From 0111a701867a796a7ca6ecbc385e4befc9f35066 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Wed, 27 Feb 2008 19:08:13 +1100 Subject: [POWERPC] spufs: fix invalid scheduling of forgotten contexts At present, we have a situation where a context with no owner is re-scheduled by spu_forget: Thread 1: reading regs file Thread 2: context owner spu_forget() - ctx->owner = NULL - set SPU_SCHED_WAS_ACTIVE spu_acquire_saved() - context is in saved state spu_release_saved() - SPU_SCHED_WAS_ACTIVE is set, so spu_activate() the context, which now has no owner In spu_forget(), we shouldn't be requesting a re-schedule by setting SPU_SCHED_WAS_ACTIVE. This change removes the set_bit in spu_forget(), so that spu_release_saved() doesn't reinsert this destroyed context on to the run queue. Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/context.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) (limited to 'arch/powerpc/platforms/cell/spufs/context.c') diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c index 133995ed5cc..cf6c2c89211 100644 --- a/arch/powerpc/platforms/cell/spufs/context.c +++ b/arch/powerpc/platforms/cell/spufs/context.c @@ -109,13 +109,12 @@ void spu_forget(struct spu_context *ctx) /* * This is basically an open-coded spu_acquire_saved, except that - * we don't acquire the state mutex interruptible. + * we don't acquire the state mutex interruptible, and we don't + * want this context to be rescheduled on release. */ mutex_lock(&ctx->state_mutex); - if (ctx->state != SPU_STATE_SAVED) { - set_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags); + if (ctx->state != SPU_STATE_SAVED) spu_deactivate(ctx); - } mm = ctx->owner; ctx->owner = NULL; -- cgit v1.2.3 From c368392a9951e6e25e2e2f9268153f1e9365e2c2 Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 11 Mar 2008 12:46:18 +1100 Subject: [POWERPC] spufs: fix rescheduling of non-runnable contexts At present, we can hit the BUG_ON in __spu_update_sched_info by reading the regs file of a context between two calls to spu_run. The spu_release_saved called by spufs_regs_read() is resulting in the (now non-runnable) context being placed back on the run queue, so the next call to spu_run ends up in the bug condition. This change uses the SPU_SCHED_SPU_RUN flag to only reschedule a context if it's still in spu_run(). Signed-off-by: Jeremy Kerr --- arch/powerpc/platforms/cell/spufs/context.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/powerpc/platforms/cell/spufs/context.c') diff --git a/arch/powerpc/platforms/cell/spufs/context.c b/arch/powerpc/platforms/cell/spufs/context.c index cf6c2c89211..0ad83aeb70b 100644 --- a/arch/powerpc/platforms/cell/spufs/context.c +++ b/arch/powerpc/platforms/cell/spufs/context.c @@ -170,7 +170,8 @@ void spu_release_saved(struct spu_context *ctx) { BUG_ON(ctx->state != SPU_STATE_SAVED); - if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags)) + if (test_and_clear_bit(SPU_SCHED_WAS_ACTIVE, &ctx->sched_flags) && + test_bit(SPU_SCHED_SPU_RUN, &ctx->sched_flags)) spu_activate(ctx, 0); spu_release(ctx); -- cgit v1.2.3