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* [merged] drivers-tty-compute-current-directly.patch removed from -mm tree
@ 2017-01-19 19:23 akpm
  0 siblings, 0 replies; only message in thread
From: akpm @ 2017-01-19 19:23 UTC (permalink / raw)
  To: dave, gregkh, mark.rutland, mingo, peterz, mm-commits


The patch titled
     Subject: drivers/tty: compute current directly
has been removed from the -mm tree.  Its filename was
     drivers-tty-compute-current-directly.patch

This patch was dropped because it was merged into mainline or a subsystem tree

------------------------------------------------------
From: Davidlohr Bueso <dave@stgolabs.net>
Subject: drivers/tty: compute current directly

This patch effectively replaces the tsk pointer dereference (which is
obviously == current), to directly use get_current() macro.  This is to
make the removal of setting foreign task states smoother and painfully
obvious.  Performance win on some archs such as x86-64 and ppc64 -- arm64
is no longer an issue:

    https://lkml.org/lkml/2016/12/30/230

Link: http://lkml.kernel.org/r/1483479794-14013-3-git-send-email-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/tty/tty_ldsem.c |   18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff -puN drivers/tty/tty_ldsem.c~drivers-tty-compute-current-directly drivers/tty/tty_ldsem.c
--- a/drivers/tty/tty_ldsem.c~drivers-tty-compute-current-directly
+++ a/drivers/tty/tty_ldsem.c
@@ -200,7 +200,6 @@ static struct ld_semaphore __sched *
 down_read_failed(struct ld_semaphore *sem, long count, long timeout)
 {
 	struct ldsem_waiter waiter;
-	struct task_struct *tsk = current;
 	long adjust = -LDSEM_ACTIVE_BIAS + LDSEM_WAIT_BIAS;
 
 	/* set up my own style of waitqueue */
@@ -221,8 +220,8 @@ down_read_failed(struct ld_semaphore *se
 	list_add_tail(&waiter.list, &sem->read_wait);
 	sem->wait_readers++;
 
-	waiter.task = tsk;
-	get_task_struct(tsk);
+	waiter.task = current;
+	get_task_struct(current);
 
 	/* if there are no active locks, wake the new lock owner(s) */
 	if ((count & LDSEM_ACTIVE_MASK) == 0)
@@ -232,7 +231,7 @@ down_read_failed(struct ld_semaphore *se
 
 	/* wait to be given the lock */
 	for (;;) {
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+		set_task_state(current, TASK_UNINTERRUPTIBLE);
 
 		if (!waiter.task)
 			break;
@@ -241,7 +240,7 @@ down_read_failed(struct ld_semaphore *se
 		timeout = schedule_timeout(timeout);
 	}
 
-	__set_task_state(tsk, TASK_RUNNING);
+	__set_task_state(current, TASK_RUNNING);
 
 	if (!timeout) {
 		/* lock timed out but check if this task was just
@@ -268,7 +267,6 @@ static struct ld_semaphore __sched *
 down_write_failed(struct ld_semaphore *sem, long count, long timeout)
 {
 	struct ldsem_waiter waiter;
-	struct task_struct *tsk = current;
 	long adjust = -LDSEM_ACTIVE_BIAS;
 	int locked = 0;
 
@@ -289,16 +287,16 @@ down_write_failed(struct ld_semaphore *s
 
 	list_add_tail(&waiter.list, &sem->write_wait);
 
-	waiter.task = tsk;
+	waiter.task = current;
 
-	set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+	set_task_state(current, TASK_UNINTERRUPTIBLE);
 	for (;;) {
 		if (!timeout)
 			break;
 		raw_spin_unlock_irq(&sem->wait_lock);
 		timeout = schedule_timeout(timeout);
 		raw_spin_lock_irq(&sem->wait_lock);
-		set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+		set_task_state(current, TASK_UNINTERRUPTIBLE);
 		locked = writer_trylock(sem);
 		if (locked)
 			break;
@@ -309,7 +307,7 @@ down_write_failed(struct ld_semaphore *s
 	list_del(&waiter.list);
 	raw_spin_unlock_irq(&sem->wait_lock);
 
-	__set_task_state(tsk, TASK_RUNNING);
+	__set_task_state(current, TASK_RUNNING);
 
 	/* lock wait may have timed out */
 	if (!locked)
_

Patches currently in -mm which might be from dave@stgolabs.net are

m32r-use-generic-currenth.patch
mmcompaction-serialize-waitqueue_active-checks.patch


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2017-01-19 19:23 [merged] drivers-tty-compute-current-directly.patch removed from -mm tree akpm

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