Commit 0855b543 authored by Andre Detsch's avatar Andre Detsch Committed by Jeremy Kerr
Browse files

powerpc/spufs: fix aff_mutex and cbe_spu_info[n].list_mutex deadlock



Currenlt,, it is possible to lock aff_mutex and
cbe_spu_info[n].list_mutex in different orders, allowing a deadlock to
occur. With this change, aff_mutex is not taken within a list_mutex
critical section anymore.
Signed-off-by: default avatarAndre Detsch <adetsch@br.ibm.com>
Signed-off-by: default avatarJeremy Kerr <jk@ozlabs.org>
parent 9bcab840
......@@ -389,6 +389,9 @@ static int has_affinity(struct spu_context *ctx)
if (list_empty(&ctx->aff_list))
return 0;
if (atomic_read(&ctx->gang->aff_sched_count) == 0)
ctx->gang->aff_ref_spu = NULL;
if (!gang->aff_ref_spu) {
if (!(gang->aff_flags & AFF_MERGED))
aff_merge_remaining_ctxs(gang);
......@@ -416,14 +419,8 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
if (spu->ctx->flags & SPU_CREATE_NOSCHED)
atomic_dec(&cbe_spu_info[spu->node].reserved_spus);
if (ctx->gang){
mutex_lock(&ctx->gang->aff_mutex);
if (has_affinity(ctx)) {
if (atomic_dec_and_test(&ctx->gang->aff_sched_count))
ctx->gang->aff_ref_spu = NULL;
}
mutex_unlock(&ctx->gang->aff_mutex);
}
if (ctx->gang)
atomic_dec_if_positive(&ctx->gang->aff_sched_count);
spu_switch_notify(spu, NULL);
spu_unmap_mappings(ctx);
......@@ -562,10 +559,7 @@ static struct spu *spu_get_idle(struct spu_context *ctx)
goto found;
mutex_unlock(&cbe_spu_info[node].list_mutex);
mutex_lock(&ctx->gang->aff_mutex);
if (atomic_dec_and_test(&ctx->gang->aff_sched_count))
ctx->gang->aff_ref_spu = NULL;
mutex_unlock(&ctx->gang->aff_mutex);
atomic_dec(&ctx->gang->aff_sched_count);
goto not_found;
}
mutex_unlock(&ctx->gang->aff_mutex);
......
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