+++ /dev/null
-/*
- * Copyright (C) 2008 Pekka Enberg, Eduard - Gabriel Munteanu
- *
- * This file is released under GPL version 2.
- */
-
-#include <linux/string.h>
-#include <linux/debugfs.h>
-#include <linux/relay.h>
-#include <linux/module.h>
-#include <linux/marker.h>
-#include <linux/gfp.h>
-#include <trace/kmemtrace.h>
-
-#define KMEMTRACE_SUBBUF_SIZE 524288
-#define KMEMTRACE_DEF_N_SUBBUFS 20
-
-static struct rchan *kmemtrace_chan;
-static u32 kmemtrace_buf_overruns;
-
-static unsigned int kmemtrace_n_subbufs;
-
-/* disabled by default */
-static unsigned int kmemtrace_enabled;
-
-/*
- * The sequence number is used for reordering kmemtrace packets
- * in userspace, since they are logged as per-CPU data.
- *
- * atomic_t should always be a 32-bit signed integer. Wraparound is not
- * likely to occur, but userspace can deal with it by expecting a certain
- * sequence number in the next packet that will be read.
- */
-static atomic_t kmemtrace_seq_num;
-
-#define KMEMTRACE_ABI_VERSION 1
-
-static u32 kmemtrace_abi_version __read_mostly = KMEMTRACE_ABI_VERSION;
-
-enum kmemtrace_event_id {
- KMEMTRACE_EVENT_ALLOC = 0,
- KMEMTRACE_EVENT_FREE,
-};
-
-struct kmemtrace_event {
- u8 event_id;
- u8 type_id;
- u16 event_size;
- s32 seq_num;
- u64 call_site;
- u64 ptr;
-} __attribute__ ((__packed__));
-
-struct kmemtrace_stats_alloc {
- u64 bytes_req;
- u64 bytes_alloc;
- u32 gfp_flags;
- s32 numa_node;
-} __attribute__ ((__packed__));
-
-static void kmemtrace_probe_alloc(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- unsigned long flags;
- struct kmemtrace_event *ev;
- struct kmemtrace_stats_alloc *stats;
- void *buf;
-
- local_irq_save(flags);
-
- buf = relay_reserve(kmemtrace_chan,
- sizeof(struct kmemtrace_event) +
- sizeof(struct kmemtrace_stats_alloc));
- if (!buf)
- goto failed;
-
- /*
- * Don't convert this to use structure initializers,
- * C99 does not guarantee the rvalues evaluation order.
- */
-
- ev = buf;
- ev->event_id = KMEMTRACE_EVENT_ALLOC;
- ev->type_id = va_arg(*args, int);
- ev->event_size = sizeof(struct kmemtrace_event) +
- sizeof(struct kmemtrace_stats_alloc);
- ev->seq_num = atomic_add_return(1, &kmemtrace_seq_num);
- ev->call_site = va_arg(*args, unsigned long);
- ev->ptr = va_arg(*args, unsigned long);
-
- stats = buf + sizeof(struct kmemtrace_event);
- stats->bytes_req = va_arg(*args, unsigned long);
- stats->bytes_alloc = va_arg(*args, unsigned long);
- stats->gfp_flags = va_arg(*args, unsigned long);
- stats->numa_node = va_arg(*args, int);
-
-failed:
- local_irq_restore(flags);
-}
-
-static void kmemtrace_probe_free(void *probe_data, void *call_data,
- const char *format, va_list *args)
-{
- unsigned long flags;
- struct kmemtrace_event *ev;
-
- local_irq_save(flags);
-
- ev = relay_reserve(kmemtrace_chan, sizeof(struct kmemtrace_event));
- if (!ev)
- goto failed;
-
- /*
- * Don't convert this to use structure initializers,
- * C99 does not guarantee the rvalues evaluation order.
- */
- ev->event_id = KMEMTRACE_EVENT_FREE;
- ev->type_id = va_arg(*args, int);
- ev->event_size = sizeof(struct kmemtrace_event);
- ev->seq_num = atomic_add_return(1, &kmemtrace_seq_num);
- ev->call_site = va_arg(*args, unsigned long);
- ev->ptr = va_arg(*args, unsigned long);
-
-failed:
- local_irq_restore(flags);
-}
-
-static struct dentry *
-kmemtrace_create_buf_file(const char *filename, struct dentry *parent,
- int mode, struct rchan_buf *buf, int *is_global)
-{
- return debugfs_create_file(filename, mode, parent, buf,
- &relay_file_operations);
-}
-
-static int kmemtrace_remove_buf_file(struct dentry *dentry)
-{
- debugfs_remove(dentry);
-
- return 0;
-}
-
-static int kmemtrace_subbuf_start(struct rchan_buf *buf,
- void *subbuf,
- void *prev_subbuf,
- size_t prev_padding)
-{
- if (relay_buf_full(buf)) {
- /*
- * We know it's not SMP-safe, but neither
- * debugfs_create_u32() is.
- */
- kmemtrace_buf_overruns++;
- return 0;
- }
-
- return 1;
-}
-
-static struct rchan_callbacks relay_callbacks = {
- .create_buf_file = kmemtrace_create_buf_file,
- .remove_buf_file = kmemtrace_remove_buf_file,
- .subbuf_start = kmemtrace_subbuf_start,
-};
-
-static struct dentry *kmemtrace_dir;
-static struct dentry *kmemtrace_overruns_dentry;
-static struct dentry *kmemtrace_abi_version_dentry;
-
-static struct dentry *kmemtrace_enabled_dentry;
-
-static int kmemtrace_start_probes(void)
-{
- int err;
-
- err = marker_probe_register("kmemtrace_alloc", "type_id %d "
- "call_site %lu ptr %lu "
- "bytes_req %lu bytes_alloc %lu "
- "gfp_flags %lu node %d",
- kmemtrace_probe_alloc, NULL);
- if (err)
- return err;
- err = marker_probe_register("kmemtrace_free", "type_id %d "
- "call_site %lu ptr %lu",
- kmemtrace_probe_free, NULL);
-
- return err;
-}
-
-static void kmemtrace_stop_probes(void)
-{
- marker_probe_unregister("kmemtrace_alloc",
- kmemtrace_probe_alloc, NULL);
- marker_probe_unregister("kmemtrace_free",
- kmemtrace_probe_free, NULL);
-}
-
-static int kmemtrace_enabled_get(void *data, u64 *val)
-{
- *val = *((int *) data);
-
- return 0;
-}
-
-static int kmemtrace_enabled_set(void *data, u64 val)
-{
- u64 old_val = kmemtrace_enabled;
-
- *((int *) data) = !!val;
-
- if (old_val == val)
- return 0;
- if (val)
- kmemtrace_start_probes();
- else
- kmemtrace_stop_probes();
-
- return 0;
-}
-
-DEFINE_SIMPLE_ATTRIBUTE(kmemtrace_enabled_fops,
- kmemtrace_enabled_get,
- kmemtrace_enabled_set, "%llu\n");
-
-static void kmemtrace_cleanup(void)
-{
- if (kmemtrace_enabled_dentry)
- debugfs_remove(kmemtrace_enabled_dentry);
-
- kmemtrace_stop_probes();
-
- if (kmemtrace_abi_version_dentry)
- debugfs_remove(kmemtrace_abi_version_dentry);
- if (kmemtrace_overruns_dentry)
- debugfs_remove(kmemtrace_overruns_dentry);
-
- relay_close(kmemtrace_chan);
- kmemtrace_chan = NULL;
-
- if (kmemtrace_dir)
- debugfs_remove(kmemtrace_dir);
-}
-
-static int __init kmemtrace_setup_late(void)
-{
- if (!kmemtrace_chan)
- goto failed;
-
- kmemtrace_dir = debugfs_create_dir("kmemtrace", NULL);
- if (!kmemtrace_dir)
- goto cleanup;
-
- kmemtrace_abi_version_dentry =
- debugfs_create_u32("abi_version", S_IRUSR,
- kmemtrace_dir, &kmemtrace_abi_version);
- kmemtrace_overruns_dentry =
- debugfs_create_u32("total_overruns", S_IRUSR,
- kmemtrace_dir, &kmemtrace_buf_overruns);
- if (!kmemtrace_overruns_dentry || !kmemtrace_abi_version_dentry)
- goto cleanup;
-
- kmemtrace_enabled_dentry =
- debugfs_create_file("enabled", S_IRUSR | S_IWUSR,
- kmemtrace_dir, &kmemtrace_enabled,
- &kmemtrace_enabled_fops);
- if (!kmemtrace_enabled_dentry)
- goto cleanup;
-
- if (relay_late_setup_files(kmemtrace_chan, "cpu", kmemtrace_dir))
- goto cleanup;
-
- printk(KERN_INFO "kmemtrace: fully up.\n");
-
- return 0;
-
-cleanup:
- kmemtrace_cleanup();
-failed:
- return 1;
-}
-late_initcall(kmemtrace_setup_late);
-
-static int __init kmemtrace_set_boot_enabled(char *str)
-{
- if (!str)
- return -EINVAL;
-
- if (!strcmp(str, "yes"))
- kmemtrace_enabled = 1;
- else if (!strcmp(str, "no"))
- kmemtrace_enabled = 0;
- else
- return -EINVAL;
-
- return 0;
-}
-early_param("kmemtrace.enable", kmemtrace_set_boot_enabled);
-
-static int __init kmemtrace_set_subbufs(char *str)
-{
- get_option(&str, &kmemtrace_n_subbufs);
- return 0;
-}
-early_param("kmemtrace.subbufs", kmemtrace_set_subbufs);
-
-void kmemtrace_init(void)
-{
- if (!kmemtrace_n_subbufs)
- kmemtrace_n_subbufs = KMEMTRACE_DEF_N_SUBBUFS;
-
- kmemtrace_chan = relay_open(NULL, NULL, KMEMTRACE_SUBBUF_SIZE,
- kmemtrace_n_subbufs, &relay_callbacks,
- NULL);
- if (!kmemtrace_chan) {
- printk(KERN_ERR "kmemtrace: could not open relay channel.\n");
- return;
- }
-
- if (!kmemtrace_enabled) {
- printk(KERN_INFO "kmemtrace: disabled. Pass "
- "kemtrace.enable=yes as kernel parameter for "
- "boot-time tracing.\n");
- return;
- }
- if (kmemtrace_start_probes()) {
- printk(KERN_ERR "kmemtrace: could not register marker probes!\n");
- kmemtrace_cleanup();
- return;
- }
-
- printk(KERN_INFO "kmemtrace: enabled.\n");
-}
-
projects / cascardo / linux.git / commitdiff