Very Computer

by **Paul P Komkoff J** » Mon, 08 Apr 2002 07:30:22

This is the pilot of task->state cleanup in 2.4.x. Feel free to blame me for
incorrect use of set_task_state vs. __set_task_state

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.310 -> 1.311
# drivers/char/drm-4.0/radeon_drv.c 1.1 -> 1.2
# drivers/char/drm-4.0/tdfx_drv.c 1.1 -> 1.2
# drivers/char/drm/drm_lock.h 1.2 -> 1.3
# drivers/char/drm-4.0/i810_drv.c 1.1 -> 1.2
# drivers/char/drm-4.0/lists.c 1.1 -> 1.2
# drivers/char/drm/drm_drv.h 1.3 -> 1.4
# drivers/char/drm/drm_lists.h 1.2 -> 1.3
# drivers/char/drm/i810_dma.c 1.6 -> 1.7
# drivers/char/drm-4.0/r128_drv.c 1.1 -> 1.2
# drivers/char/drm-4.0/gamma_dma.c 1.1 -> 1.2
# drivers/char/drm-4.0/mga_dma.c 1.1 -> 1.2
# drivers/char/drm-4.0/dma.c 1.1 -> 1.2
# drivers/char/drm-4.0/i810_dma.c 1.2 -> 1.3
# drivers/char/drm-4.0/ffb_drv.c 1.2 -> 1.3
# drivers/char/drm/drm_dma.h 1.3 -> 1.4
# drivers/char/drm-4.0/lock.c 1.1 -> 1.2
# drivers/char/drm-4.0/mga_drv.c 1.1 -> 1.2
# drivers/char/drm/gamma_dma.c 1.2 -> 1.3
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/04/07 sting...@stingr.net 1.311
# task->state cleanup part 1
# --------------------------------------------
#
diff -Nru a/drivers/char/drm/drm_dma.h b/drivers/char/drm/drm_dma.h
--- a/drivers/char/drm/drm_dma.h Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/drm_dma.h Sun Apr 7 02:02:35 2002
@@ -359,7 +359,7 @@
add_wait_queue(&q->write_queue, &entry);
atomic_inc(&q->block_count);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!atomic_read(&q->block_write)) break;
schedule();
if (signal_pending(current)) {
@@ -369,7 +369,7 @@
}
}
atomic_dec(&q->block_count);
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&q->write_queue, &entry);
}

diff -Nru a/drivers/char/drm/drm_drv.h b/drivers/char/drm/drm_drv.h
--- a/drivers/char/drm/drm_drv.h Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/drm_drv.h Sun Apr 7 02:02:35 2002
@@ -790,7 +790,7 @@
DECLARE_WAITQUEUE( entry, current );
add_wait_queue( &dev->lock.lock_queue, &entry );
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if ( !dev->lock.hw_lock ) {
/* Device has been unregistered */
retcode = -EINTR;
@@ -813,7 +813,7 @@
break;
}
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue( &dev->lock.lock_queue, &entry );
if( !retcode ) {
DRIVER_RELEASE();
@@ -962,7 +962,7 @@
if ( !ret ) {
add_wait_queue( &dev->lock.lock_queue, &entry );
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if ( !dev->lock.hw_lock ) {
/* Device has been unregistered */
ret = -EINTR;
@@ -983,7 +983,7 @@
break;
}
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue( &dev->lock.lock_queue, &entry );
}

diff -Nru a/drivers/char/drm/drm_lists.h b/drivers/char/drm/drm_lists.h
--- a/drivers/char/drm/drm_lists.h Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/drm_lists.h Sun Apr 7 02:02:35 2002
@@ -212,13 +212,13 @@
if (block) {
add_wait_queue(&bl->waiting, &entry);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!atomic_read(&bl->wfh)
&& (buf = DRM(freelist_try)(bl))) break;
schedule();
if (signal_pending(current)) break;
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&bl->waiting, &entry);
}
return buf;
diff -Nru a/drivers/char/drm/drm_lock.h b/drivers/char/drm/drm_lock.h
--- a/drivers/char/drm/drm_lock.h Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/drm_lock.h Sun Apr 7 02:02:35 2002
@@ -125,7 +125,7 @@
add_wait_queue(&q->flush_queue, &entry);
atomic_inc(&q->block_count);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!DRM_BUFCOUNT(&q->waitlist)) break;
schedule();
if (signal_pending(current)) {
@@ -134,7 +134,7 @@
}
}
atomic_dec(&q->block_count);
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&q->flush_queue, &entry);
}
atomic_dec(&q->use_count);
diff -Nru a/drivers/char/drm/gamma_dma.c b/drivers/char/drm/gamma_dma.c
--- a/drivers/char/drm/gamma_dma.c Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/gamma_dma.c Sun Apr 7 02:02:35 2002
@@ -428,7 +428,7 @@
&& !(dev->queuelist[buf->context]->flags
& _DRM_CONTEXT_PRESERVED)) {
add_wait_queue(&dev->context_wait, &entry);
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
/* PRE: dev->last_context != buf->context */
DRM(context_switch)(dev, dev->last_context,
buf->context);
@@ -438,7 +438,7 @@
NOTE WE HOLD THE LOCK THROUGHOUT THIS
TIME! */
schedule();
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&dev->context_wait, &entry);
if (signal_pending(current)) {
retcode = -EINTR;
@@ -505,7 +505,7 @@
if (d->flags & _DRM_DMA_BLOCK) {
DRM_DEBUG("%d waiting\n", current->pid);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!last_buf->waiting && !last_buf->pending)
break; /* finished */
schedule();
@@ -514,7 +514,7 @@
break;
}
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
DRM_DEBUG("%d running\n", current->pid);
remove_wait_queue(&last_buf->dma_wait, &entry);
if (!retcode
diff -Nru a/drivers/char/drm/i810_dma.c b/drivers/char/drm/i810_dma.c
--- a/drivers/char/drm/i810_dma.c Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm/i810_dma.c Sun Apr 7 02:02:35 2002
@@ -975,7 +975,7 @@
end = jiffies + (HZ*3);

for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
i810_dma_quiescent_emit(dev);
if (atomic_read(&dev_priv->flush_done) == 1) break;
if((signed)(end - jiffies) <= 0) {
@@ -988,7 +988,7 @@
}
}

- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&dev_priv->flush_queue, &entry);

return;
@@ -1009,7 +1009,7 @@
add_wait_queue(&dev_priv->flush_queue, &entry);
end = jiffies + (HZ*3);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
i810_dma_emit_flush(dev);
if (atomic_read(&dev_priv->flush_done) == 1) break;
if((signed)(end - jiffies) <= 0) {
@@ -1023,7 +1023,7 @@
}
}

- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&dev_priv->flush_queue, &entry);

diff -Nru a/drivers/char/drm-4.0/dma.c b/drivers/char/drm-4.0/dma.c
--- a/drivers/char/drm-4.0/dma.c Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm-4.0/dma.c Sun Apr 7 02:02:35 2002
@@ -403,7 +403,7 @@
add_wait_queue(&q->write_queue, &entry);
atomic_inc(&q->block_count);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!atomic_read(&q->block_write)) break;
schedule();
if (signal_pending(current)) {
@@ -413,7 +413,7 @@
}
}
atomic_dec(&q->block_count);
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&q->write_queue, &entry);
}

diff -Nru a/drivers/char/drm-4.0/ffb_drv.c b/drivers/char/drm-4.0/ffb_drv.c
--- a/drivers/char/drm-4.0/ffb_drv.c Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm-4.0/ffb_drv.c Sun Apr 7 02:02:35 2002
@@ -709,7 +709,7 @@

/* Contention */
atomic_inc(&dev->total_sleeps);
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
current->policy |= SCHED_YIELD;
schedule();
if (signal_pending(current)) {
@@ -717,7 +717,7 @@
break;
}
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&dev->lock.lock_queue, &entry);

if (!ret) {
diff -Nru a/drivers/char/drm-4.0/gamma_dma.c b/drivers/char/drm-4.0/gamma_dma.c
--- a/drivers/char/drm-4.0/gamma_dma.c Sun Apr 7 02:02:35 2002
+++ b/drivers/char/drm-4.0/gamma_dma.c Sun Apr 7 02:02:35 2002
@@ -466,7 +466,7 @@
&& !(dev->queuelist[buf->context]->flags
& _DRM_CONTEXT_PRESERVED)) {
add_wait_queue(&dev->context_wait, &entry);
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
/* PRE: dev->last_context != buf->context */
drm_context_switch(dev, dev->last_context,
buf->context);
@@ -476,7 +476,7 @@
NOTE WE HOLD THE LOCK THROUGHOUT THIS
TIME! */
schedule();
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
remove_wait_queue(&dev->context_wait, &entry);
if (signal_pending(current)) {
retcode = -EINTR;
@@ -543,7 +543,7 @@
if (d->flags & _DRM_DMA_BLOCK) {
DRM_DEBUG("%d waiting\n", current->pid);
for (;;) {
- current->state = TASK_INTERRUPTIBLE;
+ set_current_state(TASK_INTERRUPTIBLE);
if (!last_buf->waiting && !last_buf->pending)
break; /* finished */
schedule();
@@ -552,7 +552,7 @@
break;
}
}
- current->state = TASK_RUNNING;
+ set_current_state(TASK_RUNNING);
...

read more »

by **Robert Lov** » Mon, 08 Apr 2002 08:50:07

Quote:> This is the pilot of task->state cleanup in 2.4.x. Feel free to blame me for
> incorrect use of set_task_state vs. __set_task_state

Nice cleanup. Awful lot of [items] in the subject though :)

You don't have to worry about your choices wrt set_current_state vs
__set_current_state - by using only set_current_state you erred on the
side of caution. set_current_state enforces a memory barrier around the
write on SMP (on UP it is the same code) while __set_current_state does
not.

If anyone can verify where it is safe in this code to use
__set_current_state instead, speak up so Paul can make the micro
optimization accordingly.

Robert Love

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by **John Levo** » Mon, 08 Apr 2002 20:10:08

> If anyone can verify where it is safe in this code to use
> __set_current_state instead, speak up so Paul can make the micro
> optimization accordingly.

Ugh, please don't. There is enough mystery as to which one is safe to
use when already.

Is there really a circumstance where avoiding the mb makes a noticable
difference (in driver code, core code is something else ...) ?

john

--
"I never understood what's so hard about picking a unique
first and last name - and not going beyond the 6 character limit."
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Very Computer

[RFC][PATCH][CLEANUP] task->state cleanup: pilot

[RFC][PATCH][CLEANUP] task->state cleanup: pilot

[RFC][PATCH][CLEANUP] task->state cleanup: pilot

[RFC][PATCH][CLEANUP] task->state cleanup: pilot