sysadmin/ipxe
1
0
Fork 0
mirror of https://github.com/ipxe/ipxe synced 2025-12-22 04:50:25 +03:00
Code Issues Packages Projects Releases Wiki Activity

[fnrec] Enhance function recording

Browse Source 
Enhance the information collected by the function recorder to include
the call site and entry/exit counts.  This allows fnrec.pl to produce
a call tree such as:

    step (from core/getkey.c:46 = 0x17e90) {
      ref_increment (from core/process.c:93 = 0x73ec) { }
      net_step (from core/process.c:96 = 0x73f1) {
        net_poll (from net/netdevice.c:741 = 0xbce6) {
          netdev_poll (from net/netdevice.c:700 = 0xbc58) { }
          netdev_rx_dequeue (from net/netdevice.c:709 = 0xbc65) { }
        }
      }
      ref_decrement (from core/process.c:96 = 0x73f9) { }
    }

Note that inlined functions are reported, confusingly, as extra calls
to the *containing* function.  Minimise this confusion by adding the
attribute "no_instrument_function" to all functions declared as
inline.  (Static functions that have been inlined autonomously by gcc
will still be problematic, but these are far fewer in number.)

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2010-12-04 02:55:11 +00:00
parent f8a82c7d23
commit ea0fcb9460
4 changed files with 264 additions and 70 deletions
Download Patch File Download Diff File Expand all files Collapse all files

144
src/core/fnrec.c
View File

@@ -23,6 +23,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#include <string.h>
#include <ipxe/init.h>
#include <ipxe/uaccess.h>
#include <ipxe/io.h>
/** @file
*
@@ -30,12 +31,30 @@ FILE_LICENCE ( GPL2_OR_LATER );
*
*/
enum {
/** Constant for identifying valid trace buffers */
fnrec_magic = 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e',
/** Constant for identifying valid trace buffers */
#define FNREC_MAGIC ( 'f' << 24 | 'n' << 16 | 'r' << 8 | 'e' )
/** Trace buffer length */
fnrec_buffer_length = 4096 / sizeof ( unsigned long ),
/** Number of trace buffer entries */
#define FNREC_NUM_ENTRIES 4096
/** Trace buffer physical address
*
* Fixed at 17MB
*/
#define FNREC_PHYS_ADDRESS ( 17 * 1024 * 1024 )
/** A trace buffer entry */
struct fnrec_entry {
/** Called function address */
void *called_fn;
/** Call site */
void *call_site;
/** Entry count */
uint16_t entry_count;
/** Exit count */
uint16_t exit_count;
/** Checksum */
unsigned long checksum;
};
/** A trace buffer */
@@ -44,10 +63,11 @@ struct fnrec_buffer {
uint32_t magic;
/** Next trace buffer entry to fill */
uint32_t idx;
unsigned int idx;
/** Function address trace buffer */
unsigned long data[fnrec_buffer_length];
/** Trace buffer */
struct fnrec_entry data[FNREC_NUM_ENTRIES]
__attribute__ (( aligned ( 64 ) ));
};
/** The trace buffer */
@@ -59,7 +79,15 @@ static struct fnrec_buffer *fnrec_buffer;
* @ret is_valid Buffer is valid
*/
static int fnrec_is_valid ( void ) {
return fnrec_buffer && fnrec_buffer->magic == fnrec_magic;
return ( fnrec_buffer && ( fnrec_buffer->magic == FNREC_MAGIC ) );
}
/**
* Invalidate the trace buffer
*
*/
static void fnrec_invalidate ( void ) {
fnrec_buffer->magic = 0;
}
/**
@@ -67,43 +95,64 @@ static int fnrec_is_valid ( void ) {
*/
static void fnrec_reset ( void ) {
memset ( fnrec_buffer, 0, sizeof ( *fnrec_buffer ) );
fnrec_buffer->magic = fnrec_magic;
fnrec_buffer->magic = FNREC_MAGIC;
}
/**
* Write a value to the end of the buffer if it is not a repetition
* Append an entry to the trace buffer
*
* @v l Value to append
* @v called_fn Called function
* @v call_site Call site
* @ret entry Trace buffer entry
*/
static void fnrec_append_unique ( unsigned long l ) {
static unsigned long lastval;
uint32_t idx = fnrec_buffer->idx;
static struct fnrec_entry * fnrec_append ( void *called_fn, void *call_site ) {
struct fnrec_entry *entry;
/* Avoid recording the same value repeatedly */
if ( l == lastval )
return;
/* Re-use existing entry, if possible */
entry = &fnrec_buffer->data[ fnrec_buffer->idx ];
if ( ( entry->called_fn == called_fn ) &&
( entry->call_site == call_site ) &&
( entry->entry_count >= entry->exit_count ) ) {
return entry;
}
fnrec_buffer->data[idx] = l;
fnrec_buffer->idx = ( idx + 1 ) % fnrec_buffer_length;
lastval = l;
/* Otherwise, create a new entry */
fnrec_buffer->idx = ( ( fnrec_buffer->idx + 1 ) % FNREC_NUM_ENTRIES );
entry = &fnrec_buffer->data[ fnrec_buffer->idx ];
entry->called_fn = called_fn;
entry->call_site = call_site;
entry->entry_count = 0;
entry->exit_count = 0;
entry->checksum = ( ( ( unsigned long ) called_fn ) ^
( ( unsigned long ) call_site ) );
return entry;
}
/**
* Print the contents of the trace buffer in chronological order
*/
static void fnrec_dump ( void ) {
size_t i;
if ( !fnrec_is_valid() ) {
printf ( "fnrec buffer not found\n" );
return;
}
struct fnrec_entry *entry;
unsigned int i;
unsigned int idx;
unsigned long checksum;
printf ( "fnrec buffer dump:\n" );
for ( i = 0; i < fnrec_buffer_length; i++ ) {
unsigned long l = fnrec_buffer->data[
( fnrec_buffer->idx + i ) % fnrec_buffer_length];
printf ( "%08lx%c", l, i % 8 == 7 ? '\n' : ' ' );
for ( i = 1 ; i <= FNREC_NUM_ENTRIES ; i++ ) {
idx = ( ( fnrec_buffer->idx + i ) % FNREC_NUM_ENTRIES );
entry = &fnrec_buffer->data[idx];
if ( ( entry->entry_count == 0 ) && ( entry->exit_count == 0 ) )
continue;
checksum = ( ( ( ( unsigned long ) entry->called_fn ) ^
( ( unsigned long ) entry->call_site ) ) +
entry->entry_count + entry->exit_count );
printf ( "%p %p %d %d", entry->called_fn, entry->call_site,
entry->entry_count, entry->exit_count );
if ( entry->checksum != checksum ) {
printf ( " (checksum wrong at phys %08lx)",
virt_to_phys ( entry ) );
}
printf ( "\n");
}
}
@@ -111,9 +160,14 @@ static void fnrec_dump ( void ) {
* Function tracer initialisation function
*/
static void fnrec_init ( void ) {
/* Hardcoded to 17 MB */
fnrec_buffer = phys_to_virt ( 17 * 1024 * 1024 );
fnrec_dump();
fnrec_buffer = phys_to_virt ( FNREC_PHYS_ADDRESS );
if ( fnrec_is_valid() ) {
fnrec_invalidate();
fnrec_dump();
} else {
printf ( "fnrec buffer not found\n" );
}
fnrec_reset();
}
@@ -125,10 +179,24 @@ struct init_fn fnrec_init_fn __init_fn ( INIT_NORMAL ) = {
* These functions are called from every C function. The compiler inserts
* these calls when -finstrument-functions is used.
*/
void __cyg_profile_func_enter ( void *called_fn, void *call_site __unused ) {
if ( fnrec_is_valid() )
fnrec_append_unique ( ( unsigned long ) called_fn );
void __cyg_profile_func_enter ( void *called_fn, void *call_site ) {
struct fnrec_entry *entry;
if ( fnrec_is_valid() ) {
entry = fnrec_append ( called_fn, call_site );
entry->entry_count++;
entry->checksum++;
mb();
}
}
void __cyg_profile_func_exit ( void *called_fn __unused, void *call_site __unused ) {
void __cyg_profile_func_exit ( void *called_fn, void *call_site ) {
struct fnrec_entry *entry;
if ( fnrec_is_valid() ) {
entry = fnrec_append ( called_fn, call_site );
entry->exit_count++;
entry->checksum++;
mb();
}
}