From 163363455b42a1cf833742177149d1352dfe673e Mon Sep 17 00:00:00 2001 From: Yafang Shao Date: Tue, 26 Mar 2019 20:13:09 +0800 Subject: tracing: introduce TRACE_EVENT_NOP() Sometimes we want to define a tracepoint as a do-nothing function. So I introduce TRACE_EVENT_NOP, DECLARE_EVENT_CLASS_NOP and DEFINE_EVENT_NOP for this kind of usage. Link: http://lkml.kernel.org/r/1553602391-11926-2-git-send-email-laoar.shao@gmail.com Signed-off-by: Yafang Shao Signed-off-by: Steven Rostedt (VMware) --- include/linux/tracepoint.h | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'include/linux') diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 9c3186578ce0..86b019aa2839 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -548,4 +548,19 @@ static inline struct tracepoint *tracepoint_ptr_deref(tracepoint_ptr_t *p) #define TRACE_EVENT_PERF_PERM(event, expr...) +#define DECLARE_EVENT_NOP(name, proto, args) \ + static inline void trace_##name(proto) \ + { } \ + static inline bool trace_##name##_enabled(void) \ + { \ + return false; \ + } + +#define TRACE_EVENT_NOP(name, proto, args, struct, assign, print) \ + DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args)) + +#define DECLARE_EVENT_CLASS_NOP(name, proto, args, tstruct, assign, print) +#define DEFINE_EVENT_NOP(template, name, proto, args) \ + DECLARE_EVENT_NOP(name, PARAMS(proto), PARAMS(args)) + #endif /* ifdef TRACE_EVENT (see note above) */ -- cgit v1.2.3-71-gd317 From e8025bab7bfbd48d262c01c26c15a9d465fbb083 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 24 Apr 2019 12:34:46 -0400 Subject: function_graph: Place ftrace_graph_entry_stub() prototype in include/linux/ftrace.h ftrace_graph_entry_stub() is defined in generic code, its prototype should be in the generic header and not defined throughout architecture specific code in order to use it. Cc: Greentime Hu Cc: Vincent Chen Cc: "James E.J. Bottomley" Cc: Helge Deller Cc: linux-parisc@vger.kernel.org Signed-off-by: Steven Rostedt (VMware) --- arch/nds32/kernel/ftrace.c | 1 - arch/parisc/kernel/ftrace.c | 1 - include/linux/ftrace.h | 2 ++ 3 files changed, 2 insertions(+), 2 deletions(-) (limited to 'include/linux') diff --git a/arch/nds32/kernel/ftrace.c b/arch/nds32/kernel/ftrace.c index 8a41372551ff..fd2a54b8cd57 100644 --- a/arch/nds32/kernel/ftrace.c +++ b/arch/nds32/kernel/ftrace.c @@ -7,7 +7,6 @@ #ifndef CONFIG_DYNAMIC_FTRACE extern void (*ftrace_trace_function)(unsigned long, unsigned long, struct ftrace_ops*, struct pt_regs*); -extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); extern void ftrace_graph_caller(void); noinline void __naked ftrace_stub(unsigned long ip, unsigned long parent_ip, diff --git a/arch/parisc/kernel/ftrace.c b/arch/parisc/kernel/ftrace.c index e46a4157a894..a28f915993b1 100644 --- a/arch/parisc/kernel/ftrace.c +++ b/arch/parisc/kernel/ftrace.c @@ -51,7 +51,6 @@ void notrace __hot ftrace_function_trampoline(unsigned long parent, unsigned long org_sp_gr3) { extern ftrace_func_t ftrace_trace_function; /* depends on CONFIG_DYNAMIC_FTRACE */ - extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); if (ftrace_trace_function != ftrace_stub) { /* struct ftrace_ops *op, struct pt_regs *regs); */ diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 730876187344..9b28fce436ca 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -751,6 +751,8 @@ struct ftrace_graph_ret { typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */ typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */ +extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace); + #ifdef CONFIG_FUNCTION_GRAPH_TRACER struct fgraph_ops { -- cgit v1.2.3-71-gd317 From a15fd609ad53a631a927c6680e8fb606f42a712b Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 20 Mar 2019 10:26:17 -0700 Subject: tracing: Simplify "if" macro code Peter Zijlstra noticed that with CONFIG_PROFILE_ALL_BRANCHES, the "if" macro converts the conditional to an array index. This can cause GCC to create horrible code. When there are nested ifs, the generated code uses register values to encode branching decisions. Josh Poimboeuf found that replacing the define "if" macro from using the condition as an array index and incrementing the branch statics with an if statement itself, reduced the asm complexity and shrinks the generated code quite a bit. But this can be simplified even further by replacing the internal if statement with a ternary operator. Link: https://lkml.kernel.org/r/20190307174802.46fmpysxyo35hh43@treble Link: http://lkml.kernel.org/r/CAHk-=wiALN3jRuzARpwThN62iKd476Xj-uom+YnLZ4=eqcz7xQ@mail.gmail.com Reported-by: Peter Zijlstra (Intel) Reported-by: Josh Poimboeuf Signed-off-by: Linus Torvalds Signed-off-by: Steven Rostedt (VMware) --- include/linux/compiler.h | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) (limited to 'include/linux') diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 445348facea9..8aaf7cd026b0 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -53,23 +53,24 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val, * "Define 'is'", Bill Clinton * "Define 'if'", Steven Rostedt */ -#define if(cond, ...) __trace_if( (cond , ## __VA_ARGS__) ) -#define __trace_if(cond) \ - if (__builtin_constant_p(!!(cond)) ? !!(cond) : \ - ({ \ - int ______r; \ - static struct ftrace_branch_data \ - __aligned(4) \ - __section("_ftrace_branch") \ - ______f = { \ - .func = __func__, \ - .file = __FILE__, \ - .line = __LINE__, \ - }; \ - ______r = !!(cond); \ - ______f.miss_hit[______r]++; \ - ______r; \ - })) +#define if(cond, ...) if ( __trace_if_var( !!(cond , ## __VA_ARGS__) ) ) + +#define __trace_if_var(cond) (__builtin_constant_p(cond) ? (cond) : __trace_if_value(cond)) + +#define __trace_if_value(cond) ({ \ + static struct ftrace_branch_data \ + __aligned(4) \ + __section("_ftrace_branch") \ + __if_trace = { \ + .func = __func__, \ + .file = __FILE__, \ + .line = __LINE__, \ + }; \ + (cond) ? \ + (__if_trace.miss_hit[1]++,1) : \ + (__if_trace.miss_hit[0]++,0); \ +}) + #endif /* CONFIG_PROFILE_ALL_BRANCHES */ #else -- cgit v1.2.3-71-gd317