linux/kernel/trace/kmemtrace.c
Arnaldo Carvalho de Melo 51a763dd84 tracing: Introduce trace_buffer_{lock_reserve,unlock_commit}
Impact: new API

These new functions do what previously was being open coded, reducing
the number of details ftrace plugin writers have to worry about.

It also standardizes the handling of stacktrace, userstacktrace and
other trace options we may introduce in the future.

With this patch, for instance, the blk tracer (and some others already
in the tree) can use the "userstacktrace" /d/tracing/trace_options
facility.

$ codiff /tmp/vmlinux.before /tmp/vmlinux.after
linux-2.6-tip/kernel/trace/trace.c:
  trace_vprintk              |   -5
  trace_graph_return         |  -22
  trace_graph_entry          |  -26
  trace_function             |  -45
  __ftrace_trace_stack       |  -27
  ftrace_trace_userstack     |  -29
  tracing_sched_switch_trace |  -66
  tracing_stop               |   +1
  trace_seq_to_user          |   -1
  ftrace_trace_special       |  -63
  ftrace_special             |   +1
  tracing_sched_wakeup_trace |  -70
  tracing_reset_online_cpus  |   -1
 13 functions changed, 2 bytes added, 355 bytes removed, diff: -353

linux-2.6-tip/block/blktrace.c:
  __blk_add_trace |  -58
 1 function changed, 58 bytes removed, diff: -58

linux-2.6-tip/kernel/trace/trace.c:
  trace_buffer_lock_reserve  |  +88
  trace_buffer_unlock_commit |  +86
 2 functions changed, 174 bytes added, diff: +174

/tmp/vmlinux.after:
 16 functions changed, 176 bytes added, 413 bytes removed, diff: -237

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Frédéric Weisbecker <fweisbec@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-06 01:01:41 +01:00

339 lines
7.9 KiB
C

/*
* Memory allocator tracing
*
* Copyright (C) 2008 Eduard - Gabriel Munteanu
* Copyright (C) 2008 Pekka Enberg <penberg@cs.helsinki.fi>
* Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com>
*/
#include <linux/dcache.h>
#include <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/seq_file.h>
#include <trace/kmemtrace.h>
#include "trace.h"
#include "trace_output.h"
/* Select an alternative, minimalistic output than the original one */
#define TRACE_KMEM_OPT_MINIMAL 0x1
static struct tracer_opt kmem_opts[] = {
/* Default disable the minimalistic output */
{ TRACER_OPT(kmem_minimalistic, TRACE_KMEM_OPT_MINIMAL) },
{ }
};
static struct tracer_flags kmem_tracer_flags = {
.val = 0,
.opts = kmem_opts
};
static bool kmem_tracing_enabled __read_mostly;
static struct trace_array *kmemtrace_array;
static int kmem_trace_init(struct trace_array *tr)
{
int cpu;
kmemtrace_array = tr;
for_each_cpu_mask(cpu, cpu_possible_map)
tracing_reset(tr, cpu);
kmem_tracing_enabled = true;
return 0;
}
static void kmem_trace_reset(struct trace_array *tr)
{
kmem_tracing_enabled = false;
}
static void kmemtrace_headers(struct seq_file *s)
{
/* Don't need headers for the original kmemtrace output */
if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
return;
seq_printf(s, "#\n");
seq_printf(s, "# ALLOC TYPE REQ GIVEN FLAGS "
" POINTER NODE CALLER\n");
seq_printf(s, "# FREE | | | | "
" | | | |\n");
seq_printf(s, "# |\n\n");
}
/*
* The two following functions give the original output from kmemtrace,
* or something close to....perhaps they need some missing things
*/
static enum print_line_t
kmemtrace_print_alloc_original(struct trace_iterator *iter,
struct kmemtrace_alloc_entry *entry)
{
struct trace_seq *s = &iter->seq;
int ret;
/* Taken from the old linux/kmemtrace.h */
ret = trace_seq_printf(s, "type_id %d call_site %lu ptr %lu "
"bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
entry->type_id, entry->call_site, (unsigned long) entry->ptr,
(unsigned long) entry->bytes_req, (unsigned long) entry->bytes_alloc,
(unsigned long) entry->gfp_flags, entry->node);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
kmemtrace_print_free_original(struct trace_iterator *iter,
struct kmemtrace_free_entry *entry)
{
struct trace_seq *s = &iter->seq;
int ret;
/* Taken from the old linux/kmemtrace.h */
ret = trace_seq_printf(s, "type_id %d call_site %lu ptr %lu\n",
entry->type_id, entry->call_site, (unsigned long) entry->ptr);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
/* The two other following provide a more minimalistic output */
static enum print_line_t
kmemtrace_print_alloc_compress(struct trace_iterator *iter,
struct kmemtrace_alloc_entry *entry)
{
struct trace_seq *s = &iter->seq;
int ret;
/* Alloc entry */
ret = trace_seq_printf(s, " + ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Type */
switch (entry->type_id) {
case KMEMTRACE_TYPE_KMALLOC:
ret = trace_seq_printf(s, "K ");
break;
case KMEMTRACE_TYPE_CACHE:
ret = trace_seq_printf(s, "C ");
break;
case KMEMTRACE_TYPE_PAGES:
ret = trace_seq_printf(s, "P ");
break;
default:
ret = trace_seq_printf(s, "? ");
}
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Requested */
ret = trace_seq_printf(s, "%4zu ", entry->bytes_req);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Allocated */
ret = trace_seq_printf(s, "%4zu ", entry->bytes_alloc);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Flags
* TODO: would be better to see the name of the GFP flag names
*/
ret = trace_seq_printf(s, "%08x ", entry->gfp_flags);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Pointer to allocated */
ret = trace_seq_printf(s, "0x%tx ", (ptrdiff_t)entry->ptr);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Node */
ret = trace_seq_printf(s, "%4d ", entry->node);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Call site */
ret = seq_print_ip_sym(s, entry->call_site, 0);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
if (!trace_seq_printf(s, "\n"))
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
kmemtrace_print_free_compress(struct trace_iterator *iter,
struct kmemtrace_free_entry *entry)
{
struct trace_seq *s = &iter->seq;
int ret;
/* Free entry */
ret = trace_seq_printf(s, " - ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Type */
switch (entry->type_id) {
case KMEMTRACE_TYPE_KMALLOC:
ret = trace_seq_printf(s, "K ");
break;
case KMEMTRACE_TYPE_CACHE:
ret = trace_seq_printf(s, "C ");
break;
case KMEMTRACE_TYPE_PAGES:
ret = trace_seq_printf(s, "P ");
break;
default:
ret = trace_seq_printf(s, "? ");
}
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Skip requested/allocated/flags */
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Pointer to allocated */
ret = trace_seq_printf(s, "0x%tx ", (ptrdiff_t)entry->ptr);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Skip node */
ret = trace_seq_printf(s, " ");
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
/* Call site */
ret = seq_print_ip_sym(s, entry->call_site, 0);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
if (!trace_seq_printf(s, "\n"))
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t kmemtrace_print_line(struct trace_iterator *iter)
{
struct trace_entry *entry = iter->ent;
switch (entry->type) {
case TRACE_KMEM_ALLOC: {
struct kmemtrace_alloc_entry *field;
trace_assign_type(field, entry);
if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
return kmemtrace_print_alloc_compress(iter, field);
else
return kmemtrace_print_alloc_original(iter, field);
}
case TRACE_KMEM_FREE: {
struct kmemtrace_free_entry *field;
trace_assign_type(field, entry);
if (kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL)
return kmemtrace_print_free_compress(iter, field);
else
return kmemtrace_print_free_original(iter, field);
}
default:
return TRACE_TYPE_UNHANDLED;
}
}
/* Trace allocations */
void kmemtrace_mark_alloc_node(enum kmemtrace_type_id type_id,
unsigned long call_site,
const void *ptr,
size_t bytes_req,
size_t bytes_alloc,
gfp_t gfp_flags,
int node)
{
struct ring_buffer_event *event;
struct kmemtrace_alloc_entry *entry;
struct trace_array *tr = kmemtrace_array;
if (!kmem_tracing_enabled)
return;
event = trace_buffer_lock_reserve(tr, TRACE_KMEM_ALLOC,
sizeof(*entry), 0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->call_site = call_site;
entry->ptr = ptr;
entry->bytes_req = bytes_req;
entry->bytes_alloc = bytes_alloc;
entry->gfp_flags = gfp_flags;
entry->node = node;
trace_buffer_unlock_commit(tr, event, 0, 0);
}
EXPORT_SYMBOL(kmemtrace_mark_alloc_node);
void kmemtrace_mark_free(enum kmemtrace_type_id type_id,
unsigned long call_site,
const void *ptr)
{
struct ring_buffer_event *event;
struct kmemtrace_free_entry *entry;
struct trace_array *tr = kmemtrace_array;
if (!kmem_tracing_enabled)
return;
event = trace_buffer_lock_reserve(tr, TRACE_KMEM_FREE,
sizeof(*entry), 0, 0);
if (!event)
return;
entry = ring_buffer_event_data(event);
entry->type_id = type_id;
entry->call_site = call_site;
entry->ptr = ptr;
trace_buffer_unlock_commit(tr, event, 0, 0);
}
EXPORT_SYMBOL(kmemtrace_mark_free);
static struct tracer kmem_tracer __read_mostly = {
.name = "kmemtrace",
.init = kmem_trace_init,
.reset = kmem_trace_reset,
.print_line = kmemtrace_print_line,
.print_header = kmemtrace_headers,
.flags = &kmem_tracer_flags
};
void kmemtrace_init(void)
{
/* earliest opportunity to start kmem tracing */
}
static int __init init_kmem_tracer(void)
{
return register_tracer(&kmem_tracer);
}
device_initcall(init_kmem_tracer);