CONFIG_HAVE_STATIC_CALL */ -/* - * it_func[0] is never NULL because there is at least one element in the array - * when the array itself is non NULL. - * - * With @syscall=0, the tracepoint callback array dereference is - * protected by disabling preemption. - * With @syscall=1, the tracepoint callback array dereference is - * protected by Tasks Trace RCU, which allows probes to handle page - * faults. - */ -#define __DO_TRACE(name, args, cond, syscall) \ - do { \ - int __maybe_unused __idx = 0; \ - \ - if (!(cond)) \ - return; \ - \ - if (syscall) \ - rcu_read_lock_trace(); \ - else \ - preempt_disable_notrace(); \ - \ - __DO_TRACE_CALL(name, TP_ARGS(args)); \ - \ - if (syscall) \ - rcu_read_unlock_trace(); \ - else \ - preempt_enable_notrace(); \ - } while (0) - /* * Declare an exported function that Rust code can call to trigger this * tracepoint. This function does not include the static branch; that is done @@ -262,7 +232,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) * site if it is not watching, as it will need to be active when the * tracepoint is enabled. */ -#define __DECLARE_TRACE_COMMON(name, proto, args, cond, data_proto) \ +#define __DECLARE_TRACE_COMMON(name, proto, args, data_proto) \ extern int __traceiter_##name(data_proto); \ DECLARE_STATIC_CALL(tp_func_##name, __traceiter_##name); \ extern struct tracepoint __tracepoint_##name; \ @@ -297,41 +267,43 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) } #define __DECLARE_TRACE(name, proto, args, cond, data_proto) \ - __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \ + __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \ static inline void __rust_do_trace_##name(proto) \ { \ - __DO_TRACE(name, \ - TP_ARGS(args), \ - TP_CONDITION(cond), 0); \ + if (cond) { \ + guard(preempt_notrace)(); \ + __DO_TRACE_CALL(name, TP_ARGS(args)); \ + } \ } \ static inline void trace_##name(proto) \ { \ - if (static_branch_unlikely(&__tracepoint_##name.key)) \ - __DO_TRACE(name, \ - TP_ARGS(args), \ - TP_CONDITION(cond), 0); \ + if (static_branch_unlikely(&__tracepoint_##name.key)) { \ + if (cond) { \ + guard(preempt_notrace)(); \ + __DO_TRACE_CALL(name, TP_ARGS(args)); \ + } \ + } \ if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \ WARN_ONCE(!rcu_is_watching(), \ "RCU not watching for tracepoint"); \ } \ } -#define __DECLARE_TRACE_SYSCALL(name, proto, args, cond, data_proto) \ - __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), cond, PARAMS(data_proto)) \ +#define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto) \ + __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) \ static inline void __rust_do_trace_##name(proto) \ { \ - __DO_TRACE(name, \ - TP_ARGS(args), \ - TP_CONDITION(cond), 1); \ + guard(rcu_tasks_trace)(); \ + __DO_TRACE_CALL(name, TP_ARGS(args)); \ } \ static inline void trace_##name(proto) \ { \ might_fault(); \ - if (static_branch_unlikely(&__tracepoint_##name.key)) \ - __DO_TRACE(name, \ - TP_ARGS(args), \ - TP_CONDITION(cond), 1); \ - if (IS_ENABLED(CONFIG_LOCKDEP) && (cond)) { \ + if (static_branch_unlikely(&__tracepoint_##name.key)) { \ + guard(rcu_tasks_trace)(); \ + __DO_TRACE_CALL(name, TP_ARGS(args)); \ + } \ + if (IS_ENABLED(CONFIG_LOCKDEP)) { \ WARN_ONCE(!rcu_is_watching(), \ "RCU not watching for tracepoint"); \ } \ @@ -341,6 +313,9 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) * We have no guarantee that gcc and the linker won't up-align the tracepoint * structures, so we create an array of pointers that will be used for iteration * on the tracepoints. + * + * it_func[0] is never NULL because there is at least one element in the array + * when the array itself is non NULL. */ #define __DEFINE_TRACE_EXT(_name, _ext, proto, args) \ static const char __tpstrtab_##_name[] \ @@ -412,7 +387,7 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #else /* !TRACEPOINTS_ENABLED */ -#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \ +#define __DECLARE_TRACE_COMMON(name, proto, args, data_proto) \ static inline void trace_##name(proto) \ { } \ static inline int \ @@ -436,7 +411,11 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) return false; \ } -#define __DECLARE_TRACE_SYSCALL __DECLARE_TRACE +#define __DECLARE_TRACE(name, proto, args, cond, data_proto) \ + __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) + +#define __DECLARE_TRACE_SYSCALL(name, proto, args, data_proto) \ + __DECLARE_TRACE_COMMON(name, PARAMS(proto), PARAMS(args), PARAMS(data_proto)) #define DEFINE_TRACE_FN(name, reg, unreg, proto, args) #define DEFINE_TRACE_SYSCALL(name, reg, unreg, proto, args) @@ -502,7 +481,6 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #define DECLARE_TRACE_SYSCALL(name, proto, args) \ __DECLARE_TRACE_SYSCALL(name, PARAMS(proto), PARAMS(args), \ - cpu_online(raw_smp_processor_id()), \ PARAMS(void *__data, proto)) #define TRACE_EVENT_FLAGS(event, flag) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3ef047ed9705..be62f0ea1814 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2552,6 +2552,8 @@ unsigned int tracing_gen_ctx_irq_test(unsigned int irqs_status) trace_flags |= TRACE_FLAG_NEED_RESCHED; if (test_preempt_need_resched()) trace_flags |= TRACE_FLAG_PREEMPT_RESCHED; + if (IS_ENABLED(CONFIG_ARCH_HAS_PREEMPT_LAZY) && tif_test_bit(TIF_NEED_RESCHED_LAZY)) + trace_flags |= TRACE_FLAG_NEED_RESCHED_LAZY; return (trace_flags << 16) | (min_t(unsigned int, pc & 0xff, 0xf)) | (min_t(unsigned int, migration_disable_value(), 0xf)) << 4; } diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index e08aee34ef63..da748b7cbc4d 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -462,17 +462,29 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry) bh_off ? 'b' : '.'; - switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | + switch (entry->flags & (TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED)) { + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED: + need_resched = 'B'; + break; case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_PREEMPT_RESCHED: need_resched = 'N'; break; + case TRACE_FLAG_NEED_RESCHED_LAZY | TRACE_FLAG_PREEMPT_RESCHED: + need_resched = 'L'; + break; + case TRACE_FLAG_NEED_RESCHED | TRACE_FLAG_NEED_RESCHED_LAZY: + need_resched = 'b'; + break; case TRACE_FLAG_NEED_RESCHED: need_resched = 'n'; break; case TRACE_FLAG_PREEMPT_RESCHED: need_resched = 'p'; break; + case TRACE_FLAG_NEED_RESCHED_LAZY: + need_resched = 'l'; + break; default: need_resched = '.'; break;