From bd2a634d9e852b9b6100f9ae9c3c790b0ff91ce0 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 1 Dec 2015 17:00:58 -0800 Subject: tracepoints: Move struct tracepoint to new tracepoint-defs.h header Steven recommended open coding access to tracepoint->key to add trace points to headers. Unfortunately this is difficult for some headers (such as x86 asm/msr.h) because including tracepoint.h includes so many other headers that it causes include loops. The main problem is the include of linux/rcupdate.h, which pulls in a lot of other headers. The rcu header is only needed when actually defining trace points. Move the struct tracepoint into a separate tracepoint-defs.h header that can be included without pulling in all of RCU. Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Acked-by: Steven Rostedt Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Mike Galbraith Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Link: http://lkml.kernel.org/r/1449018060-1742-2-git-send-email-andi@firstfloor.org Signed-off-by: Ingo Molnar --- include/linux/tracepoint.h | 16 +--------------- 1 file changed, 1 insertion(+), 15 deletions(-) (limited to 'include/linux/tracepoint.h') diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 696a339c592c..f7c732bd5cbd 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -17,26 +17,12 @@ #include #include #include -#include +#include struct module; struct tracepoint; struct notifier_block; -struct tracepoint_func { - void *func; - void *data; - int prio; -}; - -struct tracepoint { - const char *name; /* Tracepoint name */ - struct static_key key; - void (*regfunc)(void); - void (*unregfunc)(void); - struct tracepoint_func __rcu *funcs; -}; - struct trace_enum_map { const char *system; const char *enum_string; -- cgit v1.2.3 From 7c9906ca5e582a773fff696975e312cef58a7386 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sat, 31 Oct 2015 00:59:01 -0700 Subject: rcu: Don't redundantly disable irqs in rcu_irq_{enter,exit}() This commit replaces a local_irq_save()/local_irq_restore() pair with a lockdep assertion that interrupts are already disabled. This should remove the corresponding overhead from the interrupt entry/exit fastpaths. This change was inspired by the fact that Iftekhar Ahmed's mutation testing showed that removing rcu_irq_enter()'s call to local_ird_restore() had no effect, which might indicate that interrupts were always enabled anyway. Signed-off-by: Paul E. McKenney --- include/linux/rcupdate.h | 4 ++-- include/linux/rcutiny.h | 8 ++++++++ include/linux/rcutree.h | 2 ++ include/linux/tracepoint.h | 4 ++-- kernel/rcu/tree.c | 32 ++++++++++++++++++++++++++------ 5 files changed, 40 insertions(+), 10 deletions(-) (limited to 'include/linux/tracepoint.h') diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a0189ba67fde..f2b667df1131 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -379,9 +379,9 @@ static inline void rcu_init_nohz(void) */ #define RCU_NONIDLE(a) \ do { \ - rcu_irq_enter(); \ + rcu_irq_enter_irqson(); \ do { a; } while (0); \ - rcu_irq_exit(); \ + rcu_irq_exit_irqson(); \ } while (0) /* diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 4c1aaf9cce7b..64809aea661c 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -181,6 +181,14 @@ static inline void rcu_irq_enter(void) { } +static inline void rcu_irq_exit_irqson(void) +{ +} + +static inline void rcu_irq_enter_irqson(void) +{ +} + static inline void rcu_irq_exit(void) { } diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index 9d3eda39bcd2..ad1eda9fa4da 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -97,6 +97,8 @@ void rcu_idle_enter(void); void rcu_idle_exit(void); void rcu_irq_enter(void); void rcu_irq_exit(void); +void rcu_irq_enter_irqson(void); +void rcu_irq_exit_irqson(void); void exit_rcu(void); diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 696a339c592c..7834a8a8bf1e 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -171,8 +171,8 @@ extern void syscall_unregfunc(void); TP_PROTO(data_proto), \ TP_ARGS(data_args), \ TP_CONDITION(cond), \ - rcu_irq_enter(), \ - rcu_irq_exit()); \ + rcu_irq_enter_irqson(), \ + rcu_irq_exit_irqson()); \ } #else #define __DECLARE_TRACE_RCU(name, proto, args, cond, data_proto, data_args) diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index d6863bceeb45..40940b0d0310 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -732,7 +732,7 @@ void rcu_user_enter(void) * * Exit from an interrupt handler, which might possibly result in entering * idle mode, in other words, leaving the mode in which read-side critical - * sections can occur. + * sections can occur. The caller must have disabled interrupts. * * This code assumes that the idle loop never does anything that might * result in unbalanced calls to irq_enter() and irq_exit(). If your @@ -745,11 +745,10 @@ void rcu_user_enter(void) */ void rcu_irq_exit(void) { - unsigned long flags; long long oldval; struct rcu_dynticks *rdtp; - local_irq_save(flags); + RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_exit() invoked with irqs enabled!!!"); rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting--; @@ -760,6 +759,17 @@ void rcu_irq_exit(void) else rcu_eqs_enter_common(oldval, true); rcu_sysidle_enter(1); +} + +/* + * Wrapper for rcu_irq_exit() where interrupts are enabled. + */ +void rcu_irq_exit_irqson(void) +{ + unsigned long flags; + + local_irq_save(flags); + rcu_irq_exit(); local_irq_restore(flags); } @@ -857,7 +867,7 @@ void rcu_user_exit(void) * * Enter an interrupt handler, which might possibly result in exiting * idle mode, in other words, entering the mode in which read-side critical - * sections can occur. + * sections can occur. The caller must have disabled interrupts. * * Note that the Linux kernel is fully capable of entering an interrupt * handler that it never exits, for example when doing upcalls to @@ -873,11 +883,10 @@ void rcu_user_exit(void) */ void rcu_irq_enter(void) { - unsigned long flags; struct rcu_dynticks *rdtp; long long oldval; - local_irq_save(flags); + RCU_LOCKDEP_WARN(!irqs_disabled(), "rcu_irq_enter() invoked with irqs enabled!!!"); rdtp = this_cpu_ptr(&rcu_dynticks); oldval = rdtp->dynticks_nesting; rdtp->dynticks_nesting++; @@ -888,6 +897,17 @@ void rcu_irq_enter(void) else rcu_eqs_exit_common(oldval, true); rcu_sysidle_exit(1); +} + +/* + * Wrapper for rcu_irq_enter() where interrupts are enabled. + */ +void rcu_irq_enter_irqson(void) +{ + unsigned long flags; + + local_irq_save(flags); + rcu_irq_enter(); local_irq_restore(flags); } -- cgit v1.2.3 From 2701121b8f4db4d69c327c0d8f8694ff2ce30ef7 Mon Sep 17 00:00:00 2001 From: Denis Kirjanov Date: Mon, 14 Dec 2015 23:18:05 +0300 Subject: tracing: Introduce TRACE_EVENT_FN_COND macro TRACE_EVENT_FN can't be used in some circumstances like invoking trace functions from offlined CPU due to RCU usage. This patch adds the TRACE_EVENT_FN_COND macro to make such trace points conditional. Link: http://lkml.kernel.org/r/1450124286-4822-1-git-send-email-kda@linux-powerpc.org Signed-off-by: Denis Kirjanov Signed-off-by: Steven Rostedt --- include/linux/tracepoint.h | 4 ++++ include/trace/define_trace.h | 6 ++++++ include/trace/trace_events.h | 6 ++++++ 3 files changed, 16 insertions(+) (limited to 'include/linux/tracepoint.h') diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 696a339c592c..45b3fcf7dd3c 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -493,6 +493,10 @@ extern void syscall_unregfunc(void); #define TRACE_EVENT_FN(name, proto, args, struct, \ assign, print, reg, unreg) \ DECLARE_TRACE(name, PARAMS(proto), PARAMS(args)) +#define TRACE_EVENT_FN_COND(name, proto, args, cond, struct, \ + assign, print, reg, unreg) \ + DECLARE_TRACE_CONDITION(name, PARAMS(proto), \ + PARAMS(args), PARAMS(cond)) #define TRACE_EVENT_CONDITION(name, proto, args, cond, \ struct, assign, print) \ DECLARE_TRACE_CONDITION(name, PARAMS(proto), \ diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h index 2d8639ea64d5..6e3945f64102 100644 --- a/include/trace/define_trace.h +++ b/include/trace/define_trace.h @@ -40,6 +40,11 @@ assign, print, reg, unreg) \ DEFINE_TRACE_FN(name, reg, unreg) +#undef TRACE_EVENT_FN_COND +#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \ + assign, print, reg, unreg) \ + DEFINE_TRACE_FN(name, reg, unreg) + #undef DEFINE_EVENT #define DEFINE_EVENT(template, name, proto, args) \ DEFINE_TRACE(name) @@ -93,6 +98,7 @@ #undef TRACE_EVENT #undef TRACE_EVENT_FN +#undef TRACE_EVENT_FN_COND #undef TRACE_EVENT_CONDITION #undef DECLARE_EVENT_CLASS #undef DEFINE_EVENT diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index de996cf61053..170c93bbdbb7 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -123,6 +123,12 @@ TRACE_MAKE_SYSTEM_STR(); TRACE_EVENT(name, PARAMS(proto), PARAMS(args), \ PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \ +#undef TRACE_EVENT_FN_COND +#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \ + assign, print, reg, unreg) \ + TRACE_EVENT_CONDITION(name, PARAMS(proto), PARAMS(args), PARAMS(cond), \ + PARAMS(tstruct), PARAMS(assign), PARAMS(print)) \ + #undef TRACE_EVENT_FLAGS #define TRACE_EVENT_FLAGS(name, value) \ __TRACE_EVENT_FLAGS(name, value) -- cgit v1.2.3