From d3d9d2a5ea9770db07aeb13a07f999aa48e8f865 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Mon, 4 Dec 2006 09:27:41 +0100
Subject: [PATCH 1/2] [PATCH] blktrace: uninline trace_note()
It's too large to inline. Additionally clean it up, by fast pathing
the likely path.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
block/blktrace.c | 30 +++++++++++++++---------------
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/block/blktrace.c b/block/blktrace.c
index 562ca7cbf858b..17bbdb811aa75 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -31,25 +31,25 @@ static unsigned int blktrace_seq __read_mostly = 1;
/*
* Send out a notify message.
*/
-static inline unsigned int trace_note(struct blk_trace *bt,
- pid_t pid, int action,
- const void *data, size_t len)
+static unsigned int trace_note(struct blk_trace *bt, pid_t pid, int action,
+ const void *data, size_t len)
{
struct blk_io_trace *t;
- int cpu = smp_processor_id();
t = relay_reserve(bt->rchan, sizeof(*t) + len);
- if (t == NULL)
- return 0;
-
- 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 = action;
- t->pid = pid;
- t->cpu = cpu;
- t->pdu_len = len;
- memcpy((void *) t + sizeof(*t), data, 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 = action;
+ t->pid = pid;
+ t->cpu = cpu;
+ t->pdu_len = len;
+ memcpy((void *) t + sizeof(*t), data, len);
+ }
+
return blktrace_seq;
}
From a863055b1066be1b8e1107f71be01daeed6bde31 Mon Sep 17 00:00:00 2001
From: Jens Axboe <jens.axboe@oracle.com>
Date: Mon, 4 Dec 2006 09:30:58 +0100
Subject: [PATCH 2/2] [PATCH] blktrace: don't return blktrace_seq from
trace_note()
Only the process notifier needs it, and it can set it manually.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
block/blktrace.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/block/blktrace.c b/block/blktrace.c
index 17bbdb811aa75..74e02c04b2dab 100644
--- a/block/blktrace.c
+++ b/block/blktrace.c
@@ -31,8 +31,8 @@ static unsigned int blktrace_seq __read_mostly = 1;
/*
* Send out a notify message.
*/
-static unsigned int trace_note(struct blk_trace *bt, pid_t pid, int action,
- const void *data, size_t len)
+static void trace_note(struct blk_trace *bt, pid_t pid, int action,
+ const void *data, size_t len)
{
struct blk_io_trace *t;
@@ -49,8 +49,6 @@ static unsigned int trace_note(struct blk_trace *bt, pid_t pid, int action,
t->pdu_len = len;
memcpy((void *) t + sizeof(*t), data, len);
}
-
- return blktrace_seq;
}
/*
@@ -59,9 +57,8 @@ static unsigned int trace_note(struct blk_trace *bt, pid_t pid, int action,
*/
static void trace_note_tsk(struct blk_trace *bt, struct task_struct *tsk)
{
- tsk->btrace_seq = trace_note(bt, tsk->pid,
- BLK_TN_PROCESS,
- tsk->comm, sizeof(tsk->comm));
+ 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)