qos_prof.h File Reference

Function-level profiling utilities. More...

#include "qos_debug.h"
#include <string.h>

Data Structures
struct	qos_profile_t
	Profile data that is allocated for each profiled function. More...
Defines
#define	QOS_PROF_MAX_COUNTS 128
	Maximum number of functions that can be profiled.
#define	QOS_PROF_NAME_SIZE 32
	Maximum length for the name of a profiled function, including string terminator.
#define	prof_vars
	This must be added in the var declaration section of a profiled function.
#define	prof_func()
	This must be the first statement of a profiled function.
#define	prof_return(args...) do { return args; } while (0)
#define	prof_end() do { } while (0)
#define	prof_call(args...) do { } while (0)
Functions
static void	prof_dump (void)
static qos_profile_t *	prof_register (const char *name)

Detailed Description

Function-level profiling utilities.

This file contains utilities for function-level profiling in either user-space or kernel-space. For each profiled function, the number of invocations and the total time spent inside function code (comprising called functions) is collected.

The prof_dump() function may be used to dump a report on the profiled functions. When in US, this info goes to stderr, when in KS, it goes to printk or klogger, depending on configuration.

In order to enable profiling, the QOS_PROFILE macro must be defined.

Use of this module prescribes to add, for each function to be profiled, the var declaration statement prof_vars, a call to prof_func() at the begin of the function, and exiting from the function through prof_return().

Furthermore, profiled code needs to be linked with qos_profile.c.

The typical sample use is as follows:

   void f(int x) {
     ...
     prof_vars;
     ...
     prof_func();
     ....
     if (! condition)
       prof_return();
     ...
     prof_return();
   }

   int g(int x) {
     ...
     prof_vars;
     ...
     prof_func();
     ....
     if (! condition)
       prof_return(-1);
     ...
     prof_return(0);
   }