Patchwork [07/18] powerpc/spufs: Allow gang to grow in size after it has been started

login
register
mail settings
Submitter Andre Detsch
Date Dec. 10, 2008, 7:40 p.m.
Message ID <200812101740.53135.adetsch@br.ibm.com>
Download mbox | patch
Permalink /patch/13322/
State RFC
Headers show

Comments

Andre Detsch - Dec. 10, 2008, 7:40 p.m.
Just deactivate it, add the new context, and let the calling thread
drives its reactivation.  It needs to be unscheduled, since it may
no longer fit or it may need to be migrated to a different node.

Signed-off-by: Luke Browning <lukebrowning@us.ibm.com>
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
---
 arch/powerpc/platforms/cell/spufs/context.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

Patch

diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c
index b810050..d3887fe 100644
--- a/arch/powerpc/platforms/cell/spufs/context.c
+++ b/arch/powerpc/platforms/cell/spufs/context.c
@@ -57,6 +57,17 @@  struct spu_context *alloc_spu_context(struct spu_gang *gang)
 	if (spu_init_csa(&ctx->csa))
 		goto out_free_gang;
 
+	/* If the gang is running, it needs to be stopped, since we have a
+	 * new context that needs to be gang scheduled.  Gangs are allowed
+	 * to grow and shrink over time, but they are unscheduled when it
+	 * happens as the gang may need to migrated to a different node.
+	 */
+	if (atomic_read(&gang->nstarted)) {
+		mutex_lock(&gang->mutex);
+		spu_deactivate(gang);
+		mutex_unlock(&gang->mutex);
+	}
+
 	spin_lock_init(&ctx->mmio_lock);
 	mutex_init(&ctx->mapping_lock);
 	kref_init(&ctx->kref);