From 10baa26c8ccba6f100397c9ba6534be175762e8d Mon Sep 17 00:00:00 2001 From: Andre Detsch Date: Tue, 21 Oct 2008 11:15:23 +1100 Subject: [PATCH] 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 Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/sched.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 67595bc380dc..6253df5a436e 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);