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Internal 64M buffer for profiling

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- when profiling is compiled in kernel includes a 64M buffer for
  sample

- 64M is the default used by profile tool as its buffer

- when using nmi profiling it is not possible to always copy sample
  stright to userland as the nmi may (and does) happen in bad moments

- reduces sampling overhead as samples are copied out only when
  profiling stops
This commit is contained in:
Tomas Hruby 2010-09-23 10:49:48 +00:00
parent e63b85a50b
commit 87c576584d
3 changed files with 20 additions and 18 deletions
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30
kernel/profile.c
View file

@ -63,32 +63,26 @@ PUBLIC void stop_profile_clock()
PRIVATE sprof_save_sample(struct proc * p)
{
struct sprof_sample s;
struct sprof_sample *s;
s.proc = p->p_endpoint;
s.pc = (void *) p->p_reg.pc;
s = (struct sprof_sample *) (sprof_sample_buffer + sprof_info.mem_used);
/* Store sample (process name and program counter). */
data_copy(KERNEL, (vir_bytes) &s,
sprof_ep, sprof_data_addr_vir + sprof_info.mem_used,
sizeof(s));
s->proc = p->p_endpoint;
s->pc = (void *) p->p_reg.pc;
sprof_info.mem_used += sizeof(s);
sprof_info.mem_used += sizeof(struct sprof_sample);
}
PRIVATE sprof_save_proc(struct proc * p)
{
struct sprof_proc s;
struct sprof_proc * s;
s.proc = p->p_endpoint;
memcpy(s.name, p->p_name, P_NAME_LEN);
s = (struct sprof_proc *) (sprof_sample_buffer + sprof_info.mem_used);
/* Store sample (process name and program counter). */
data_copy(KERNEL, (vir_bytes) &s,
sprof_ep, sprof_data_addr_vir + sprof_info.mem_used,
sizeof(s));
s->proc = p->p_endpoint;
memcpy(&s->name, p->p_name, P_NAME_LEN);
sprof_info.mem_used += sizeof(s);
sprof_info.mem_used += sizeof(struct sprof_proc);
}
PRIVATE void profile_sample(struct proc * p)
@ -100,7 +94,9 @@ PRIVATE void profile_sample(struct proc * p)
return;
/* Check if enough memory available before writing sample. */
if (sprof_info.mem_used + sizeof(sprof_info) > sprof_mem_size) {
if (sprof_info.mem_used + sizeof(sprof_info) +
2*sizeof(struct sprof_sample) +
2*sizeof(struct sprof_sample) > sprof_mem_size) {
sprof_info.mem_used = -1;
return;
}

3
kernel/profile.h
View file

@ -7,6 +7,9 @@
#include "arch_watchdog.h"
#define SAMPLE_BUFFER_SIZE (64 << 20)
EXTERN char sprof_sample_buffer[SAMPLE_BUFFER_SIZE];
EXTERN int sprofiling; /* whether profiling is running */
EXTERN int sprofiling_type; /* whether profiling is running */
EXTERN int sprof_mem_size; /* available user memory for data */

5
kernel/system/do_sprofile.c
View file

@ -65,7 +65,8 @@ PUBLIC int do_sprofile(struct proc * caller, message * m_ptr)
sprof_info.system_samples = 0;
sprof_info.user_samples = 0;
sprof_mem_size = m_ptr->PROF_MEM_SIZE;
sprof_mem_size = m_ptr->PROF_MEM_SIZE < SAMPLE_BUFFER_SIZE ?
m_ptr->PROF_MEM_SIZE : SAMPLE_BUFFER_SIZE;
switch (sprofiling_type = m_ptr->PROF_INTR_TYPE) {
case PROF_RTC:
@ -111,6 +112,8 @@ PUBLIC int do_sprofile(struct proc * caller, message * m_ptr)
data_copy(KERNEL, (vir_bytes) &sprof_info,
sprof_ep, sprof_info_addr_vir, sizeof(sprof_info));
data_copy(KERNEL, (vir_bytes) sprof_sample_buffer,
sprof_ep, sprof_data_addr_vir, sprof_info.mem_used);
clean_seen_flag();