Commit 79b17ea7 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing updates from Steven Rostedt:
 "This release has no new tracing features, just clean ups, minor fixes
  and small optimizations"

* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits)
  tracing: Remove outdated ring buffer comment
  tracing/probes: Fix a warning message to show correct maximum length
  tracing: Fix return value check in trace_benchmark_reg()
  tracing: Use modern function declaration
  jump_label: Reduce the size of struct static_key
  tracing/probe: Show subsystem name in messages
  tracing/hwlat: Update old comment about migration
  timers: Make flags output in the timer_start tracepoint useful
  tracing: Have traceprobe_probes_write() not access userspace unnecessarily
  tracing: Have COMM event filter key be treated as a string
  ftrace: Have set_graph_function handle multiple functions in one write
  ftrace: Do not hold references of ftrace_graph_{notrace_}hash out of graph_lock
  tracing: Reset parser->buffer to allow multiple "puts"
  ftrace: Have set_graph_functions handle write with RDWR
  ftrace: Reset fgd->hash in ftrace_graph_write()
  ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY
  ftrace: Create a slight optimization on searching the ftrace_hash
  tracing: Add ftrace_hash_key() helper function
  ftrace: Convert graph filter to use hash tables
  ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip
  ...
parents e5d56efc 67d04bb2

Documentation/static-keys.txt

+3 −1
Original line number Diff line number Diff line
@@ -155,7 +155,9 @@ or: 


There are a few functions and macros that architectures must implement in order

to take advantage of this optimization. If there is no architecture support, we

simply fall back to a traditional, load, test, and jump sequence.

simply fall back to a traditional, load, test, and jump sequence. Also, the

struct jump_entry table must be at least 4-byte aligned because the

static_key->entry field makes use of the two least significant bits.



* select HAVE_ARCH_JUMP_LABEL, see: arch/x86/Kconfig

include/linux/compiler.h

+17 −10
Original line number Diff line number Diff line
@@ -105,29 +105,36 @@ struct ftrace_branch_data { 
	};

};



struct ftrace_likely_data {

	struct ftrace_branch_data	data;

	unsigned long			constant;

};



/*

 * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code

 * to disable branch tracing on a per file basis.

 */

#if defined(CONFIG_TRACE_BRANCH_PROFILING) \

    && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)

void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);

void ftrace_likely_update(struct ftrace_likely_data *f, int val,

			  int expect, int is_constant);



#define likely_notrace(x)	__builtin_expect(!!(x), 1)

#define unlikely_notrace(x)	__builtin_expect(!!(x), 0)



#define __branch_check__(x, expect) ({					\

#define __branch_check__(x, expect, is_constant) ({			\

			int ______r;					\

			static struct ftrace_branch_data		\

			static struct ftrace_likely_data		\

				__attribute__((__aligned__(4)))		\

				__attribute__((section("_ftrace_annotated_branch"))) \

				______f = {				\

				.func = __func__,			\

				.file = __FILE__,			\

				.line = __LINE__,			\

				.data.func = __func__,			\

				.data.file = __FILE__,			\

				.data.line = __LINE__,			\

			};						\

			______r = likely_notrace(x);			\

			ftrace_likely_update(&______f, ______r, expect); \

			______r = __builtin_expect(!!(x), expect);	\

			ftrace_likely_update(&______f, ______r,		\

					     expect, is_constant);	\

			______r;					\

		})
@@ -137,10 +144,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect); 
 * written by Daniel Walker.

 */

# ifndef likely

#  define likely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))

#  define likely(x)	(__branch_check__(x, 1, __builtin_constant_p(x)))

# endif

# ifndef unlikely

#  define unlikely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))

#  define unlikely(x)	(__branch_check__(x, 0, __builtin_constant_p(x)))

# endif



#ifdef CONFIG_PROFILE_ALL_BRANCHES

include/linux/jump_label.h

+15 −8
Original line number Diff line number Diff line
@@ -89,11 +89,17 @@ extern bool static_key_initialized; 


struct static_key {

	atomic_t enabled;

/* Set lsb bit to 1 if branch is default true, 0 ot */

/*

 * bit 0 => 1 if key is initially true

 *	    0 if initially false

 * bit 1 => 1 if points to struct static_key_mod

 *	    0 if points to struct jump_entry

 */

	union {

		unsigned long type;

		struct jump_entry *entries;

#ifdef CONFIG_MODULES

		struct static_key_mod *next;

#endif

	};

};



#else
@@ -120,7 +126,8 @@ struct module; 


#define JUMP_TYPE_FALSE		0UL

#define JUMP_TYPE_TRUE		1UL

#define JUMP_TYPE_MASK	1UL

#define JUMP_TYPE_LINKED	2UL

#define JUMP_TYPE_MASK		3UL



static __always_inline bool static_key_false(struct static_key *key)

{

include/linux/timer.h

+2 −0
Original line number Diff line number Diff line
@@ -61,6 +61,8 @@ struct timer_list { 
#define TIMER_ARRAYSHIFT	22

#define TIMER_ARRAYMASK		0xFFC00000



#define TIMER_TRACE_FLAGMASK	(TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)



#define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \

		.entry = { .next = TIMER_ENTRY_STATIC },	\

		.function = (_function),			\

include/trace/events/timer.h

+12 −2
Original line number Diff line number Diff line
@@ -36,6 +36,13 @@ DEFINE_EVENT(timer_class, timer_init, 
	TP_ARGS(timer)

);



#define decode_timer_flags(flags)			\

	__print_flags(flags, "|",			\

		{  TIMER_MIGRATING,	"M" },		\

		{  TIMER_DEFERRABLE,	"D" },		\

		{  TIMER_PINNED,	"P" },		\

		{  TIMER_IRQSAFE,	"I" })



/**

 * timer_start - called when the timer is started

 * @timer:	pointer to struct timer_list
@@ -65,9 +72,12 @@ TRACE_EVENT(timer_start, 
		__entry->flags		= flags;

	),



	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] flags=0x%08x",

	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] cpu=%u idx=%u flags=%s",

		  __entry->timer, __entry->function, __entry->expires,

		  (long)__entry->expires - __entry->now, __entry->flags)

		  (long)__entry->expires - __entry->now,

		  __entry->flags & TIMER_CPUMASK,

		  __entry->flags >> TIMER_ARRAYSHIFT,

		  decode_timer_flags(__entry->flags & TIMER_TRACE_FLAGMASK))

);



/**

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