Patchwork [06/18] powerpc/spufs: Time slice lazily loaded contexts

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Submitter Andre Detsch
Date Dec. 10, 2008, 7:40 p.m.
Message ID <200812101740.54125.adetsch@br.ibm.com>
Download mbox | patch
Permalink /patch/13324/
State RFC
Headers show

Comments

Andre Detsch - Dec. 10, 2008, 7:40 p.m.
All SPUs are stopped.  All contexts are either executing library
code or they have major faulted in spu_run.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
---
 arch/powerpc/platforms/cell/spufs/sched.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

Patch

diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 3c83bd3..acd584e 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -1244,9 +1244,13 @@  static noinline int spusched_tick(struct spu_gang *gang,
 		goto out;
 
 	/*
-	 * If nrunnable is zero, then all of the contexts are in user mode.
+	 * If nrunnable is zero, then all of the contexts are in user mode
+	 * and by definition nfaulting is equal to zero.  Otherwise if they
+	 * are equal, all of the contexts in spu_run have faulted.  In both
+	 * cases, all spus are stopped and we should yield assuming there
+	 * is another gang on the runqueue.
 	 */
-	yield = !atomic_read(&gang->nrunnable);
+	yield = atomic_read(&gang->nrunnable) == atomic_read(&gang->nfaulting);
 
 	if (yield || ((ctx->policy != SCHED_FIFO) && (!--ctx->time_slice))) {
 		if (spu_prio->nr_waiting) {