/*
- * Copyright (C) 2006 Jens Axboe <axboe@suse.de>
+ * Copyright (C) 2006 Jens Axboe <axboe@kernel.dk>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
+#include <linux/time.h>
#include <asm/uaccess.h>
static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, };
static unsigned int blktrace_seq __read_mostly = 1;
/*
- * Send out a notify for this process, if we haven't done so since a trace
- * started
+ * Send out a notify message.
*/
-static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
+static void trace_note(struct blk_trace *bt, pid_t pid, int action,
+ const void *data, size_t len)
{
struct blk_io_trace *t;
- t = relay_reserve(bt->rchan, sizeof(*t) + sizeof(tsk->comm));
+ t = relay_reserve(bt->rchan, sizeof(*t) + len);
if (t) {
+ const int cpu = smp_processor_id();
+
t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION;
+ t->time = sched_clock() - per_cpu(blk_trace_cpu_offset, cpu);
t->device = bt->dev;
- t->action = BLK_TC_ACT(BLK_TC_NOTIFY);
- t->pid = tsk->pid;
- t->cpu = smp_processor_id();
- t->pdu_len = sizeof(tsk->comm);
- memcpy((void *) t + sizeof(*t), tsk->comm, t->pdu_len);
- tsk->btrace_seq = blktrace_seq;
+ t->action = action;
+ t->pid = pid;
+ t->cpu = cpu;
+ t->pdu_len = len;
+ memcpy((void *) t + sizeof(*t), data, len);
}
}
+/*
+ * Send out a notify for this process, if we haven't done so since a trace
+ * started
+ */
+static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
+{
+ tsk->btrace_seq = blktrace_seq;
+ trace_note(bt, tsk->pid, BLK_TN_PROCESS, tsk->comm, sizeof(tsk->comm));
+}
+
+static void trace_note_time(struct blk_trace *bt)
+{
+ struct timespec now;
+ unsigned long flags;
+ u32 words[2];
+
+ getnstimeofday(&now);
+ words[0] = now.tv_sec;
+ words[1] = now.tv_nsec;
+
+ local_irq_save(flags);
+ trace_note(bt, 0, BLK_TN_TIMESTAMP, words, sizeof(words));
+ local_irq_restore(flags);
+}
+
static int act_log_check(struct blk_trace *bt, u32 what, sector_t sector,
pid_t pid)
{
/*
* Bio action bits of interest
*/
-static u32 bio_act[5] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD) };
+static u32 bio_act[9] __read_mostly = { 0, BLK_TC_ACT(BLK_TC_BARRIER), BLK_TC_ACT(BLK_TC_SYNC), 0, BLK_TC_ACT(BLK_TC_AHEAD), 0, 0, 0, BLK_TC_ACT(BLK_TC_META) };
/*
* More could be added as needed, taking care to increment the decrementer
(((rw) & (1 << BIO_RW_SYNC)) >> (BIO_RW_SYNC - 1))
#define trace_ahead_bit(rw) \
(((rw) & (1 << BIO_RW_AHEAD)) << (2 - BIO_RW_AHEAD))
+#define trace_meta_bit(rw) \
+ (((rw) & (1 << BIO_RW_META)) >> (BIO_RW_META - 3))
/*
* The worker for the various blk_add_trace*() types. Fills out a
what |= bio_act[trace_barrier_bit(rw)];
what |= bio_act[trace_sync_bit(rw)];
what |= bio_act[trace_ahead_bit(rw)];
+ what |= bio_act[trace_meta_bit(rw)];
pid = tsk->pid;
if (unlikely(act_log_check(bt, what, sector, pid)))
return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
}
-static struct file_operations blk_dropped_fops = {
+static const struct file_operations blk_dropped_fops = {
.owner = THIS_MODULE,
.open = blk_dropped_open,
.read = blk_dropped_read,
if (!bt->dropped_file)
goto err;
- bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks);
+ bt->rchan = relay_open("trace", dir, buts.buf_size, buts.buf_nr, &blk_relay_callbacks, bt);
if (!bt->rchan)
goto err;
- bt->rchan->private_data = bt;
bt->act_mask = buts.act_mask;
if (!bt->act_mask)
if (bt) {
if (bt->dropped_file)
debugfs_remove(bt->dropped_file);
- if (bt->sequence)
- free_percpu(bt->sequence);
+ free_percpu(bt->sequence);
if (bt->rchan)
relay_close(bt->rchan);
kfree(bt);
blktrace_seq++;
smp_mb();
bt->trace_state = Blktrace_running;
+
+ trace_note_time(bt);
ret = 0;
}
} else {
*t -= (a + b) / 2;
}
+/*
+ * calibrate our inter-CPU timings
+ */
static void blk_trace_check_cpu_time(void *data)
{
unsigned long long *t;
put_cpu();
}
-/*
- * Call blk_trace_check_cpu_time() on each CPU to calibrate our inter-CPU
- * timings
- */
-static void blk_trace_calibrate_offsets(void)
-{
- unsigned long flags;
-
- smp_call_function(blk_trace_check_cpu_time, NULL, 1, 1);
- local_irq_save(flags);
- blk_trace_check_cpu_time(NULL);
- local_irq_restore(flags);
-}
-
static void blk_trace_set_ht_offsets(void)
{
#if defined(CONFIG_SCHED_SMT)
static __init int blk_trace_init(void)
{
mutex_init(&blk_tree_mutex);
- blk_trace_calibrate_offsets();
+ on_each_cpu(blk_trace_check_cpu_time, NULL, 1, 1);
blk_trace_set_ht_offsets();
return 0;