[PATCH 1/5] drm/amdgpu:keep ctx alive till all job finished
Christian König
deathsimple at vodafone.de
Wed May 3 09:11:45 UTC 2017
> > 1) fence_context have chance to incorrectly represent the context
> behind it, because the number can be used up and will wrapped around
> from beginning
> No, fence_context is unique in global in kernel.
Yeah, I would go with that as well.
You note the fence_context of the job which caused the trouble.
Then take a look at all jobs on the recovery list and remove the ones
with the same fence_context number.
Then take a look at all entities on the runlist and remove the one with
the same fence_context number. If it is already freed you won't find
any, but that shouldn't be a problem.
This way you effectively can prevent other jobs from the same context
from running and the context query can simply check if the entity is
still on the runlist to figure out if it was guilty or not.
Regards,
Christian.
Am 03.05.2017 um 09:23 schrieb zhoucm1:
>
>
> On 2017年05月03日 14:02, Liu, Monk wrote:
>> You can add ctx as filed of job, but not get reference of it, when
>> you try to use ctx, just check if ctx == NULL.
>> > that doesn't work at all... job->ctx will always be non-NULL after
>> it is initialized, you just refer to a wild pointer after CTX released
> job->ctx is a **ctx, which could resolve your this concern.
>
>>
>> Another stupid method:
>> Use idr_for_each_entry(..job->vm->ctx_mgr...) and compare the
>> job->fence->fence_context with ctx->ring[].entity->fence_context. if
>> not found, then ctx is freed, otherwise you can do your things for
>> this ctx.
>> > 1) fence_context have chance to incorrectly represent the context
>> behind it, because the number can be used up and will wrapped around
>> from beginning
> No, fence_context is unique in global in kernel.
>
> Regards,
> David Zhou
>> 2) why not just keep CTX alive, which is much simple than this method
>>
>> BR
>>
>> -----Original Message-----
>> From: Zhou, David(ChunMing)
>> Sent: Wednesday, May 03, 2017 12:54 PM
>> To: Liu, Monk <Monk.Liu at amd.com>; Liu, Monk <Monk.Liu at amd.com>;
>> Christian König <deathsimple at vodafone.de>; amd-gfx at lists.freedesktop.org
>> Subject: RE: [PATCH 1/5] drm/amdgpu:keep ctx alive till all job finished
>>
>> You can add ctx as filed of job, but not get reference of it, when
>> you try to use ctx, just check if ctx == NULL.
>>
>> Another stupid method:
>> Use idr_for_each_entry(..job->vm->ctx_mgr...) and compare the
>> job->fence->fence_context with ctx->ring[].entity->fence_context. if
>> not found, then ctx is freed, otherwise you can do your things for
>> this ctx.
>>
>> Regards,
>> David Zhou
>>
>> -----Original Message-----
>> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On
>> Behalf Of Liu, Monk
>> Sent: Wednesday, May 03, 2017 11:57 AM
>> To: Liu, Monk <Monk.Liu at amd.com>; Christian König
>> <deathsimple at vodafone.de>; amd-gfx at lists.freedesktop.org
>> Subject: RE: [PATCH 1/5] drm/amdgpu:keep ctx alive till all job finished
>>
>> @Christian,
>>
>> The thing is I need mark all entities behind this timeout job as
>> guilty, so I use a member in entity named "ptr_guilty", to point to
>> The member in amdgpu_ctx named "guilty", that way read
>> *entity->ptr_guilty can get you if this entity is "invalid", and set
>> *entity->ptr_guilty Can let you set all entities belongs to the
>> context as "invalid".
>>
>> Above logic is to guarantee we can kick out all guilty entities in
>> entity kfifo, and also block all IOCTL with a ctx handle point to
>> this guilty context, And we only recovery other jobs/entities/context
>> after scheduler unparked
>>
>> If you reject the patch to keep ctx alive till all jobs signaled,
>> please give me a solution to satisfy above logic
>>
>> BR Monk
>>
>> -----Original Message-----
>> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On
>> Behalf Of Liu, Monk
>> Sent: Wednesday, May 03, 2017 11:31 AM
>> To: Christian König <deathsimple at vodafone.de>;
>> amd-gfx at lists.freedesktop.org
>> Subject: RE: [PATCH 1/5] drm/amdgpu:keep ctx alive till all job finished
>>
>> 1, This is necessary otherwise how can I access entity pointer after
>> a job timedout , and why it is dangerous ?
>> 2, what's the status field in the fences you were referring to ? I
>> need to judge if it could satisfy my requirement
>>
>>
>>
>> -----Original Message-----
>> From: Christian König [mailto:deathsimple at vodafone.de]
>> Sent: Monday, May 01, 2017 10:48 PM
>> To: Liu, Monk <Monk.Liu at amd.com>; amd-gfx at lists.freedesktop.org
>> Subject: Re: [PATCH 1/5] drm/amdgpu:keep ctx alive till all job finished
>>
>> Am 01.05.2017 um 09:22 schrieb Monk Liu:
>> > for TDR guilty context feature, we need access ctx/s_entity field
>> > member through sched job pointer,so ctx must keep alive till all job
>> > from it signaled.
>>
>> NAK, that is unnecessary and quite dangerous.
>>
>> Instead we have the designed status field in the fences which should
>> be checked for that.
>>
>> Regards,
>> Christian.
>>
>> >
>> > Change-Id: Ib87e9502f7a5c8c054c7e56956d7f7ad75998e43
>> > Signed-off-by: Monk Liu <Monk.Liu at amd.com>
>> > ---
>> > drivers/gpu/drm/amd/amdgpu/amdgpu.h | 6 +++++-
>> > drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 2 +-
>> > drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 9 +++++++++
>> > drivers/gpu/drm/amd/amdgpu/amdgpu_job.c | 9 +++++++--
>> > drivers/gpu/drm/amd/scheduler/gpu_scheduler.c | 6 ------
>> > drivers/gpu/drm/amd/scheduler/gpu_scheduler.h | 1 +
>> > 6 files changed, 23 insertions(+), 10 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> > b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> > index e330009..8e031d6 100644
>> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> > @@ -760,10 +760,12 @@ struct amdgpu_ib {
>> > uint32_t flags;
>> > };
>> >
>> > +struct amdgpu_ctx;
>> > +
>> > extern const struct amd_sched_backend_ops amdgpu_sched_ops;
>> >
>> > int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
>> > - struct amdgpu_job **job, struct amdgpu_vm *vm);
>> > + struct amdgpu_job **job, struct amdgpu_vm *vm,
>> struct
>> > +amdgpu_ctx *ctx);
>> > int amdgpu_job_alloc_with_ib(struct amdgpu_device *adev, unsigned
>> size,
>> > struct amdgpu_job **job);
>> >
>> > @@ -802,6 +804,7 @@ struct amdgpu_ctx_mgr {
>> >
>> > struct amdgpu_ctx *amdgpu_ctx_get(struct amdgpu_fpriv *fpriv,
>> uint32_t id);
>> > int amdgpu_ctx_put(struct amdgpu_ctx *ctx);
>> > +struct amdgpu_ctx *amdgpu_ctx_kref_get(struct amdgpu_ctx *ctx);
>> >
>> > uint64_t amdgpu_ctx_add_fence(struct amdgpu_ctx *ctx, struct
>> amdgpu_ring *ring,
>> > struct fence *fence);
>> > @@ -1129,6 +1132,7 @@ struct amdgpu_job {
>> > struct amdgpu_sync sync;
>> > struct amdgpu_ib *ibs;
>> > struct fence *fence; /* the hw fence */
>> > + struct amdgpu_ctx *ctx;
>> > uint32_t preamble_status;
>> > uint32_t num_ibs;
>> > void *owner;
>> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> > index 699f5fe..267fb65 100644
>> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> > @@ -234,7 +234,7 @@ int amdgpu_cs_parser_init(struct
>> amdgpu_cs_parser *p, void *data)
>> > }
>> > }
>> >
>> > - ret = amdgpu_job_alloc(p->adev, num_ibs, &p->job, vm);
>> > + ret = amdgpu_job_alloc(p->adev, num_ibs, &p->job, vm, p->ctx);
>> > if (ret)
>> > goto free_all_kdata;
>> >
>> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> > index b4bbbb3..81438af 100644
>> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
>> > @@ -25,6 +25,13 @@
>> > #include <drm/drmP.h>
>> > #include "amdgpu.h"
>> >
>> > +struct amdgpu_ctx *amdgpu_ctx_kref_get(struct amdgpu_ctx *ctx) {
>> > + if (ctx)
>> > + kref_get(&ctx->refcount);
>> > + return ctx;
>> > +}
>> > +
>> > static int amdgpu_ctx_init(struct amdgpu_device *adev, struct
>> amdgpu_ctx *ctx)
>> > {
>> > unsigned i, j;
>> > @@ -56,6 +63,8 @@ static int amdgpu_ctx_init(struct amdgpu_device
>> *adev, struct amdgpu_ctx *ctx)
>> > rq, amdgpu_sched_jobs);
>> > if (r)
>> > goto failed;
>> > +
>> > + ctx->rings[i].entity.ptr_guilty = &ctx->guilty; /*
>> kernel entity
>> > +doesn't have ptr_guilty */
>> > }
>> >
>> > return 0;
>> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> > index 690ef3d..208da11 100644
>> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
>> > @@ -40,7 +40,7 @@ static void amdgpu_job_timedout(struct
>> amd_sched_job *s_job)
>> > }
>> >
>> > int amdgpu_job_alloc(struct amdgpu_device *adev, unsigned num_ibs,
>> > - struct amdgpu_job **job, struct amdgpu_vm *vm)
>> > + struct amdgpu_job **job, struct amdgpu_vm *vm,
>> struct
>> > +amdgpu_ctx *ctx)
>> > {
>> > size_t size = sizeof(struct amdgpu_job);
>> >
>> > @@ -57,6 +57,7 @@ int amdgpu_job_alloc(struct amdgpu_device *adev,
>> unsigned num_ibs,
>> > (*job)->vm = vm;
>> > (*job)->ibs = (void *)&(*job)[1];
>> > (*job)->num_ibs = num_ibs;
>> > + (*job)->ctx = amdgpu_ctx_kref_get(ctx);
>> >
>> > amdgpu_sync_create(&(*job)->sync);
>> >
>> > @@ -68,7 +69,7 @@ int amdgpu_job_alloc_with_ib(struct amdgpu_device
>> *adev, unsigned size,
>> > {
>> > int r;
>> >
>> > - r = amdgpu_job_alloc(adev, 1, job, NULL);
>> > + r = amdgpu_job_alloc(adev, 1, job, NULL, NULL);
>> > if (r)
>> > return r;
>> >
>> > @@ -94,6 +95,10 @@ void amdgpu_job_free_resources(struct amdgpu_job
>> *job)
>> > static void amdgpu_job_free_cb(struct amd_sched_job *s_job)
>> > {
>> > struct amdgpu_job *job = container_of(s_job, struct amdgpu_job,
>> > base);
>> > + struct amdgpu_ctx *ctx = job->ctx;
>> > +
>> > + if (ctx)
>> > + amdgpu_ctx_put(ctx);
>> >
>> > fence_put(job->fence);
>> > amdgpu_sync_free(&job->sync);
>> > diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
>> > b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
>> > index 6f4e31f..9100ca8 100644
>> > --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
>> > +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
>> > @@ -208,12 +208,6 @@ void amd_sched_entity_fini(struct
>> amd_gpu_scheduler *sched,
>> > if (!amd_sched_entity_is_initialized(sched, entity))
>> > return;
>> >
>> > - /**
>> > - * The client will not queue more IBs during this fini,
>> consume existing
>> > - * queued IBs
>> > - */
>> > - wait_event(sched->job_scheduled,
>> amd_sched_entity_is_idle(entity));
>> > -
>> > amd_sched_rq_remove_entity(rq, entity);
>> > kfifo_free(&entity->job_queue);
>> > }
>> > diff --git a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> > b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> > index 8cb41d3..ccbbcb0 100644
>> > --- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> > +++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.h
>> > @@ -49,6 +49,7 @@ struct amd_sched_entity {
>> >
>> > struct fence *dependency;
>> > struct fence_cb cb;
>> > + bool *ptr_guilty;
>> > };
>> >
>> > /**
>>
>>
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