mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-02 18:26:39 +07:00
d914ba37d7
Inorder to support recording of tgid, the following changes are made: * Introduce a new API (tracing_record_taskinfo) to additionally record the tgid along with the task's comm at the same time. This has has the benefit of not setting trace_cmdline_save before all the information for a task is saved. * Add a new API tracing_record_taskinfo_sched_switch to record task information for 2 tasks at a time (previous and next) and use it from sched_switch probe. * Preserve the old API (tracing_record_cmdline) and create it as a wrapper around the new one so that existing callers aren't affected. * Reuse the existing sched_switch and sched_wakeup probes to record tgid information and add a new option 'record-tgid' to enable recording of tgid When record-tgid option isn't enabled to being with, we take care to make sure that there's isn't memory or runtime overhead. Link: http://lkml.kernel.org/r/20170627020155.5139-1-joelaf@google.com Cc: kernel-team@android.com Cc: Ingo Molnar <mingo@redhat.com> Tested-by: Michael Sartain <mikesart@gmail.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
147 lines
3.0 KiB
C
147 lines
3.0 KiB
C
/*
|
|
* trace context switch
|
|
*
|
|
* Copyright (C) 2007 Steven Rostedt <srostedt@redhat.com>
|
|
*
|
|
*/
|
|
#include <linux/module.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/ftrace.h>
|
|
#include <trace/events/sched.h>
|
|
|
|
#include "trace.h"
|
|
|
|
#define RECORD_CMDLINE 1
|
|
#define RECORD_TGID 2
|
|
|
|
static int sched_cmdline_ref;
|
|
static int sched_tgid_ref;
|
|
static DEFINE_MUTEX(sched_register_mutex);
|
|
|
|
static void
|
|
probe_sched_switch(void *ignore, bool preempt,
|
|
struct task_struct *prev, struct task_struct *next)
|
|
{
|
|
int flags;
|
|
|
|
flags = (RECORD_TGID * !!sched_tgid_ref) +
|
|
(RECORD_CMDLINE * !!sched_cmdline_ref);
|
|
|
|
if (!flags)
|
|
return;
|
|
tracing_record_taskinfo_sched_switch(prev, next, flags);
|
|
}
|
|
|
|
static void
|
|
probe_sched_wakeup(void *ignore, struct task_struct *wakee)
|
|
{
|
|
int flags;
|
|
|
|
flags = (RECORD_TGID * !!sched_tgid_ref) +
|
|
(RECORD_CMDLINE * !!sched_cmdline_ref);
|
|
|
|
if (!flags)
|
|
return;
|
|
tracing_record_taskinfo(current, flags);
|
|
}
|
|
|
|
static int tracing_sched_register(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = register_trace_sched_wakeup(probe_sched_wakeup, NULL);
|
|
if (ret) {
|
|
pr_info("wakeup trace: Couldn't activate tracepoint"
|
|
" probe to kernel_sched_wakeup\n");
|
|
return ret;
|
|
}
|
|
|
|
ret = register_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
|
|
if (ret) {
|
|
pr_info("wakeup trace: Couldn't activate tracepoint"
|
|
" probe to kernel_sched_wakeup_new\n");
|
|
goto fail_deprobe;
|
|
}
|
|
|
|
ret = register_trace_sched_switch(probe_sched_switch, NULL);
|
|
if (ret) {
|
|
pr_info("sched trace: Couldn't activate tracepoint"
|
|
" probe to kernel_sched_switch\n");
|
|
goto fail_deprobe_wake_new;
|
|
}
|
|
|
|
return ret;
|
|
fail_deprobe_wake_new:
|
|
unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
|
|
fail_deprobe:
|
|
unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
|
|
return ret;
|
|
}
|
|
|
|
static void tracing_sched_unregister(void)
|
|
{
|
|
unregister_trace_sched_switch(probe_sched_switch, NULL);
|
|
unregister_trace_sched_wakeup_new(probe_sched_wakeup, NULL);
|
|
unregister_trace_sched_wakeup(probe_sched_wakeup, NULL);
|
|
}
|
|
|
|
static void tracing_start_sched_switch(int ops)
|
|
{
|
|
bool sched_register = (!sched_cmdline_ref && !sched_tgid_ref);
|
|
mutex_lock(&sched_register_mutex);
|
|
|
|
switch (ops) {
|
|
case RECORD_CMDLINE:
|
|
sched_cmdline_ref++;
|
|
break;
|
|
|
|
case RECORD_TGID:
|
|
sched_tgid_ref++;
|
|
break;
|
|
}
|
|
|
|
if (sched_register && (sched_cmdline_ref || sched_tgid_ref))
|
|
tracing_sched_register();
|
|
mutex_unlock(&sched_register_mutex);
|
|
}
|
|
|
|
static void tracing_stop_sched_switch(int ops)
|
|
{
|
|
mutex_lock(&sched_register_mutex);
|
|
|
|
switch (ops) {
|
|
case RECORD_CMDLINE:
|
|
sched_cmdline_ref--;
|
|
break;
|
|
|
|
case RECORD_TGID:
|
|
sched_tgid_ref--;
|
|
break;
|
|
}
|
|
|
|
if (!sched_cmdline_ref && !sched_tgid_ref)
|
|
tracing_sched_unregister();
|
|
mutex_unlock(&sched_register_mutex);
|
|
}
|
|
|
|
void tracing_start_cmdline_record(void)
|
|
{
|
|
tracing_start_sched_switch(RECORD_CMDLINE);
|
|
}
|
|
|
|
void tracing_stop_cmdline_record(void)
|
|
{
|
|
tracing_stop_sched_switch(RECORD_CMDLINE);
|
|
}
|
|
|
|
void tracing_start_tgid_record(void)
|
|
{
|
|
tracing_start_sched_switch(RECORD_TGID);
|
|
}
|
|
|
|
void tracing_stop_tgid_record(void)
|
|
{
|
|
tracing_stop_sched_switch(RECORD_TGID);
|
|
}
|