mirror of
https://github.com/varun-r-mallya/sysprof.git
synced 2026-02-11 15:40:53 +00:00
Communicate traces to userspace through shared memory instead of copying.
2006-10-22 Soren Sandmann <sandmann@daimi.au.dk> Communicate traces to userspace through shared memory instead of copying. * module/sysprof-module.c: Store the traces in a SysprofMmapArea. (sysprof_mmap): Implement this method. (sysprof_nopage): Implement this. (sysprof_read): Just reset the tail pointer and return zero. * module/sysprof-module.h (struct SysprofMmapArea): New structure. * collector.c (collector_stop): Unmap the device (in_dead_period): New function (on_read): Read the traces out of mmap()ed area instead of reading them. Call read() to prevent poll() from firing. (struct Collector): New members map_area and current. * Makefile.am (insert-module): Prefix modprobe with /sbin * collector.c (open_fd): mmap() the sysprof device.
This commit is contained in:
Soren Sandmann
committed by
Søren Sandmann Pedersen
Søren Sandmann Pedersen
parent
5eb19d00fa
commit
4dd37d092c
114
collector.c
114
collector.c
@ -29,6 +29,9 @@
|
||||
#include <sys/types.h>
|
||||
#include <fcntl.h>
|
||||
#include <unistd.h>
|
||||
#include <sys/mman.h>
|
||||
|
||||
#define SYSPROF_FILE "/dev/sysprof-trace"
|
||||
|
||||
static void set_no_module_error (GError **err);
|
||||
static void set_cant_open_error (GError **err, int eno);
|
||||
@ -42,12 +45,14 @@ struct Collector
|
||||
int fd;
|
||||
GTimeVal latest_reset;
|
||||
int n_samples;
|
||||
SysprofMmapArea * map_area;
|
||||
unsigned int current;
|
||||
};
|
||||
|
||||
/* callback is called whenever a new sample arrives */
|
||||
Collector *
|
||||
collector_new (CollectorFunc callback,
|
||||
gpointer data)
|
||||
gpointer data)
|
||||
{
|
||||
Collector *collector = g_new0 (Collector, 1);
|
||||
|
||||
@ -80,7 +85,7 @@ time_diff (const GTimeVal *first,
|
||||
#define RESET_DEAD_PERIOD 250
|
||||
|
||||
static void
|
||||
add_trace_to_stash (SysprofStackTrace *trace,
|
||||
add_trace_to_stash (const SysprofStackTrace *trace,
|
||||
StackStash *stash)
|
||||
{
|
||||
int i;
|
||||
@ -105,46 +110,64 @@ add_trace_to_stash (SysprofStackTrace *trace,
|
||||
g_free (addrs);
|
||||
}
|
||||
|
||||
static void
|
||||
on_read (gpointer data)
|
||||
static gboolean
|
||||
in_dead_period (Collector *collector)
|
||||
{
|
||||
SysprofStackTrace trace;
|
||||
Collector *collector = data;
|
||||
GTimeVal now;
|
||||
int rd;
|
||||
double diff;
|
||||
|
||||
rd = read (collector->fd, &trace, sizeof (trace));
|
||||
|
||||
if (rd == -1 && errno == EWOULDBLOCK)
|
||||
return;
|
||||
|
||||
g_get_current_time (&now);
|
||||
|
||||
diff = time_diff (&now, &collector->latest_reset);
|
||||
|
||||
if (diff >= 0.0 && diff < RESET_DEAD_PERIOD)
|
||||
return TRUE;
|
||||
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
static void
|
||||
on_read (gpointer data)
|
||||
{
|
||||
Collector *collector = data;
|
||||
char c;
|
||||
|
||||
/* Make sure poll() doesn't fire immediately again */
|
||||
read (collector->fd, &c, 1);
|
||||
|
||||
/* After a reset we ignore samples for a short period so that
|
||||
* a reset will actually cause 'samples' to become 0
|
||||
*/
|
||||
diff = time_diff (&now, &collector->latest_reset);
|
||||
|
||||
if (diff >= 0.0 && diff < RESET_DEAD_PERIOD)
|
||||
if (in_dead_period (collector))
|
||||
{
|
||||
collector->current = collector->map_area->head;
|
||||
return;
|
||||
|
||||
#if 0
|
||||
{
|
||||
int i;
|
||||
g_print ("pid: %d (%d)\n", trace.pid, trace.n_addresses);
|
||||
for (i=0; i < trace.n_addresses; ++i)
|
||||
g_print ("rd: %08x\n", trace.addresses[i]);
|
||||
g_print ("-=-\n");
|
||||
}
|
||||
#endif
|
||||
|
||||
if (rd > 0)
|
||||
while (collector->current != collector->map_area->head)
|
||||
{
|
||||
add_trace_to_stash (&trace, collector->stash);
|
||||
const SysprofStackTrace *trace;
|
||||
|
||||
trace = &(collector->map_area->traces[collector->current]);
|
||||
|
||||
#if 0
|
||||
{
|
||||
int i;
|
||||
g_print ("pid: %d (%d)\n", trace.pid, trace.n_addresses);
|
||||
for (i=0; i < trace.n_addresses; ++i)
|
||||
g_print ("rd: %08x\n", trace.addresses[i]);
|
||||
g_print ("-=-\n");
|
||||
}
|
||||
#endif
|
||||
|
||||
add_trace_to_stash (trace, collector->stash);
|
||||
|
||||
collector->current++;
|
||||
if (collector->current >= SYSPROF_N_TRACES)
|
||||
collector->current = 0;
|
||||
|
||||
collector->n_samples++;
|
||||
|
||||
|
||||
if (collector->callback)
|
||||
collector->callback (collector->data);
|
||||
}
|
||||
@ -176,6 +199,7 @@ open_fd (Collector *collector,
|
||||
GError **err)
|
||||
{
|
||||
int fd;
|
||||
void *map_area;
|
||||
|
||||
fd = open (SYSPROF_FILE, O_RDONLY);
|
||||
if (fd < 0)
|
||||
@ -183,16 +207,16 @@ open_fd (Collector *collector,
|
||||
if (load_module())
|
||||
{
|
||||
GTimer *timer = g_timer_new ();
|
||||
|
||||
|
||||
while (fd < 0 && g_timer_elapsed (timer, NULL) < 0.5)
|
||||
{
|
||||
/* Wait for udev to discover the new device */
|
||||
usleep (100000);
|
||||
|
||||
|
||||
errno = 0;
|
||||
fd = open (SYSPROF_FILE, O_RDONLY);
|
||||
}
|
||||
|
||||
|
||||
g_timer_destroy (timer);
|
||||
|
||||
if (fd < 0)
|
||||
@ -201,7 +225,7 @@ open_fd (Collector *collector,
|
||||
return FALSE;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
if (fd < 0)
|
||||
{
|
||||
set_no_module_error (err);
|
||||
@ -210,6 +234,18 @@ open_fd (Collector *collector,
|
||||
}
|
||||
}
|
||||
|
||||
map_area = mmap (NULL, sizeof (SysprofMmapArea), PROT_READ, MAP_SHARED, fd, 0);
|
||||
|
||||
if (map_area == MAP_FAILED)
|
||||
{
|
||||
close (fd);
|
||||
set_cant_open_error (err, errno);
|
||||
|
||||
return FALSE;
|
||||
}
|
||||
|
||||
collector->map_area = map_area;
|
||||
collector->current = 0;
|
||||
collector->fd = fd;
|
||||
fd_add_watch (collector->fd, collector);
|
||||
|
||||
@ -218,7 +254,7 @@ open_fd (Collector *collector,
|
||||
|
||||
gboolean
|
||||
collector_start (Collector *collector,
|
||||
GError **err)
|
||||
GError **err)
|
||||
{
|
||||
if (collector->fd < 0 && !open_fd (collector, err))
|
||||
return FALSE;
|
||||
@ -234,6 +270,10 @@ collector_stop (Collector *collector)
|
||||
{
|
||||
fd_remove_watch (collector->fd);
|
||||
|
||||
munmap (collector->map_area, sizeof (SysprofMmapArea));
|
||||
collector->map_area = NULL;
|
||||
collector->current = 0;
|
||||
|
||||
close (collector->fd);
|
||||
collector->fd = -1;
|
||||
}
|
||||
@ -244,7 +284,7 @@ collector_reset (Collector *collector)
|
||||
{
|
||||
if (collector->stash)
|
||||
stack_stash_unref (collector->stash);
|
||||
|
||||
|
||||
process_flush_caches();
|
||||
|
||||
collector->stash = stack_stash_new (NULL);
|
||||
@ -316,7 +356,7 @@ resolve_symbols (GList *trace, gint size, gpointer data)
|
||||
stack_stash_add_trace (info->resolved_stash,
|
||||
(gulong *)resolved_trace->pdata,
|
||||
resolved_trace->len, size);
|
||||
|
||||
|
||||
g_ptr_array_free (resolved_trace, TRUE);
|
||||
}
|
||||
|
||||
@ -330,13 +370,13 @@ collector_create_profile (Collector *collector)
|
||||
info.unique_symbols = g_hash_table_new (g_direct_hash, g_direct_equal);
|
||||
|
||||
stack_stash_foreach (collector->stash, resolve_symbols, &info);
|
||||
|
||||
|
||||
/* FIXME: we are leaking the value strings in info.unique_symbols */
|
||||
|
||||
g_hash_table_destroy (info.unique_symbols);
|
||||
|
||||
|
||||
profile = profile_new (info.resolved_stash);
|
||||
|
||||
|
||||
stack_stash_unref (info.resolved_stash);
|
||||
|
||||
return profile;
|
||||
|
||||
Reference in New Issue
Block a user