At the very least I don't get the hangs like I used to before the
patchset so this patch isn't regressing any of that behaviour.
Tom
On 13/10/17 07:06 AM, Liu, Monk wrote:
Yeah, this one looks good
You can put my reviewed-by on it
*From:*Koenig, Christian
*Sent:* 2017年10月13日18:14
*To:* Liu, Monk <monk....@amd.com>; Nicolai Hähnle <nhaeh...@gmail.com>;
amd-gfx@lists.freedesktop.org
*Subject:* Re: regression with d6c650c0a8f6f671e49553725e1db541376d95f2
Good point as well. How about the attached version?
This time we keep an extra reference in amd_sched_process_job() until we
are sure that we don't need the s_fence any more.
Regards,
Christian.
Am 13.10.2017 um 11:13 schrieb Liu, Monk:
your patch looks good, do you think we should also do this:
void amd_sched_fence_scheduled(struct amd_sched_fence *fence)
{
- int ret = fence_signal(&fence->scheduled);
+ int ret;
+
+ fence_get(&fence->scheduled;)
+ ret = fence_signal(&fence->scheduled);
if (!ret)
FENCE_TRACE(&fence->scheduled, "signaled from irq
context\n");
else
FENCE_TRACE(&fence->scheduled, "was already
signaled\n");
+ fence_put(&fence->scheduled);
}
------------------------------------------------------------------------
*From:*Koenig, Christian
*Sent:* Friday, October 13, 2017 5:00:27 PM
*To:* Liu, Monk; Nicolai Hähnle; amd-gfx@lists.freedesktop.org
<mailto:amd-gfx@lists.freedesktop.org>
*Subject:* Re: regression with d6c650c0a8f6f671e49553725e1db541376d95f2
There is chance that free_job() called before that
“trace_amd_sched_process_job”, correct?
Correct, but that is harmless.
Take a look what trace_amd_sched_process_job actually does, it just
prints the pointer of the fence structure (but the pointer might be
stale at this point).
Nevertheless you are right that this is really ugly.
How about the attached patch to fix the issue?
Regards,
Christian.
Am 13.10.2017 um 10:51 schrieb Liu, Monk:
The free_job() is called in sched_job_finish() which is queued
on a WORK and scheduled from that “amd_sched_fence_finished()”
So the finishing timing of free_job() is asynchronized with
sched_process_job()
There is chance that free_job() called before that
“trace_amd_sched_process_job”, correct?
And if so the s_fence referred by it maybe a wild pointer
BR Monk
*From:*Liu, Monk
*Sent:* 2017年10月13日16:49
*To:* Koenig, Christian <christian.koe...@amd.com>
<mailto:christian.koe...@amd.com>; Nicolai Hähnle
<nhaeh...@gmail.com> <mailto:nhaeh...@gmail.com>;
amd-gfx@lists.freedesktop.org <mailto:amd-gfx@lists.freedesktop.org>
*Subject:* RE: regression with
d6c650c0a8f6f671e49553725e1db541376d95f2
No that’s not true
The free_job() is called in sched_job_finish() which is queued
on a WORK and scheduled from that “amd_sched_fence_finished()”
So the finishing timing of free_job() is asynchronized with
sched_process_job()
How can you sure free_job() must before
“trace_amd_sched_process_job” ?
*From:*Koenig, Christian
*Sent:* 2017年10月13日16:43
*To:* Liu, Monk <monk....@amd.com <mailto:monk....@amd.com>>;
Nicolai Hähnle <nhaeh...@gmail.com <mailto:nhaeh...@gmail.com>>;
amd-gfx@lists.freedesktop.org <mailto:amd-gfx@lists.freedesktop.org>
*Subject:* Re: regression with
d6c650c0a8f6f671e49553725e1db541376d95f2
The free_job() callback is called only way after the job has
finished.
That is one change actually made by you to the code :)
Christian.
Am 13.10.2017 um 10:39 schrieb Liu, Monk:
I doubt it would always work fine…
First, we have FENCE_TRACE reference s_fence->finished after
“fence_signal(&fence->finished)”
Second, we have trace_amd_sched_proess_job(s_fence) after
“amd_sched_fence_finished()”,
If you put the finished before free_job() and by coincidence
the job_finish() get very soon executed you’ll have odds to
hit wild pointer on above two cases
BR Monk
*From:*Koenig, Christian
*Sent:* 2017年10月13日16:17
*To:* Liu, Monk <monk....@amd.com>
<mailto:monk....@amd.com>; Nicolai Hähnle
<nhaeh...@gmail.com> <mailto:nhaeh...@gmail.com>;
amd-gfx@lists.freedesktop.org
<mailto:amd-gfx@lists.freedesktop.org>
*Subject:* Re: regression with
d6c650c0a8f6f671e49553725e1db541376d95f2
Yeah, that change is actually incorrect and should be reverted.
What we really need to do is remove dropping
sched_job->s_fence from amd_sched_process_job() into
amd_sched_job_finish() directly before the call to free_job().
Regards,
Christian.
Am 13.10.2017 um 09:24 schrieb Liu, Monk:
commit d6c650c0a8f6f671e49553725e1db541376d95f2
Author: Nicolai Hähnle <nicolai.haeh...@amd.com>
<mailto:nicolai.haeh...@amd.com>
@@ -611,6 +611,10 @@ static int amd_sched_main(void *param)
fence = sched->ops->run_job(sched_job);
amd_sched_fence_scheduled(s_fence);
+
+ /* amd_sched_process_job drops the job's
reference of the fence. */
+ sched_job->s_fence = NULL;
+
if (fence) {
s_fence->parent =
dma_fence_get(fence);
r =
dma_fence_add_callback(fence, &s_fence->cb,
Hi Nicolai
with this patch, you will break
"amdgpu_sched_hw_job_reset()"routine:
void
amd_sched_hw_job_reset(struct amd_gpu_scheduler
*sched)
{
struct amd_sched_job
*s_job;
spin_lock(&sched->job_list_lock);
list_for_each_entry_reverse(s_job,
&sched->ring_mirror_list, node) {
if (s_job->s_fence->parent
&&
fence_remove_callback(s_job->s_fence->parent,
&s_job->s_fence->cb))
{
fence_put(s_job->s_fence->parent);
s_job->s_fence->parent
=
NULL;
atomic_dec(&sched->hw_rq_count);
}
}
spin_unlock(&sched->job_list_lock);
}
see that without sched_job->s_fence, you cannot remove
the callback from its hw fence,
any idea??
BR Monk
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