[PATCH 0/3 v2] [GIT PULL] remove unlikelys

[PATCH 0/3 v2] [GIT PULL] remove unlikelys

[Steven Rostedt]

Ingo,

The differences between v1 and v2 is that I only included the non
controversial patches. I also modified the change log of pre_schedule_rt
to include the annotated branch profiler output.

I just did a force push, so please use ssh, or verify that only these
three patches are present.

Thanks,

-- Steve

Please pull the latest annotate-branch/cleanups tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace.git
annotate-branch/cleanups


Steven Rostedt (3):
      sched: remove unlikely in pre_schedule_rt
      sched: remove unlikelys from sched_move_task
      mm: remove unlikelys for unlock in rmap.c

----
 kernel/sched.c    |    4 ++--
 kernel/sched_rt.c |    2 +-
 mm/rmap.c         |    8 ++++----
 3 files changed, 7 insertions(+), 7 deletions(-)
-- 

[PATCH 1/3 v2] sched: remove unlikely in pre_schedule_rt

[Steven Rostedt]

[-- Attachment #1: 0001-sched-remove-unlikely-in-pre_schedule_rt.patch --]
[-- Type: text/plain, Size: 1309 bytes --]

From: Steven Rostedt <rostedt@goodmis.org>

Impact: clean up

The annotated branch profiler shows that the unlikely used by
pre_schedule_rt is always incorrect. This makes sense because in
sched.c we have:

	if (prev->sched_class->pre_schedule)
		prev->sched_class->pre_schedule(rq, prev);

And we are saying that prev is unlikely to be an rt task. This looks
more like a likely candidate to me.

Here's the annotated branch profiler output:

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0     4244 100 pre_schedule_rt                sched_rt.c           1263

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 kernel/sched_rt.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index bac1061..537af77 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -1260,7 +1260,7 @@ static int pull_rt_task(struct rq *this_rq)
 static void pre_schedule_rt(struct rq *rq, struct task_struct *prev)
 {
 	/* Try to pull RT tasks here if we lower this rq's prio */
-	if (unlikely(rt_task(prev)) && rq->rt.highest_prio > prev->prio)
+	if (rt_task(prev) && rq->rt.highest_prio > prev->prio)
 		pull_rt_task(rq);
 }
 
-- 
1.6.2

-- 

[PATCH 2/3 v2] sched: remove unlikelys from sched_move_task

[Steven Rostedt]

[-- Attachment #1: 0002-sched-remove-unlikelys-from-sched_move_task.patch --]
[-- Type: text/plain, Size: 1260 bytes --]

From: Steven Rostedt <rostedt@goodmis.org>

Impact: clean up

We seem to be moving running tasks more than non running tasks.
I guess tasks like to move themselves.

These are also candidates for likely:

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0    10027 100 sched_move_task                sched.c              8918
       0    10027 100 sched_move_task                sched.c              8908

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 kernel/sched.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 8e2558c..5a60745 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -8905,7 +8905,7 @@ void sched_move_task(struct task_struct *tsk)
 
 	if (on_rq)
 		dequeue_task(rq, tsk, 0);
-	if (unlikely(running))
+	if (running)
 		tsk->sched_class->put_prev_task(rq, tsk);
 
 	set_task_rq(tsk, task_cpu(tsk));
@@ -8915,7 +8915,7 @@ void sched_move_task(struct task_struct *tsk)
 		tsk->sched_class->moved_group(tsk);
 #endif
 
-	if (unlikely(running))
+	if (running)
 		tsk->sched_class->set_curr_task(rq);
 	if (on_rq)
 		enqueue_task(rq, tsk, 0);
-- 
1.6.2

-- 

[PATCH 3/3 v2] mm: remove unlikelys for unlock in rmap.c

[Steven Rostedt]

[-- Attachment #1: 0003-mm-remove-unlikelys-for-unlock-in-rmap.c.patch --]
[-- Type: text/plain, Size: 2157 bytes --]

From: Steven Rostedt <rostedt@goodmis.org>

Impact: clean up

The annotated branch profiler shows that the rmap calls are likely
called with unlock set.

 correct incorrect  %        Function                  File              Line
 ------- ---------  -        --------                  ----              ----
       0    46100 100 try_to_unmap_anon              rmap.c               1013
       0    46100 100 try_to_unmap_anon              rmap.c               1005
       0     5763 100 try_to_unmap_file              rmap.c               1074
       0     5763 100 try_to_unmap_file              rmap.c               1069

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
---
 mm/rmap.c |    8 ++++----
 1 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index 1652166..ad62fe0 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1002,7 +1002,7 @@ static int try_to_unmap_anon(struct page *page, int unlock, int migration)
 	unsigned int mlocked = 0;
 	int ret = SWAP_AGAIN;
 
-	if (MLOCK_PAGES && unlikely(unlock))
+	if (MLOCK_PAGES && unlock)
 		ret = SWAP_SUCCESS;	/* default for try_to_munlock() */
 
 	anon_vma = page_lock_anon_vma(page);
@@ -1010,7 +1010,7 @@ static int try_to_unmap_anon(struct page *page, int unlock, int migration)
 		return ret;
 
 	list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
-		if (MLOCK_PAGES && unlikely(unlock)) {
+		if (MLOCK_PAGES && unlock) {
 			if (!((vma->vm_flags & VM_LOCKED) &&
 			      page_mapped_in_vma(page, vma)))
 				continue;  /* must visit all unlocked vmas */
@@ -1066,12 +1066,12 @@ static int try_to_unmap_file(struct page *page, int unlock, int migration)
 	unsigned int mapcount;
 	unsigned int mlocked = 0;
 
-	if (MLOCK_PAGES && unlikely(unlock))
+	if (MLOCK_PAGES && unlock)
 		ret = SWAP_SUCCESS;	/* default for try_to_munlock() */
 
 	spin_lock(&mapping->i_mmap_lock);
 	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
-		if (MLOCK_PAGES && unlikely(unlock)) {
+		if (MLOCK_PAGES && unlock) {
 			if (!((vma->vm_flags & VM_LOCKED) &&
 						page_mapped_in_vma(page, vma)))
 				continue;	/* must visit all vmas */
-- 
1.6.2

-- 

Re: [PATCH 0/3 v2] [GIT PULL] remove unlikelys

[Steven Rostedt]

On Wed, 25 Mar 2009, Steven Rostedt wrote:
> 
> I just did a force push, so please use ssh, or verify that only these
> three patches are present.

Here's the HEAD SHA1:

   79210dd022b4d7f6f75aeb7d508a3f75fabaae4c

-- Steve

Re: [PATCH 0/3 v2] [GIT PULL] remove unlikelys

[Ingo Molnar]

* Steven Rostedt <rostedt@goodmis.org> wrote:

> Ingo,
> 
> The differences between v1 and v2 is that I only included the non 
> controversial patches. I also modified the change log of 
> pre_schedule_rt to include the annotated branch profiler output.

>       mm: remove unlikelys for unlock in rmap.c

>  mm/rmap.c         |    8 ++++----

the rmap.c thing looks uncontroversial to me, but an MM person 
should still have a look and Ack it.

	Ingo