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Diffstat (limited to 'src/include/ipxe/profile.h')
-rw-r--r-- | src/include/ipxe/profile.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/src/include/ipxe/profile.h b/src/include/ipxe/profile.h new file mode 100644 index 0000000..60dd53a --- /dev/null +++ b/src/include/ipxe/profile.h @@ -0,0 +1,80 @@ +#ifndef _IPXE_PROFILE_H +#define _IPXE_PROFILE_H + +/** @file + * + * Profiling + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include <stdint.h> + +/** + * A data structure for storing profiling information + */ +union profiler { + /** Timestamp (in CPU-specific "ticks") */ + uint64_t timestamp; + /** Registers returned by rdtsc. + * + * This part should really be architecture-specific code. + */ + struct { + uint32_t eax; + uint32_t edx; + } rdtsc; +}; + +/** + * Static per-object profiler, for use with simple_profile() + */ +static union profiler simple_profiler; + +/** + * Perform profiling + * + * @v profiler Profiler data structure + * @ret delta Elapsed ticks since last call to profile(). + * + * Call profile() both before and after the code you wish to measure. + * The "after" call will return the measurement. For example: + * + * @code + * + * profile ( &profiler ); + * ... do something here ... + * printf ( "It took %ld ticks to execute\n", profile ( &profiler ) ); + * + * @endcode + */ +static inline __attribute__ (( always_inline )) unsigned long +profile ( union profiler *profiler ) { + uint64_t last_timestamp = profiler->timestamp; + + __asm__ __volatile__ ( "rdtsc" : + "=a" ( profiler->rdtsc.eax ), + "=d" ( profiler->rdtsc.edx ) ); + return ( profiler->timestamp - last_timestamp ); +} + +/** + * Perform profiling + * + * @ret delta Elapsed ticks since last call to profile(). + * + * When you only need one profiler, you can avoid the hassle of + * creating your own @c profiler data structure by using + * simple_profile() instead. + * + * simple_profile() is equivalent to profile(&simple_profiler), where + * @c simple_profiler is a @c profiler data structure that is static + * to each object which includes @c profile.h. + */ +static inline __attribute__ (( always_inline )) unsigned long +simple_profile ( void ) { + return profile ( &simple_profiler ); +} + +#endif /* _IPXE_PROFILE_H */ |