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authorAndre Detsch <adetsch@br.ibm.com>2008-10-21 11:15:23 +1100
committerJeremy Kerr <jk@ozlabs.org>2008-10-21 11:15:23 +1100
commit10baa26c8ccba6f100397c9ba6534be175762e8d (patch)
treea909c5246f40932848858c8ed72894fd58732fb1
parent837ef884b702edd1c4514eaed1dbecd48721bd22 (diff)
powerpc/spufs: Improve search of node for contexts with SPU affinity
This patch improves redability of the code responsible for trying to find a node with enough SPUs not committed to other affinity gangs. An additional check is also added, to avoid taking into account gangs that have no SPU affinity. Signed-off-by: Andre Detsch <adetsch@br.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
-rw-r--r--arch/powerpc/platforms/cell/spufs/sched.c19
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 67595bc380d..6253df5a436 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -312,6 +312,15 @@ static struct spu *aff_ref_location(struct spu_context *ctx, int mem_aff,
*/
node = cpu_to_node(raw_smp_processor_id());
for (n = 0; n < MAX_NUMNODES; n++, node++) {
+ /*
+ * "available_spus" counts how many spus are not potentially
+ * going to be used by other affinity gangs whose reference
+ * context is already in place. Although this code seeks to
+ * avoid having affinity gangs with a summed amount of
+ * contexts bigger than the amount of spus in the node,
+ * this may happen sporadically. In this case, available_spus
+ * becomes negative, which is harmless.
+ */
int available_spus;
node = (node < MAX_NUMNODES) ? node : 0;
@@ -321,12 +330,10 @@ static struct spu *aff_ref_location(struct spu_context *ctx, int mem_aff,
available_spus = 0;
mutex_lock(&cbe_spu_info[node].list_mutex);
list_for_each_entry(spu, &cbe_spu_info[node].spus, cbe_list) {
- if (spu->ctx && spu->ctx->gang
- && spu->ctx->aff_offset == 0)
- available_spus -=
- (spu->ctx->gang->contexts - 1);
- else
- available_spus++;
+ if (spu->ctx && spu->ctx->gang && !spu->ctx->aff_offset
+ && spu->ctx->gang->aff_ref_spu)
+ available_spus -= spu->ctx->gang->contexts;
+ available_spus++;
}
if (available_spus < ctx->gang->contexts) {
mutex_unlock(&cbe_spu_info[node].list_mutex);