linux/kernel/trace/kmemtrace.c
Paul Mundt f9ac5a69ed kmemtrace: Fix up tracer registration
Commit ddc1637af2 ("kmemtrace: Print
binary output only if 'bin' option is set") ended up inverting the
error detection logic. register_tracer() returns 0 on success,
which this change caused to treat as an error, resulting in:

[    0.132000] Warning: could not register the kmem tracer

as well as bailing out of the initcall with an error value. This
restores the old logic.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
LKML-Reference: <20090928075540.GD6668@linux-sh.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-01 11:53:44 +02:00

511 lines
12 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/tracepoint.h>
#include <linux/seq_file.h>
#include <linux/debugfs.h>
#include <linux/dcache.h>
#include <linux/fs.h>
#include <linux/kmemtrace.h>
#include "trace_output.h"
#include "trace.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 struct trace_array *kmemtrace_array;
/* Trace allocations */
static inline void kmemtrace_alloc(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 ftrace_event_call *call = &event_kmem_alloc;
struct trace_array *tr = kmemtrace_array;
struct kmemtrace_alloc_entry *entry;
struct ring_buffer_event *event;
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
if (!event)
return;
entry = ring_buffer_event_data(event);
tracing_generic_entry_update(&entry->ent, 0, 0);
entry->ent.type = TRACE_KMEM_ALLOC;
entry->type_id = type_id;
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;
if (!filter_check_discard(call, entry, tr->buffer, event))
ring_buffer_unlock_commit(tr->buffer, event);
trace_wake_up();
}
static inline void kmemtrace_free(enum kmemtrace_type_id type_id,
unsigned long call_site,
const void *ptr)
{
struct ftrace_event_call *call = &event_kmem_free;
struct trace_array *tr = kmemtrace_array;
struct kmemtrace_free_entry *entry;
struct ring_buffer_event *event;
event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry));
if (!event)
return;
entry = ring_buffer_event_data(event);
tracing_generic_entry_update(&entry->ent, 0, 0);
entry->ent.type = TRACE_KMEM_FREE;
entry->type_id = type_id;
entry->call_site = call_site;
entry->ptr = ptr;
if (!filter_check_discard(call, entry, tr->buffer, event))
ring_buffer_unlock_commit(tr->buffer, event);
trace_wake_up();
}
static void kmemtrace_kmalloc(unsigned long call_site,
const void *ptr,
size_t bytes_req,
size_t bytes_alloc,
gfp_t gfp_flags)
{
kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
bytes_req, bytes_alloc, gfp_flags, -1);
}
static void kmemtrace_kmem_cache_alloc(unsigned long call_site,
const void *ptr,
size_t bytes_req,
size_t bytes_alloc,
gfp_t gfp_flags)
{
kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
bytes_req, bytes_alloc, gfp_flags, -1);
}
static void kmemtrace_kmalloc_node(unsigned long call_site,
const void *ptr,
size_t bytes_req,
size_t bytes_alloc,
gfp_t gfp_flags,
int node)
{
kmemtrace_alloc(KMEMTRACE_TYPE_KMALLOC, call_site, ptr,
bytes_req, bytes_alloc, gfp_flags, node);
}
static void kmemtrace_kmem_cache_alloc_node(unsigned long call_site,
const void *ptr,
size_t bytes_req,
size_t bytes_alloc,
gfp_t gfp_flags,
int node)
{
kmemtrace_alloc(KMEMTRACE_TYPE_CACHE, call_site, ptr,
bytes_req, bytes_alloc, gfp_flags, node);
}
static void kmemtrace_kfree(unsigned long call_site, const void *ptr)
{
kmemtrace_free(KMEMTRACE_TYPE_KMALLOC, call_site, ptr);
}
static void kmemtrace_kmem_cache_free(unsigned long call_site, const void *ptr)
{
kmemtrace_free(KMEMTRACE_TYPE_CACHE, call_site, ptr);
}
static int kmemtrace_start_probes(void)
{
int err;
err = register_trace_kmalloc(kmemtrace_kmalloc);
if (err)
return err;
err = register_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
if (err)
return err;
err = register_trace_kmalloc_node(kmemtrace_kmalloc_node);
if (err)
return err;
err = register_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
if (err)
return err;
err = register_trace_kfree(kmemtrace_kfree);
if (err)
return err;
err = register_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
return err;
}
static void kmemtrace_stop_probes(void)
{
unregister_trace_kmalloc(kmemtrace_kmalloc);
unregister_trace_kmem_cache_alloc(kmemtrace_kmem_cache_alloc);
unregister_trace_kmalloc_node(kmemtrace_kmalloc_node);
unregister_trace_kmem_cache_alloc_node(kmemtrace_kmem_cache_alloc_node);
unregister_trace_kfree(kmemtrace_kfree);
unregister_trace_kmem_cache_free(kmemtrace_kmem_cache_free);
}
static int kmem_trace_init(struct trace_array *tr)
{
kmemtrace_array = tr;
tracing_reset_online_cpus(tr);
kmemtrace_start_probes();
return 0;
}
static void kmem_trace_reset(struct trace_array *tr)
{
kmemtrace_stop_probes();
}
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 following functions give the original output from kmemtrace,
* plus the origin CPU, since reordering occurs in-kernel now.
*/
#define KMEMTRACE_USER_ALLOC 0
#define KMEMTRACE_USER_FREE 1
struct kmemtrace_user_event {
u8 event_id;
u8 type_id;
u16 event_size;
u32 cpu;
u64 timestamp;
unsigned long call_site;
unsigned long ptr;
};
struct kmemtrace_user_event_alloc {
size_t bytes_req;
size_t bytes_alloc;
unsigned gfp_flags;
int node;
};
static enum print_line_t
kmemtrace_print_alloc(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct kmemtrace_alloc_entry *entry;
int ret;
trace_assign_type(entry, iter->ent);
ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu "
"bytes_req %lu bytes_alloc %lu gfp_flags %lu node %d\n",
entry->type_id, (void *)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(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct kmemtrace_free_entry *entry;
int ret;
trace_assign_type(entry, iter->ent);
ret = trace_seq_printf(s, "type_id %d call_site %pF ptr %lu\n",
entry->type_id, (void *)entry->call_site,
(unsigned long)entry->ptr);
if (!ret)
return TRACE_TYPE_PARTIAL_LINE;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
kmemtrace_print_alloc_user(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct kmemtrace_alloc_entry *entry;
struct kmemtrace_user_event *ev;
struct kmemtrace_user_event_alloc *ev_alloc;
trace_assign_type(entry, iter->ent);
ev = trace_seq_reserve(s, sizeof(*ev));
if (!ev)
return TRACE_TYPE_PARTIAL_LINE;
ev->event_id = KMEMTRACE_USER_ALLOC;
ev->type_id = entry->type_id;
ev->event_size = sizeof(*ev) + sizeof(*ev_alloc);
ev->cpu = iter->cpu;
ev->timestamp = iter->ts;
ev->call_site = entry->call_site;
ev->ptr = (unsigned long)entry->ptr;
ev_alloc = trace_seq_reserve(s, sizeof(*ev_alloc));
if (!ev_alloc)
return TRACE_TYPE_PARTIAL_LINE;
ev_alloc->bytes_req = entry->bytes_req;
ev_alloc->bytes_alloc = entry->bytes_alloc;
ev_alloc->gfp_flags = entry->gfp_flags;
ev_alloc->node = entry->node;
return TRACE_TYPE_HANDLED;
}
static enum print_line_t
kmemtrace_print_free_user(struct trace_iterator *iter, int flags)
{
struct trace_seq *s = &iter->seq;
struct kmemtrace_free_entry *entry;
struct kmemtrace_user_event *ev;
trace_assign_type(entry, iter->ent);
ev = trace_seq_reserve(s, sizeof(*ev));
if (!ev)
return TRACE_TYPE_PARTIAL_LINE;
ev->event_id = KMEMTRACE_USER_FREE;
ev->type_id = entry->type_id;
ev->event_size = sizeof(*ev);
ev->cpu = iter->cpu;
ev->timestamp = iter->ts;
ev->call_site = entry->call_site;
ev->ptr = (unsigned long)entry->ptr;
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;
trace_assign_type(entry, iter->ent);
/* 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 and call site*/
ret = trace_seq_printf(s, "%4d %pf\n", entry->node,
(void *)entry->call_site);
if (!ret)
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;
trace_assign_type(entry, iter->ent);
/* 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 and print call site*/
ret = trace_seq_printf(s, " %pf\n", (void *)entry->call_site);
if (!ret)
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;
if (!(kmem_tracer_flags.val & TRACE_KMEM_OPT_MINIMAL))
return TRACE_TYPE_UNHANDLED;
switch (entry->type) {
case TRACE_KMEM_ALLOC:
return kmemtrace_print_alloc_compress(iter);
case TRACE_KMEM_FREE:
return kmemtrace_print_free_compress(iter);
default:
return TRACE_TYPE_UNHANDLED;
}
}
static struct trace_event kmem_trace_alloc = {
.type = TRACE_KMEM_ALLOC,
.trace = kmemtrace_print_alloc,
.binary = kmemtrace_print_alloc_user,
};
static struct trace_event kmem_trace_free = {
.type = TRACE_KMEM_FREE,
.trace = kmemtrace_print_free,
.binary = kmemtrace_print_free_user,
};
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)
{
if (!register_ftrace_event(&kmem_trace_alloc)) {
pr_warning("Warning: could not register kmem events\n");
return 1;
}
if (!register_ftrace_event(&kmem_trace_free)) {
pr_warning("Warning: could not register kmem events\n");
return 1;
}
if (register_tracer(&kmem_tracer) != 0) {
pr_warning("Warning: could not register the kmem tracer\n");
return 1;
}
return 0;
}
device_initcall(init_kmem_tracer);