X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=block%2Fblktrace.c;h=568588cd16b22d546771e18fb4e34f9be4811afe;hb=6da127ad0918f93ea93678dad62ce15ffed18797;hp=498a0a54a6aa664f27edce4a32d2fb2d37f4c110;hpb=35fc51e7a5056889421270c1fb63d8ec45fbccf4;p=safe%2Fjmp%2Flinux-2.6 diff --git a/block/blktrace.c b/block/blktrace.c index 498a0a5..568588c 100644 --- a/block/blktrace.c +++ b/block/blktrace.c @@ -25,7 +25,6 @@ #include #include -static DEFINE_PER_CPU(unsigned long long, blk_trace_cpu_offset) = { 0, }; static unsigned int blktrace_seq __read_mostly = 1; /* @@ -41,7 +40,7 @@ static void trace_note(struct blk_trace *bt, pid_t pid, int action, const int cpu = smp_processor_id(); t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; - t->time = cpu_clock(cpu) - per_cpu(blk_trace_cpu_offset, cpu); + t->time = ktime_to_ns(ktime_get()); t->device = bt->dev; t->action = action; t->pid = pid; @@ -159,7 +158,7 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, t->magic = BLK_IO_TRACE_MAGIC | BLK_IO_TRACE_VERSION; t->sequence = ++(*sequence); - t->time = cpu_clock(cpu) - per_cpu(blk_trace_cpu_offset, cpu); + t->time = ktime_to_ns(ktime_get()); t->sector = sector; t->bytes = bytes; t->action = what; @@ -179,7 +178,7 @@ void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes, EXPORT_SYMBOL_GPL(__blk_add_trace); static struct dentry *blk_tree_root; -static struct mutex blk_tree_mutex; +static DEFINE_MUTEX(blk_tree_mutex); static unsigned int root_users; static inline void blk_remove_root(void) @@ -236,7 +235,7 @@ static void blk_trace_cleanup(struct blk_trace *bt) kfree(bt); } -static int blk_trace_remove(struct request_queue *q) +int blk_trace_remove(struct request_queue *q) { struct blk_trace *bt; @@ -250,6 +249,7 @@ static int blk_trace_remove(struct request_queue *q) return 0; } +EXPORT_SYMBOL_GPL(blk_trace_remove); static int blk_dropped_open(struct inode *inode, struct file *filp) { @@ -317,18 +317,17 @@ static struct rchan_callbacks blk_relay_callbacks = { /* * Setup everything required to start tracing */ -int do_blk_trace_setup(struct request_queue *q, struct block_device *bdev, +int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev, struct blk_user_trace_setup *buts) { struct blk_trace *old_bt, *bt = NULL; struct dentry *dir = NULL; - char b[BDEVNAME_SIZE]; int ret, i; if (!buts->buf_size || !buts->buf_nr) return -EINVAL; - strcpy(buts->name, bdevname(bdev, b)); + strcpy(buts->name, name); /* * some device names have larger paths - convert the slashes @@ -353,7 +352,7 @@ int do_blk_trace_setup(struct request_queue *q, struct block_device *bdev, goto err; bt->dir = dir; - bt->dev = bdev->bd_dev; + bt->dev = dev; atomic_set(&bt->dropped, 0); ret = -EIO; @@ -400,8 +399,8 @@ err: return ret; } -static int blk_trace_setup(struct request_queue *q, struct block_device *bdev, - char __user *arg) +int blk_trace_setup(struct request_queue *q, char *name, dev_t dev, + char __user *arg) { struct blk_user_trace_setup buts; int ret; @@ -410,7 +409,7 @@ static int blk_trace_setup(struct request_queue *q, struct block_device *bdev, if (ret) return -EFAULT; - ret = do_blk_trace_setup(q, bdev, &buts); + ret = do_blk_trace_setup(q, name, dev, &buts); if (ret) return ret; @@ -419,8 +418,9 @@ static int blk_trace_setup(struct request_queue *q, struct block_device *bdev, return 0; } +EXPORT_SYMBOL_GPL(blk_trace_setup); -static int blk_trace_startstop(struct request_queue *q, int start) +int blk_trace_startstop(struct request_queue *q, int start) { struct blk_trace *bt; int ret; @@ -453,6 +453,7 @@ static int blk_trace_startstop(struct request_queue *q, int start) return ret; } +EXPORT_SYMBOL_GPL(blk_trace_startstop); /** * blk_trace_ioctl: - handle the ioctls associated with tracing @@ -465,6 +466,7 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) { struct request_queue *q; int ret, start = 0; + char b[BDEVNAME_SIZE]; q = bdev_get_queue(bdev); if (!q) @@ -474,7 +476,8 @@ int blk_trace_ioctl(struct block_device *bdev, unsigned cmd, char __user *arg) switch (cmd) { case BLKTRACESETUP: - ret = blk_trace_setup(q, bdev, arg); + strcpy(b, bdevname(bdev, b)); + ret = blk_trace_setup(q, b, bdev->bd_dev, arg); break; case BLKTRACESTART: start = 1; @@ -505,77 +508,3 @@ void blk_trace_shutdown(struct request_queue *q) blk_trace_remove(q); } } - -/* - * Average offset over two calls to cpu_clock() with a gettimeofday() - * in the middle - */ -static void blk_check_time(unsigned long long *t, int this_cpu) -{ - unsigned long long a, b; - struct timeval tv; - - a = cpu_clock(this_cpu); - do_gettimeofday(&tv); - b = cpu_clock(this_cpu); - - *t = tv.tv_sec * 1000000000 + tv.tv_usec * 1000; - *t -= (a + b) / 2; -} - -/* - * calibrate our inter-CPU timings - */ -static void blk_trace_check_cpu_time(void *data) -{ - unsigned long long *t; - int this_cpu = get_cpu(); - - t = &per_cpu(blk_trace_cpu_offset, this_cpu); - - /* - * Just call it twice, hopefully the second call will be cache hot - * and a little more precise - */ - blk_check_time(t, this_cpu); - blk_check_time(t, this_cpu); - - put_cpu(); -} - -static void blk_trace_set_ht_offsets(void) -{ -#if defined(CONFIG_SCHED_SMT) - int cpu, i; - - /* - * now make sure HT siblings have the same time offset - */ - preempt_disable(); - for_each_online_cpu(cpu) { - unsigned long long *cpu_off, *sibling_off; - - for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu)) { - if (i == cpu) - continue; - - cpu_off = &per_cpu(blk_trace_cpu_offset, cpu); - sibling_off = &per_cpu(blk_trace_cpu_offset, i); - *sibling_off = *cpu_off; - } - } - preempt_enable(); -#endif -} - -static __init int blk_trace_init(void) -{ - mutex_init(&blk_tree_mutex); - on_each_cpu(blk_trace_check_cpu_time, NULL, 1, 1); - blk_trace_set_ht_offsets(); - - return 0; -} - -module_init(blk_trace_init); -