Re: [PATCH][v3] blktrace: conversion to tracepoints 2.6.27.4backport

From: Mathieu Desnoyers
Date: Thu Oct 30 2008 - 10:44:54 EST

Hi Arnaldo,

I've backported it to 2.6.27.4 so I can merge it in my current -lttng
tree. (I'll move to 2.6.28-rc soon though). I send it here for future
reference.

Mathieu


Em Wed, Oct 29, 2008 at 02:18:55PM +0100, Jens Axboe escreveu:
> > Feel free to point any disgusting aspect, perhaps there is at
> > least one to warn me about fixing 8-)
>
> You my as well pass the members separately now that it's a specific call
> anyway, to avoid doing the calculation when tracing is disabled.
>
> Patch looks straight forward. Perhaps it would be cleaner to use an
> atomic type for the reference?

Done and made the old pdu_int + NULL bio (trace_block_unplug_{io,timer})
functions to receive just the request_queue.

Found and fixed a bug in the process:

In v2 we had:

+ unregister_trace_block_rq_insert(blk_add_trace_rq_insert);
+ unregister_trace_block_rq_insert(blk_add_trace_rq_abort);

Where it should have been:

+ unregister_trace_block_rq_insert(blk_add_trace_rq_insert);
+ unregister_trace_block_rq_abort(blk_add_trace_rq_abort);

c'n'p roblem!

Also removed the leftover tracepoint_synchronize_unregister macro, it
was already merged righfully as an inline function.

Everything should be rock solid now 8)

Regards,

- Arnaldo

commit 61205226c1aed87e444c3e0e4a271aee76c57589
Author: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Date: Wed Oct 29 17:23:47 2008 -0200

blktrace: port to tracepoints

This was a forward port of work done by Mathieu Desnoyers, I changed it to
encode the 'what' parameter on the tracepoint name, so that one can register
interest in specific events and not on classes of events to then check the
'what' parameter.

Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

Ported to 2.6.27.4 LTTng tree by Mathieu Desnoyers. "abort event" is not used.

Also :

static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
int rw = rq->cmd_flags & 0x03;

if (likely(!bt))
return;

#if 0 //port to 2.6.27.4
if (blk_discard_rq(rq))
rw |= (1 << BIO_RW_DISCARD);
#endif //0


Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>
---
block/Kconfig | 1
block/blk-core.c | 33 +---
block/blktrace.c | 334 ++++++++++++++++++++++++++++++++++++++++++-
block/elevator.c | 5
drivers/md/dm.c | 6
fs/bio.c | 3
include/linux/blktrace_api.h | 143 ------------------
include/trace/block.h | 60 +++++++
mm/bounce.c | 3
9 files changed, 422 insertions(+), 166 deletions(-)

Index: linux-2.6-lttng/block/Kconfig
===================================================================
--- linux-2.6-lttng.orig/block/Kconfig 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/block/Kconfig 2008-10-30 10:02:04.000000000 -0400
@@ -47,6 +47,7 @@ config BLK_DEV_IO_TRACE
depends on SYSFS
select RELAY
select DEBUG_FS
+ select TRACEPOINTS
help
Say Y here if you want to be able to trace the block layer actions
on a given queue. Tracing allows you to see any traffic happening
Index: linux-2.6-lttng/block/blk-core.c
===================================================================
--- linux-2.6-lttng.orig/block/blk-core.c 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/block/blk-core.c 2008-10-30 10:02:42.000000000 -0400
@@ -30,6 +30,7 @@
#include <linux/cpu.h>
#include <linux/blktrace_api.h>
#include <linux/fault-inject.h>
+#include <trace/block.h>

#include "blk.h"

@@ -207,7 +208,7 @@ void blk_plug_device(struct request_queu

if (!queue_flag_test_and_set(QUEUE_FLAG_PLUGGED, q)) {
mod_timer(&q->unplug_timer, jiffies + q->unplug_delay);
- blk_add_trace_generic(q, NULL, 0, BLK_TA_PLUG);
+ trace_block_plug(q);
}
}
EXPORT_SYMBOL(blk_plug_device);
@@ -295,9 +296,7 @@ void blk_unplug_work(struct work_struct
struct request_queue *q =
container_of(work, struct request_queue, unplug_work);

- blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
- q->rq.count[READ] + q->rq.count[WRITE]);
-
+ trace_block_unplug_io(q);
q->unplug_fn(q);
}

@@ -305,9 +304,7 @@ void blk_unplug_timeout(unsigned long da
{
struct request_queue *q = (struct request_queue *)data;

- blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_TIMER, NULL,
- q->rq.count[READ] + q->rq.count[WRITE]);
-
+ trace_block_unplug_timer(q);
kblockd_schedule_work(&q->unplug_work);
}

@@ -317,9 +314,7 @@ void blk_unplug(struct request_queue *q)
* devices don't necessarily have an ->unplug_fn defined
*/
if (q->unplug_fn) {
- blk_add_trace_pdu_int(q, BLK_TA_UNPLUG_IO, NULL,
- q->rq.count[READ] + q->rq.count[WRITE]);
-
+ trace_block_unplug_io(q);
q->unplug_fn(q);
}
}
@@ -806,7 +801,7 @@ rq_starved:
if (ioc_batching(q, ioc))
ioc->nr_batch_requests--;

- blk_add_trace_generic(q, bio, rw, BLK_TA_GETRQ);
+ trace_block_getrq(q, bio, rw);
out:
return rq;
}
@@ -832,7 +827,7 @@ static struct request *get_request_wait(
prepare_to_wait_exclusive(&rl->wait[rw], &wait,
TASK_UNINTERRUPTIBLE);

- blk_add_trace_generic(q, bio, rw, BLK_TA_SLEEPRQ);
+ trace_block_sleeprq(q, bio, rw);

__generic_unplug_device(q);
spin_unlock_irq(q->queue_lock);
@@ -907,7 +902,7 @@ EXPORT_SYMBOL(blk_start_queueing);
*/
void blk_requeue_request(struct request_queue *q, struct request *rq)
{
- blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
+ trace_block_rq_requeue(q, rq);

if (blk_rq_tagged(rq))
blk_queue_end_tag(q, rq);
@@ -1132,7 +1127,7 @@ static int __make_request(struct request
if (!ll_back_merge_fn(q, req, bio))
break;

- blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
+ trace_block_bio_backmerge(q, bio);

req->biotail->bi_next = bio;
req->biotail = bio;
@@ -1149,7 +1144,7 @@ static int __make_request(struct request
if (!ll_front_merge_fn(q, req, bio))
break;

- blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
+ trace_block_bio_frontmerge(q, bio);

bio->bi_next = req->bio;
req->bio = bio;
@@ -1228,7 +1223,7 @@ static inline void blk_partition_remap(s
bio->bi_sector += p->start_sect;
bio->bi_bdev = bdev->bd_contains;

- blk_add_trace_remap(bdev_get_queue(bio->bi_bdev), bio,
+ trace_block_remap(bdev_get_queue(bio->bi_bdev), bio,
bdev->bd_dev, bio->bi_sector,
bio->bi_sector - p->start_sect);
}
@@ -1399,10 +1394,10 @@ end_io:
goto end_io;

if (old_sector != -1)
- blk_add_trace_remap(q, bio, old_dev, bio->bi_sector,
+ trace_block_remap(q, bio, old_dev, bio->bi_sector,
old_sector);

- blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
+ trace_block_bio_queue(q, bio);

old_sector = bio->bi_sector;
old_dev = bio->bi_bdev->bd_dev;
@@ -1536,7 +1531,7 @@ static int __end_that_request_first(stru
int total_bytes, bio_nbytes, next_idx = 0;
struct bio *bio;

- blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
+ trace_block_rq_complete(req->q, req);

/*
* for a REQ_BLOCK_PC request, we want to carry any eventual
Index: linux-2.6-lttng/block/blktrace.c
===================================================================
--- linux-2.6-lttng.orig/block/blktrace.c 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/block/blktrace.c 2008-10-30 10:33:06.000000000 -0400
@@ -23,10 +23,18 @@
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/time.h>
+#include <trace/block.h>
#include <asm/uaccess.h>

static unsigned int blktrace_seq __read_mostly = 1;

+/* Global reference count of probes */
+static DEFINE_MUTEX(blk_probe_mutex);
+static atomic_t blk_probes_ref = ATOMIC_INIT(0);
+
+static int blk_register_tracepoints(void);
+static void blk_unregister_tracepoints(void);
+
/*
* Send out a notify message.
*/
@@ -133,7 +141,7 @@ static u32 bio_act[9] __read_mostly = {
* The worker for the various blk_add_trace*() types. Fills out a
* blk_io_trace structure and places it in a per-cpu subbuffer.
*/
-void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
+static void __blk_add_trace(struct blk_trace *bt, sector_t sector, int bytes,
int rw, u32 what, int error, int pdu_len, void *pdu_data)
{
struct task_struct *tsk = current;
@@ -190,8 +198,6 @@ void __blk_add_trace(struct blk_trace *b
local_irq_restore(flags);
}

-EXPORT_SYMBOL_GPL(__blk_add_trace);
-
static struct dentry *blk_tree_root;
static DEFINE_MUTEX(blk_tree_mutex);
static unsigned int root_users;
@@ -250,6 +256,10 @@ static void blk_trace_cleanup(struct blk
free_percpu(bt->sequence);
free_percpu(bt->msg_data);
kfree(bt);
+ mutex_lock(&blk_probe_mutex);
+ if (atomic_dec_and_test(&blk_probes_ref))
+ blk_unregister_tracepoints();
+ mutex_unlock(&blk_probe_mutex);
}

int blk_trace_remove(struct request_queue *q)
@@ -440,6 +450,14 @@ int do_blk_trace_setup(struct request_qu
bt->pid = buts->pid;
bt->trace_state = Blktrace_setup;

+ mutex_lock(&blk_probe_mutex);
+ if (atomic_add_return(1, &blk_probes_ref) == 1) {
+ ret = blk_register_tracepoints();
+ if (ret)
+ goto probe_err;
+ }
+ mutex_unlock(&blk_probe_mutex);
+
ret = -EBUSY;
old_bt = xchg(&q->blk_trace, bt);
if (old_bt) {
@@ -448,6 +466,9 @@ int do_blk_trace_setup(struct request_qu
}

return 0;
+probe_err:
+ atomic_dec(&blk_probes_ref);
+ mutex_unlock(&blk_probe_mutex);
err:
if (dir)
blk_remove_tree(dir);
@@ -574,3 +595,310 @@ void blk_trace_shutdown(struct request_q
blk_trace_remove(q);
}
}
+
+/*
+ * blktrace probes
+ */
+
+/**
+ * blk_add_trace_rq - Add a trace for a request oriented action
+ * @q: queue the io is for
+ * @rq: the source request
+ * @what: the action
+ *
+ * Description:
+ * Records an action against a request. Will log the bio offset + size.
+ *
+ **/
+static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+ u32 what)
+{
+ struct blk_trace *bt = q->blk_trace;
+ int rw = rq->cmd_flags & 0x03;
+
+ if (likely(!bt))
+ return;
+
+#if 0 //port to 2.6.27.4
+ if (blk_discard_rq(rq))
+ rw |= (1 << BIO_RW_DISCARD);
+#endif //0
+
+ if (blk_pc_request(rq)) {
+ what |= BLK_TC_ACT(BLK_TC_PC);
+ __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors,
+ sizeof(rq->cmd), rq->cmd);
+ } else {
+ what |= BLK_TC_ACT(BLK_TC_FS);
+ __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+ rw, what, rq->errors, 0, NULL);
+ }
+}
+
+static void blk_add_trace_rq_abort(struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(q, rq, BLK_TA_ABORT);
+}
+
+static void blk_add_trace_rq_insert(struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+}
+
+static void blk_add_trace_rq_issue(struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+}
+
+static void blk_add_trace_rq_requeue(struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(q, rq, BLK_TA_REQUEUE);
+}
+
+static void blk_add_trace_rq_complete(struct request_queue *q, struct request *rq)
+{
+ blk_add_trace_rq(q, rq, BLK_TA_COMPLETE);
+}
+
+/**
+ * blk_add_trace_bio - Add a trace for a bio oriented action
+ * @q: queue the io is for
+ * @bio: the source bio
+ * @what: the action
+ *
+ * Description:
+ * Records an action against a bio. Will log the bio offset + size.
+ *
+ **/
+static void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
+ u32 what)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (likely(!bt))
+ return;
+
+ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what,
+ !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
+}
+
+static void blk_add_trace_bio_bounce(struct request_queue *q, struct bio *bio)
+{
+ blk_add_trace_bio(q, bio, BLK_TA_BOUNCE);
+}
+
+static void blk_add_trace_bio_complete(struct request_queue *q, struct bio *bio)
+{
+ blk_add_trace_bio(q, bio, BLK_TA_COMPLETE);
+}
+
+static void blk_add_trace_bio_backmerge(struct request_queue *q, struct bio *bio)
+{
+ blk_add_trace_bio(q, bio, BLK_TA_BACKMERGE);
+}
+
+static void blk_add_trace_bio_frontmerge(struct request_queue *q, struct bio *bio)
+{
+ blk_add_trace_bio(q, bio, BLK_TA_FRONTMERGE);
+}
+
+static void blk_add_trace_bio_queue(struct request_queue *q, struct bio *bio)
+{
+ blk_add_trace_bio(q, bio, BLK_TA_QUEUE);
+}
+
+static void blk_add_trace_getrq(struct request_queue *q, struct bio *bio, int rw)
+{
+ if (bio)
+ blk_add_trace_bio(q, bio, BLK_TA_GETRQ);
+ else {
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt)
+ __blk_add_trace(bt, 0, 0, rw, BLK_TA_GETRQ, 0, 0, NULL);
+ }
+}
+
+
+static void blk_add_trace_sleeprq(struct request_queue *q, struct bio *bio, int rw)
+{
+ if (bio)
+ blk_add_trace_bio(q, bio, BLK_TA_SLEEPRQ);
+ else {
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt)
+ __blk_add_trace(bt, 0, 0, rw, BLK_TA_SLEEPRQ, 0, 0, NULL);
+ }
+}
+
+static void blk_add_trace_plug(struct request_queue *q)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt)
+ __blk_add_trace(bt, 0, 0, 0, BLK_TA_PLUG, 0, 0, NULL);
+}
+
+static void blk_add_trace_unplug_io(struct request_queue *q)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt) {
+ unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
+ __be64 rpdu = cpu_to_be64(pdu);
+
+ __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_IO, 0,
+ sizeof(rpdu), &rpdu);
+ }
+}
+
+static void blk_add_trace_unplug_timer(struct request_queue *q)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt) {
+ unsigned int pdu = q->rq.count[READ] + q->rq.count[WRITE];
+ __be64 rpdu = cpu_to_be64(pdu);
+
+ __blk_add_trace(bt, 0, 0, 0, BLK_TA_UNPLUG_TIMER, 0,
+ sizeof(rpdu), &rpdu);
+ }
+}
+
+static void blk_add_trace_split(struct request_queue *q, struct bio *bio,
+ unsigned int pdu)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (bt) {
+ __be64 rpdu = cpu_to_be64(pdu);
+
+ __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw,
+ BLK_TA_SPLIT, !bio_flagged(bio, BIO_UPTODATE),
+ sizeof(rpdu), &rpdu);
+ }
+}
+
+/**
+ * blk_add_trace_remap - Add a trace for a remap operation
+ * @q: queue the io is for
+ * @bio: the source bio
+ * @dev: target device
+ * @from: source sector
+ * @to: target sector
+ *
+ * Description:
+ * Device mapper or raid target sometimes need to split a bio because
+ * it spans a stripe (or similar). Add a trace for that action.
+ *
+ **/
+static void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
+ dev_t dev, sector_t from, sector_t to)
+{
+ struct blk_trace *bt = q->blk_trace;
+ struct blk_io_trace_remap r;
+
+ if (likely(!bt))
+ return;
+
+ r.device = cpu_to_be32(dev);
+ r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
+ r.sector = cpu_to_be64(to);
+
+ __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP,
+ !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
+}
+
+/**
+ * blk_add_driver_data - Add binary message with driver-specific data
+ * @q: queue the io is for
+ * @rq: io request
+ * @data: driver-specific data
+ * @len: length of driver-specific data
+ *
+ * Description:
+ * Some drivers might want to write driver-specific data per request.
+ *
+ **/
+void blk_add_driver_data(struct request_queue *q,
+ struct request *rq,
+ void *data, size_t len)
+{
+ struct blk_trace *bt = q->blk_trace;
+
+ if (likely(!bt))
+ return;
+
+ if (blk_pc_request(rq))
+ __blk_add_trace(bt, 0, rq->data_len, 0, BLK_TA_DRV_DATA,
+ rq->errors, len, data);
+ else
+ __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,
+ 0, BLK_TA_DRV_DATA, rq->errors, len, data);
+}
+EXPORT_SYMBOL_GPL(blk_add_driver_data);
+
+static int blk_register_tracepoints(void)
+{
+ int ret;
+
+ ret = register_trace_block_rq_abort(blk_add_trace_rq_abort);
+ WARN_ON(ret);
+ ret = register_trace_block_rq_insert(blk_add_trace_rq_insert);
+ WARN_ON(ret);
+ ret = register_trace_block_rq_issue(blk_add_trace_rq_issue);
+ WARN_ON(ret);
+ ret = register_trace_block_rq_requeue(blk_add_trace_rq_requeue);
+ WARN_ON(ret);
+ ret = register_trace_block_rq_complete(blk_add_trace_rq_complete);
+ WARN_ON(ret);
+ ret = register_trace_block_bio_bounce(blk_add_trace_bio_bounce);
+ WARN_ON(ret);
+ ret = register_trace_block_bio_complete(blk_add_trace_bio_complete);
+ WARN_ON(ret);
+ ret = register_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
+ WARN_ON(ret);
+ ret = register_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
+ WARN_ON(ret);
+ ret = register_trace_block_bio_queue(blk_add_trace_bio_queue);
+ WARN_ON(ret);
+ ret = register_trace_block_getrq(blk_add_trace_getrq);
+ WARN_ON(ret);
+ ret = register_trace_block_sleeprq(blk_add_trace_sleeprq);
+ WARN_ON(ret);
+ ret = register_trace_block_plug(blk_add_trace_plug);
+ WARN_ON(ret);
+ ret = register_trace_block_unplug_timer(blk_add_trace_unplug_timer);
+ WARN_ON(ret);
+ ret = register_trace_block_unplug_io(blk_add_trace_unplug_io);
+ WARN_ON(ret);
+ ret = register_trace_block_split(blk_add_trace_split);
+ WARN_ON(ret);
+ ret = register_trace_block_remap(blk_add_trace_remap);
+ WARN_ON(ret);
+ return 0;
+}
+
+static void blk_unregister_tracepoints(void)
+{
+ unregister_trace_block_remap(blk_add_trace_remap);
+ unregister_trace_block_split(blk_add_trace_split);
+ unregister_trace_block_unplug_io(blk_add_trace_unplug_io);
+ unregister_trace_block_unplug_timer(blk_add_trace_unplug_timer);
+ unregister_trace_block_plug(blk_add_trace_plug);
+ unregister_trace_block_sleeprq(blk_add_trace_sleeprq);
+ unregister_trace_block_getrq(blk_add_trace_getrq);
+ unregister_trace_block_bio_queue(blk_add_trace_bio_queue);
+ unregister_trace_block_bio_frontmerge(blk_add_trace_bio_frontmerge);
+ unregister_trace_block_bio_backmerge(blk_add_trace_bio_backmerge);
+ unregister_trace_block_bio_complete(blk_add_trace_bio_complete);
+ unregister_trace_block_bio_bounce(blk_add_trace_bio_bounce);
+ unregister_trace_block_rq_complete(blk_add_trace_rq_complete);
+ unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue);
+ unregister_trace_block_rq_issue(blk_add_trace_rq_issue);
+ unregister_trace_block_rq_insert(blk_add_trace_rq_insert);
+ unregister_trace_block_rq_abort(blk_add_trace_rq_abort);
+
+ tracepoint_synchronize_unregister();
+}
Index: linux-2.6-lttng/block/elevator.c
===================================================================
--- linux-2.6-lttng.orig/block/elevator.c 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/block/elevator.c 2008-10-30 10:03:15.000000000 -0400
@@ -33,6 +33,7 @@
#include <linux/compiler.h>
#include <linux/delay.h>
#include <linux/blktrace_api.h>
+#include <trace/block.h>
#include <linux/hash.h>

#include <asm/uaccess.h>
@@ -577,7 +578,7 @@ void elv_insert(struct request_queue *q,
unsigned ordseq;
int unplug_it = 1;

- blk_add_trace_rq(q, rq, BLK_TA_INSERT);
+ trace_block_rq_insert(q, rq);

rq->q = q;

@@ -763,7 +764,7 @@ struct request *elv_next_request(struct
* not be passed by new incoming requests
*/
rq->cmd_flags |= REQ_STARTED;
- blk_add_trace_rq(q, rq, BLK_TA_ISSUE);
+ trace_block_rq_issue(q, rq);
}

if (!q->boundary_rq || q->boundary_rq == rq) {
Index: linux-2.6-lttng/drivers/md/dm.c
===================================================================
--- linux-2.6-lttng.orig/drivers/md/dm.c 2008-10-30 10:01:11.000000000 -0400
+++ linux-2.6-lttng/drivers/md/dm.c 2008-10-30 10:04:25.000000000 -0400
@@ -22,6 +22,7 @@
#include <linux/hdreg.h>
#include <linux/blktrace_api.h>
#include <linux/smp_lock.h>
+#include <trace/block.h>

#define DM_MSG_PREFIX "core"

@@ -514,8 +515,7 @@ static void dec_pending(struct dm_io *io
wake_up(&io->md->wait);

if (io->error != DM_ENDIO_REQUEUE) {
- blk_add_trace_bio(io->md->queue, io->bio,
- BLK_TA_COMPLETE);
+ trace_block_bio_complete(io->md->queue, io->bio);

bio_endio(io->bio, io->error);
}
@@ -608,7 +608,7 @@ static void __map_bio(struct dm_target *
if (r == DM_MAPIO_REMAPPED) {
/* the bio has been remapped so dispatch it */

- blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,
+ trace_block_remap(bdev_get_queue(clone->bi_bdev), clone,
tio->io->bio->bi_bdev->bd_dev,
clone->bi_sector, sector);

Index: linux-2.6-lttng/fs/bio.c
===================================================================
--- linux-2.6-lttng.orig/fs/bio.c 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/fs/bio.c 2008-10-30 10:02:04.000000000 -0400
@@ -26,6 +26,7 @@
#include <linux/mempool.h>
#include <linux/workqueue.h>
#include <linux/blktrace_api.h>
+#include <trace/block.h>
#include <scsi/sg.h> /* for struct sg_iovec */

static struct kmem_cache *bio_slab __read_mostly;
@@ -1237,7 +1238,7 @@ struct bio_pair *bio_split(struct bio *b
if (!bp)
return bp;

- blk_add_trace_pdu_int(bdev_get_queue(bi->bi_bdev), BLK_TA_SPLIT, bi,
+ trace_block_split(bdev_get_queue(bi->bi_bdev), bi,
bi->bi_sector + first_sectors);

BUG_ON(bi->bi_vcnt != 1);
Index: linux-2.6-lttng/include/linux/blktrace_api.h
===================================================================
--- linux-2.6-lttng.orig/include/linux/blktrace_api.h 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/include/linux/blktrace_api.h 2008-10-30 10:21:49.000000000 -0400
@@ -21,6 +21,8 @@ enum blktrace_cat {
BLK_TC_NOTIFY = 1 << 10, /* special message */
BLK_TC_AHEAD = 1 << 11, /* readahead */
BLK_TC_META = 1 << 12, /* metadata */
+ BLK_TC_DISCARD = 1 << 13, /* discard requests */
+ BLK_TC_DRV_DATA = 1 << 14, /* binary per-driver data */

BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
};
@@ -47,6 +49,8 @@ enum blktrace_act {
__BLK_TA_SPLIT, /* bio was split */
__BLK_TA_BOUNCE, /* bio was bounced */
__BLK_TA_REMAP, /* bio was remapped */
+ __BLK_TA_ABORT, /* request aborted */
+ __BLK_TA_DRV_DATA, /* driver-specific binary data */
};

/*
@@ -77,6 +81,8 @@ enum blktrace_notify {
#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
+#define BLK_TA_ABORT (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
+#define BLK_TA_DRV_DATA (__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))

#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
@@ -150,7 +156,6 @@ struct blk_user_trace_setup {
#if defined(CONFIG_BLK_DEV_IO_TRACE)
extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
extern void blk_trace_shutdown(struct request_queue *);
-extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
extern int do_blk_trace_setup(struct request_queue *q,
char *name, dev_t dev, struct blk_user_trace_setup *buts);
extern void __trace_note_message(struct blk_trace *, const char *fmt, ...);
@@ -176,137 +181,6 @@ extern void __trace_note_message(struct
} while (0)
#define BLK_TN_MAX_MSG 128

-/**
- * blk_add_trace_rq - Add a trace for a request oriented action
- * @q: queue the io is for
- * @rq: the source request
- * @what: the action
- *
- * Description:
- * Records an action against a request. Will log the bio offset + size.
- *
- **/
-static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
- u32 what)
-{
- struct blk_trace *bt = q->blk_trace;
- int rw = rq->cmd_flags & 0x03;
-
- if (likely(!bt))
- return;
-
- if (blk_pc_request(rq)) {
- what |= BLK_TC_ACT(BLK_TC_PC);
- __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
- } else {
- what |= BLK_TC_ACT(BLK_TC_FS);
- __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
- }
-}
-
-/**
- * blk_add_trace_bio - Add a trace for a bio oriented action
- * @q: queue the io is for
- * @bio: the source bio
- * @what: the action
- *
- * Description:
- * Records an action against a bio. Will log the bio offset + size.
- *
- **/
-static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
- u32 what)
-{
- struct blk_trace *bt = q->blk_trace;
-
- if (likely(!bt))
- return;
-
- __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
-}
-
-/**
- * blk_add_trace_generic - Add a trace for a generic action
- * @q: queue the io is for
- * @bio: the source bio
- * @rw: the data direction
- * @what: the action
- *
- * Description:
- * Records a simple trace
- *
- **/
-static inline void blk_add_trace_generic(struct request_queue *q,
- struct bio *bio, int rw, u32 what)
-{
- struct blk_trace *bt = q->blk_trace;
-
- if (likely(!bt))
- return;
-
- if (bio)
- blk_add_trace_bio(q, bio, what);
- else
- __blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
-}
-
-/**
- * blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
- * @q: queue the io is for
- * @what: the action
- * @bio: the source bio
- * @pdu: the integer payload
- *
- * Description:
- * Adds a trace with some integer payload. This might be an unplug
- * option given as the action, with the depth at unplug time given
- * as the payload
- *
- **/
-static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
- struct bio *bio, unsigned int pdu)
-{
- struct blk_trace *bt = q->blk_trace;
- __be64 rpdu = cpu_to_be64(pdu);
-
- if (likely(!bt))
- return;
-
- if (bio)
- __blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
- else
- __blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
-}
-
-/**
- * blk_add_trace_remap - Add a trace for a remap operation
- * @q: queue the io is for
- * @bio: the source bio
- * @dev: target device
- * @from: source sector
- * @to: target sector
- *
- * Description:
- * Device mapper or raid target sometimes need to split a bio because
- * it spans a stripe (or similar). Add a trace for that action.
- *
- **/
-static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
- dev_t dev, sector_t from, sector_t to)
-{
- struct blk_trace *bt = q->blk_trace;
- struct blk_io_trace_remap r;
-
- if (likely(!bt))
- return;
-
- r.device = cpu_to_be32(dev);
- r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
- r.sector = cpu_to_be64(to);
-
- __blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
-}
-
extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
char __user *arg);
extern int blk_trace_startstop(struct request_queue *q, int start);
@@ -315,11 +189,6 @@ extern int blk_trace_remove(struct reque
#else /* !CONFIG_BLK_DEV_IO_TRACE */
#define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
#define blk_trace_shutdown(q) do { } while (0)
-#define blk_add_trace_rq(q, rq, what) do { } while (0)
-#define blk_add_trace_bio(q, rq, what) do { } while (0)
-#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
-#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
-#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0)
#define do_blk_trace_setup(q, name, dev, buts) (-ENOTTY)
#define blk_trace_setup(q, name, dev, arg) (-ENOTTY)
#define blk_trace_startstop(q, start) (-ENOTTY)
Index: linux-2.6-lttng/include/trace/block.h
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-2.6-lttng/include/trace/block.h 2008-10-30 10:02:04.000000000 -0400
@@ -0,0 +1,60 @@
+#ifndef _TRACE_BLOCK_H
+#define _TRACE_BLOCK_H
+
+#include <linux/blkdev.h>
+#include <linux/tracepoint.h>
+
+DEFINE_TRACE(block_rq_abort,
+ TPPROTO(struct request_queue *q, struct request *rq),
+ TPARGS(q, rq));
+DEFINE_TRACE(block_rq_insert,
+ TPPROTO(struct request_queue *q, struct request *rq),
+ TPARGS(q, rq));
+DEFINE_TRACE(block_rq_issue,
+ TPPROTO(struct request_queue *q, struct request *rq),
+ TPARGS(q, rq));
+DEFINE_TRACE(block_rq_requeue,
+ TPPROTO(struct request_queue *q, struct request *rq),
+ TPARGS(q, rq));
+DEFINE_TRACE(block_rq_complete,
+ TPPROTO(struct request_queue *q, struct request *rq),
+ TPARGS(q, rq));
+DEFINE_TRACE(block_bio_bounce,
+ TPPROTO(struct request_queue *q, struct bio *bio),
+ TPARGS(q, bio));
+DEFINE_TRACE(block_bio_complete,
+ TPPROTO(struct request_queue *q, struct bio *bio),
+ TPARGS(q, bio));
+DEFINE_TRACE(block_bio_backmerge,
+ TPPROTO(struct request_queue *q, struct bio *bio),
+ TPARGS(q, bio));
+DEFINE_TRACE(block_bio_frontmerge,
+ TPPROTO(struct request_queue *q, struct bio *bio),
+ TPARGS(q, bio));
+DEFINE_TRACE(block_bio_queue,
+ TPPROTO(struct request_queue *q, struct bio *bio),
+ TPARGS(q, bio));
+DEFINE_TRACE(block_getrq,
+ TPPROTO(struct request_queue *q, struct bio *bio, int rw),
+ TPARGS(q, bio, rw));
+DEFINE_TRACE(block_sleeprq,
+ TPPROTO(struct request_queue *q, struct bio *bio, int rw),
+ TPARGS(q, bio, rw));
+DEFINE_TRACE(block_plug,
+ TPPROTO(struct request_queue *q),
+ TPARGS(q));
+DEFINE_TRACE(block_unplug_timer,
+ TPPROTO(struct request_queue *q),
+ TPARGS(q));
+DEFINE_TRACE(block_unplug_io,
+ TPPROTO(struct request_queue *q),
+ TPARGS(q));
+DEFINE_TRACE(block_split,
+ TPPROTO(struct request_queue *q, struct bio *bio, unsigned int pdu),
+ TPARGS(q, bio, pdu));
+DEFINE_TRACE(block_remap,
+ TPPROTO(struct request_queue *q, struct bio *bio, dev_t dev,
+ sector_t from, sector_t to),
+ TPARGS(q, bio, dev, from, to));
+
+#endif
Index: linux-2.6-lttng/mm/bounce.c
===================================================================
--- linux-2.6-lttng.orig/mm/bounce.c 2008-10-30 10:01:12.000000000 -0400
+++ linux-2.6-lttng/mm/bounce.c 2008-10-30 10:02:04.000000000 -0400
@@ -14,6 +14,7 @@
#include <linux/hash.h>
#include <linux/highmem.h>
#include <linux/blktrace_api.h>
+#include <trace/block.h>
#include <asm/tlbflush.h>

#define POOL_SIZE 64
@@ -222,7 +223,7 @@ static void __blk_queue_bounce(struct re
if (!bio)
return;

- blk_add_trace_bio(q, *bio_orig, BLK_TA_BOUNCE);
+ trace_block_bio_bounce(q, *bio_orig);

/*
* at least one page was bounced, fill in possible non-highmem

--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
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