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| author | Andre Detsch <adetsch@br.ibm.com> | 2008-07-24 10:57:26 +1000 |
|---|---|---|
| committer | Jeremy Kerr <jk@ozlabs.org> | 2008-07-24 10:57:26 +1000 |
| commit | 0855b543222e79cbbd9d66dd56cb54740e7d524f (patch) | |
| tree | 77e6e838138d623c96e61c497417e9fc0f82100e /arch/powerpc | |
| parent | 9bcab8405c98c34849c5795c717b7e6a3e2d3875 (diff) | |
| download | blackbird-op-linux-0855b543222e79cbbd9d66dd56cb54740e7d524f.tar.gz blackbird-op-linux-0855b543222e79cbbd9d66dd56cb54740e7d524f.zip | |
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: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/sched.c | 18 |
1 files changed, 6 insertions, 12 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 34654743363d..f293963cd855 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -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); |
