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Am 22.05.24 um 16:32 schrieb Thomas Hellström:<br>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<pre class="moz-quote-pre" wrap="">On Wed, 2024-05-22 at 07:52 +0200, Christian König wrote:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">Am 21.05.24 um 09:16 schrieb Thomas Hellström:
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">If contention and backoff occurs during a drm_exec ww transaction,
the contended lock is not locked again until the next orinary
attempt to lock a dma_resv lock. However, with the introduction of
drm_exec_trylock(), that doesn't work, since the locking of the
contended lock needs to be a sleeping lock. Neither can we ignore
locking the contended lock during a trylock since that would
violate
at least the ww_mutex annotations.
So resolve this by actually locking the contended lock during
drm_exec_retry_on_contention(). However, this introduces a new
point
of failure since locking the contended lock may return -EINTR.
Hence drm_exec_retry_on_contention() must take an error parameter
and
also return a value indicating success.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
After thinking more about that I have to pretty clearly NAK this.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">I thought we were beyond upfront NAKing in the first reply :/</pre>
</blockquote>
<br>
Well my memory could fail me, but I mentioned concerns on this
approach before.<br>
<br>
I was a bit annoyed seeing that again. But could as well be that my
response never got out or that I'm mixing things up.<br>
<br>
<span style="white-space: pre-wrap">
</span>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">It's an intentional design decision to guarantee that at the start of
the loop no object is locked.
This is because Sima and I wanted to integrate userptr handling into
drm_exec as well in the long term.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
First I agree the interface looks worse with this patch.
But I thought generic userptr handling were going to end up as a gpuvm
helper (without using GEM objects) as we've discussed previously.</pre>
</blockquote>
<br>
We might be talking past each other. That sounds like SVM, e.g. on
demand paging.<br>
<br>
What I mean is pre-faulting during command submission like radeon,
amdgpu and i915 do for the userptr handling.<br>
<br>
For that you need to re-start the whole handling similar to how you
need to re-start for the mutex locking when you detect that the page
array is stale, the difference is that you are not allowed to hold
any resv locks while pre-faulting.<br>
<br>
That's why it is a requirement that the drm_exec loop starts without
any locks held.<br>
<br>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<pre class="moz-quote-pre" wrap="">Anyway if still there would be helpers in drm_exec for some other
generic userptr solution, those need to be done before the
ww_acquire_ctx_init(). The contended locking here is done after, so I
can't really see how these would clash.</pre>
</blockquote>
<br>
Yes, that indeed was a problem. The ww_acquire_ctx_init() was
intentionally moved into drm_exec_cleanup() to partially prevent
that issue.<br>
<br>
I haven't fully figured out how to do handle everything exactly, but
at least in principle it can be made work. With this change here it
becomes impossible.<br>
<br>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<pre class="moz-quote-pre" wrap="">Still, If we need to come up with another solution, I think it's fair
we clearly sort out why.
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">I think we should just document that drm_exec_trylock() can't be used
to
lock the first BO in the loop and explicitly WARN if that's the case.
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
Unfortunately that's not sufficient for the general use-case. If we
want to keep the ttm_bo_vm approach of dropping the mmap lock when
there is contention on the bo resv, we need to be able to trylock on
first lock.</pre>
</blockquote>
<br>
Mhm, why exactly do we still have that dance in the first place?<br>
<br>
I mean we have sorted out the mmap() and dma_resv() locking order
long ago. See dma_resv_lockdep() which is enforcing that.<br>
<br>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<pre class="moz-quote-pre" wrap=""> Also bo creation is using trylock but might be able to use
a sleeping lock there. But if that sleeping lock triggers an -EDEADLK
(DEBUG_WW_MUTEX_SLOWPATH) we have the weird situation of referencing an
object that never was fully created as a contending object.</pre>
</blockquote>
<br>
I wanted to eliminate that as well by not validating the BO during
initialization any more.<br>
<br>
So bo creation would then be:<br>
<br>
ttm_bo_init(bo)<br>
<br>
drm_exec_while_not_all_locked() {<br>
drm_exec_prepare_object(bo, 1);<br>
<br>
ttm_bo_validate(bo);<br>
}<br>
<br>
if (r)<br>
ttm_bo_put(bo);<br>
<br>
return r;<br>
<br>
I have that on a branch here somewhere prepared, but never got the
time to clean it up.<br>
<br>
Regards,<br>
Christian.<br>
<br>
<blockquote type="cite" cite="mid:3f3d7fb84a11e8341a79331a0a682df0f3e8897d.camel@linux.intel.com">
<pre class="moz-quote-pre" wrap="">
So the only really working alternative solution I can see is that
drm_exec_trylock simply fails if there is a contended lock and we'd
need to live with the weird bo creation situation described above.
/Thomas
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
Regards,
Christian.
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">
Cc: Christian König <a class="moz-txt-link-rfc2396E" href="mailto:christian.koenig@amd.com"><christian.koenig@amd.com></a>
Cc: Somalapuram Amaranath <a class="moz-txt-link-rfc2396E" href="mailto:Amaranath.Somalapuram@amd.com"><Amaranath.Somalapuram@amd.com></a>
Cc: Matthew Brost <a class="moz-txt-link-rfc2396E" href="mailto:matthew.brost@intel.com"><matthew.brost@intel.com></a>
Cc: <a class="moz-txt-link-rfc2396E" href="mailto:dri-devel@lists.freedesktop.org"><dri-devel@lists.freedesktop.org></a>
Signed-off-by: Thomas Hellström <a class="moz-txt-link-rfc2396E" href="mailto:thomas.hellstrom@linux.intel.com"><thomas.hellstrom@linux.intel.com></a>
---
.../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 16 ++++-----
drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 6 ++--
drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c | 4 +--
drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c | 8 ++---
drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c | 8 ++---
drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c | 4 +--
drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c | 8 ++---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 2 +-
drivers/gpu/drm/drm_exec.c | 35
++++++++++++++-----
drivers/gpu/drm/drm_gpuvm.c | 8 ++---
drivers/gpu/drm/imagination/pvr_job.c | 2 +-
drivers/gpu/drm/msm/msm_gem_submit.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_uvmm.c | 2 +-
drivers/gpu/drm/tests/drm_exec_test.c | 12 +++----
drivers/gpu/drm/xe/xe_gt_pagefault.c | 4 +--
drivers/gpu/drm/xe/xe_vm.c | 10 +++---
include/drm/drm_exec.h | 23 +++++++++---
17 files changed, 92 insertions(+), 62 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index e4d4e55c08ad..4a08a692aa1f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -1152,12 +1152,12 @@ static int reserve_bo_and_vm(struct kgd_mem
*mem,
drm_exec_init(&ctx->exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
drm_exec_until_all_locked(&ctx->exec) {
ret = amdgpu_vm_lock_pd(vm, &ctx->exec, 2);
- drm_exec_retry_on_contention(&ctx->exec);
+ ret = drm_exec_retry_on_contention(&ctx->exec,
ret);
if (unlikely(ret))
goto error;
ret = drm_exec_prepare_obj(&ctx->exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base, 1);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&ctx->exec);
+ ret = drm_exec_retry_on_contention(&ctx->exec,
ret);
if (unlikely(ret))
goto error;
}
@@ -1199,14 +1199,14 @@ static int reserve_bo_and_cond_vms(struct
kgd_mem *mem,
ret = amdgpu_vm_lock_pd(entry->bo_va-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">base.vm,
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> &ctx->exec, 2);
- drm_exec_retry_on_contention(&ctx->exec);
+ ret = drm_exec_retry_on_contention(&ctx-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">exec, ret);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> if (unlikely(ret))
goto error;
++ctx->n_vms;
}
ret = drm_exec_prepare_obj(&ctx->exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base, 1);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&ctx->exec);
+ ret = drm_exec_retry_on_contention(&ctx->exec,
ret);
if (unlikely(ret))
goto error;
}
@@ -2619,7 +2619,7 @@ static int validate_invalid_user_pages(struct
amdkfd_process_info *process_info)
list_for_each_entry(peer_vm, &process_info-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">vm_list_head,
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> vm_list_node) {
ret = amdgpu_vm_lock_pd(peer_vm, &exec,
2);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec,
ret);
if (unlikely(ret))
goto unreserve_out;
}
@@ -2631,7 +2631,7 @@ static int validate_invalid_user_pages(struct
amdkfd_process_info *process_info)
gobj = &mem->bo->tbo.base;
ret = drm_exec_prepare_obj(&exec, gobj,
1);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec,
ret);
if (unlikely(ret))
goto unreserve_out;
}
@@ -2875,7 +2875,7 @@ int
amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct
dma_fence __rcu *
list_for_each_entry(peer_vm, &process_info-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">vm_list_head,
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> vm_list_node) {
ret = amdgpu_vm_lock_pd(peer_vm, &exec,
2);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec,
ret);
if (unlikely(ret)) {
pr_err("Locking VM PD failed, ret:
%d\n", ret);
goto ttm_reserve_fail;
@@ -2891,7 +2891,7 @@ int
amdgpu_amdkfd_gpuvm_restore_process_bos(void *info, struct
dma_fence __rcu *
gobj = &mem->bo->tbo.base;
ret = drm_exec_prepare_obj(&exec, gobj,
1);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec,
ret);
if (unlikely(ret)) {
pr_err("drm_exec_prepare_obj
failed, ret: %d\n", ret);
goto ttm_reserve_fail;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index ec888fc6ead8..299e46a6d934 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -897,7 +897,7 @@ static int amdgpu_cs_parser_bos(struct
amdgpu_cs_parser *p,
drm_exec_until_all_locked(&p->exec) {
r = amdgpu_vm_lock_pd(&fpriv->vm, &p->exec, 1 + p-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">gang_size);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&p->exec);
+ r = drm_exec_retry_on_contention(&p->exec, r);
if (unlikely(r))
goto out_free_user_pages;
@@ -905,7 +905,7 @@ static int amdgpu_cs_parser_bos(struct
amdgpu_cs_parser *p,
/* One fence for TTM and one for each CS
job */
r = drm_exec_prepare_obj(&p->exec, &e->bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base,
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> 1 + p-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">gang_size);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&p->exec);
+ r = drm_exec_retry_on_contention(&p->exec,
r);
if (unlikely(r))
goto out_free_user_pages;
@@ -915,7 +915,7 @@ static int amdgpu_cs_parser_bos(struct
amdgpu_cs_parser *p,
if (p->uf_bo) {
r = drm_exec_prepare_obj(&p->exec, &p-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">uf_bo->tbo.base,
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> 1 + p-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">gang_size);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&p->exec);
+ r = drm_exec_retry_on_contention(&p->exec,
r);
if (unlikely(r))
goto out_free_user_pages;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
index cfdf558b48b6..8b2b86c7a6c5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_csa.c
@@ -74,7 +74,7 @@ int amdgpu_map_static_csa(struct amdgpu_device
*adev, struct amdgpu_vm *vm,
r = amdgpu_vm_lock_pd(vm, &exec, 0);
if (likely(!r))
r = drm_exec_lock_obj(&exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r)) {
DRM_ERROR("failed to reserve CSA,PD BOs:
err=%d\n", r);
goto error;
@@ -114,7 +114,7 @@ int amdgpu_unmap_static_csa(struct
amdgpu_device *adev, struct amdgpu_vm *vm,
r = amdgpu_vm_lock_pd(vm, &exec, 0);
if (likely(!r))
r = drm_exec_lock_obj(&exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r)) {
DRM_ERROR("failed to reserve CSA,PD BOs:
err=%d\n", r);
goto error;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 67c234bcf89f..17e16c971e21 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -239,12 +239,12 @@ static void amdgpu_gem_object_close(struct
drm_gem_object *obj,
drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
drm_exec_until_all_locked(&exec) {
r = drm_exec_prepare_obj(&exec, &bo->tbo.base, 1);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
r = amdgpu_vm_lock_pd(vm, &exec, 0);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
}
@@ -776,13 +776,13 @@ int amdgpu_gem_va_ioctl(struct drm_device
*dev, void *data,
drm_exec_until_all_locked(&exec) {
if (gobj) {
r = drm_exec_lock_obj(&exec, gobj);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec,
r);
if (unlikely(r))
goto error;
}
r = amdgpu_vm_lock_pd(&fpriv->vm, &exec, 2);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
index 5ca5c47ab54e..1b1a5147606e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mes.c
@@ -1221,12 +1221,12 @@ int amdgpu_mes_ctx_map_meta_data(struct
amdgpu_device *adev,
drm_exec_until_all_locked(&exec) {
r = drm_exec_lock_obj(&exec,
&ctx_data->meta_data_obj-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error_fini_exec;
r = amdgpu_vm_lock_pd(vm, &exec, 0);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error_fini_exec;
}
@@ -1292,12 +1292,12 @@ int amdgpu_mes_ctx_unmap_meta_data(struct
amdgpu_device *adev,
drm_exec_until_all_locked(&exec) {
r = drm_exec_lock_obj(&exec,
&ctx_data->meta_data_obj-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
r = amdgpu_vm_lock_pd(vm, &exec, 0);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
index e22cb2b5cd92..72b8213e352c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_seq64.c
@@ -77,7 +77,7 @@ int amdgpu_seq64_map(struct amdgpu_device *adev,
struct amdgpu_vm *vm,
r = amdgpu_vm_lock_pd(vm, &exec, 0);
if (likely(!r))
r = drm_exec_lock_obj(&exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error;
}
@@ -138,7 +138,7 @@ void amdgpu_seq64_unmap(struct amdgpu_device
*adev, struct amdgpu_fpriv *fpriv)
r = amdgpu_vm_lock_pd(vm, &exec, 0);
if (likely(!r))
r = drm_exec_lock_obj(&exec, &bo-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">tbo.base);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error;
}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
index e01c1c8e64c4..63392ce43945 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_umsch_mm.c
@@ -89,12 +89,12 @@ static int map_ring_data(struct amdgpu_device
*adev, struct amdgpu_vm *vm,
drm_exec_init(&exec, 0, 0);
drm_exec_until_all_locked(&exec) {
r = drm_exec_lock_obj(&exec, &bo->tbo.base);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error_fini_exec;
r = amdgpu_vm_lock_pd(vm, &exec, 0);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto error_fini_exec;
}
@@ -152,12 +152,12 @@ static int unmap_ring_data(struct
amdgpu_device *adev, struct amdgpu_vm *vm,
drm_exec_init(&exec, 0, 0);
drm_exec_until_all_locked(&exec) {
r = drm_exec_lock_obj(&exec, &bo->tbo.base);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
r = amdgpu_vm_lock_pd(vm, &exec, 0);
- drm_exec_retry_on_contention(&exec);
+ r = drm_exec_retry_on_contention(&exec, r);
if (unlikely(r))
goto out_unlock;
}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 386875e6eb96..a3aa7fd22f6a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1499,7 +1499,7 @@ static int svm_range_reserve_bos(struct
svm_validate_context *ctx, bool intr)
vm = drm_priv_to_vm(pdd->drm_priv);
r = amdgpu_vm_lock_pd(vm, &ctx->exec, 2);
- drm_exec_retry_on_contention(&ctx->exec);
+ r = drm_exec_retry_on_contention(&ctx-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">exec, r);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> if (unlikely(r)) {
pr_debug("failed %d to reserve
bo\n", r);
goto unreserve_out;
diff --git a/drivers/gpu/drm/drm_exec.c
b/drivers/gpu/drm/drm_exec.c
index 2da094bdf8a4..3770a5d30213 100644
--- a/drivers/gpu/drm/drm_exec.c
+++ b/drivers/gpu/drm/drm_exec.c
@@ -28,12 +28,12 @@
* drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT);
* drm_exec_until_all_locked(&exec) {
* ret = drm_exec_prepare_obj(&exec, boA, 1);
- * drm_exec_retry_on_contention(&exec);
+ * ret = drm_exec_retry_on_contention(&exec, ret);
* if (ret)
* goto error;
*
* ret = drm_exec_prepare_obj(&exec, boB, 1);
- * drm_exec_retry_on_contention(&exec);
+ * ret = drm_exec_retry_on_contention(&exec, ret);
* if (ret)
* goto error;
* }
@@ -48,7 +48,8 @@
*/
/* Dummy value used to initially enter the retry loop */
-#define DRM_EXEC_DUMMY ((void *)~0)
+#define DRM_EXEC_DUMMY ERR_PTR(-ESTALE)
+#define DRM_EXEC_CONTENDED ERR_PTR(-EDEADLK)
/* Unlock all objects and drop references */
static void drm_exec_unlock_all(struct drm_exec *exec)
@@ -131,8 +132,7 @@ bool drm_exec_cleanup(struct drm_exec *exec)
return true;
}
- drm_exec_unlock_all(exec);
- exec->num_objects = 0;
+ exec->contended = NULL;
return true;
}
EXPORT_SYMBOL(drm_exec_cleanup);
@@ -194,6 +194,27 @@ static int drm_exec_lock_contended(struct
drm_exec *exec)
return ret;
}
+/**
+ * drm_exec_handle_contended() - Perform cleanup before a ww
transaction restart
+ * @exec: Pointer to the drm_exec object.
+ *
+ * Unlocks all held resvs and re-locks the contended object.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int drm_exec_handle_contended(struct drm_exec *exec)
+{
+ int ret;
+
+ drm_exec_unlock_all(exec);
+ exec->num_objects = 0;
+ ret = drm_exec_lock_contended(exec);
+ exec->contended = DRM_EXEC_CONTENDED;
+
+ return ret;
+}
+EXPORT_SYMBOL(drm_exec_handle_contended);
+
/**
* drm_exec_lock_obj - lock a GEM object for use
* @exec: the drm_exec object with the state
@@ -209,10 +230,6 @@ int drm_exec_lock_obj(struct drm_exec *exec,
struct drm_gem_object *obj)
{
int ret;
- ret = drm_exec_lock_contended(exec);
- if (unlikely(ret))
- return ret;
-
if (exec->prelocked == obj) {
drm_gem_object_put(exec->prelocked);
exec->prelocked = NULL;
diff --git a/drivers/gpu/drm/drm_gpuvm.c
b/drivers/gpu/drm/drm_gpuvm.c
index f9eb56f24bef..0923d6ae18e2 100644
--- a/drivers/gpu/drm/drm_gpuvm.c
+++ b/drivers/gpu/drm/drm_gpuvm.c
@@ -1254,18 +1254,18 @@ drm_gpuvm_exec_lock(struct drm_gpuvm_exec
*vm_exec)
drm_exec_until_all_locked(exec) {
ret = drm_gpuvm_prepare_vm(gpuvm, exec,
num_fences);
- drm_exec_retry_on_contention(exec);
+ ret = drm_exec_retry_on_contention(exec, ret);
if (ret)
goto err;
ret = drm_gpuvm_prepare_objects(gpuvm, exec,
num_fences);
- drm_exec_retry_on_contention(exec);
+ ret = drm_exec_retry_on_contention(exec, ret);
if (ret)
goto err;
if (vm_exec->extra.fn) {
ret = vm_exec->extra.fn(vm_exec);
- drm_exec_retry_on_contention(exec);
+ ret = drm_exec_retry_on_contention(exec,
ret);
if (ret)
goto err;
}
@@ -1346,7 +1346,7 @@ drm_gpuvm_exec_lock_range(struct
drm_gpuvm_exec *vm_exec,
drm_exec_until_all_locked(exec) {
ret = drm_gpuvm_prepare_range(gpuvm, exec, addr,
range,
vm_exec-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">num_fences);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(exec);
+ ret = drm_exec_retry_on_contention(exec, ret);
if (ret)
goto err;
}
diff --git a/drivers/gpu/drm/imagination/pvr_job.c
b/drivers/gpu/drm/imagination/pvr_job.c
index 78c2f3c6dce0..6e0ce6c4576c 100644
--- a/drivers/gpu/drm/imagination/pvr_job.c
+++ b/drivers/gpu/drm/imagination/pvr_job.c
@@ -574,7 +574,7 @@ prepare_job_resvs_for_each(struct drm_exec
*exec, struct pvr_job_data *job_data,
drm_exec_until_all_locked(exec) {
int err = jobs_lock_all_objs(exec, job_data,
job_count);
- drm_exec_retry_on_contention(exec);
+ err = drm_exec_retry_on_contention(exec, err);
if (err)
return err;
}
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c
b/drivers/gpu/drm/msm/msm_gem_submit.c
index fba78193127d..01992b43ea4b 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -259,7 +259,7 @@ static int submit_lock_objects(struct
msm_gem_submit *submit)
for (unsigned i = 0; i < submit->nr_bos; i++) {
struct drm_gem_object *obj = submit-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">bos[i].obj;
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap=""> ret = drm_exec_prepare_obj(&submit->exec,
obj, 1);
- drm_exec_retry_on_contention(&submit-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">exec);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">+ ret =
drm_exec_retry_on_contention(&submit->exec, ret);
if (ret)
goto error;
}
diff --git a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
index ee02cd833c5e..0c871634fdfb 100644
--- a/drivers/gpu/drm/nouveau/nouveau_uvmm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_uvmm.c
@@ -1350,7 +1350,7 @@ nouveau_uvmm_bind_job_submit(struct
nouveau_job *job,
drm_exec_init(exec, vme->flags, 0);
drm_exec_until_all_locked(exec) {
ret = bind_lock_validate(job, exec, vme-
</pre>
<blockquote type="cite">
<pre class="moz-quote-pre" wrap="">num_fences);
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">- drm_exec_retry_on_contention(exec);
+ ret = drm_exec_retry_on_contention(exec, ret);
if (ret) {
op = list_last_op(&bind_job->ops);
goto unwind;
diff --git a/drivers/gpu/drm/tests/drm_exec_test.c
b/drivers/gpu/drm/tests/drm_exec_test.c
index 81f928a429ba..28558fdb08df 100644
--- a/drivers/gpu/drm/tests/drm_exec_test.c
+++ b/drivers/gpu/drm/tests/drm_exec_test.c
@@ -63,7 +63,7 @@ static void test_lock(struct kunit *test)
drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
drm_exec_until_all_locked(&exec) {
ret = drm_exec_lock_obj(&exec, &gobj);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
@@ -83,14 +83,14 @@ static void test_lock_unlock(struct kunit
*test)
drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
drm_exec_until_all_locked(&exec) {
ret = drm_exec_lock_obj(&exec, &gobj);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
drm_exec_unlock_obj(&exec, &gobj);
ret = drm_exec_lock_obj(&exec, &gobj);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
@@ -110,13 +110,13 @@ static void test_duplicates(struct kunit
*test)
drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
drm_exec_until_all_locked(&exec) {
ret = drm_exec_lock_obj(&exec, &gobj);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
ret = drm_exec_lock_obj(&exec, &gobj);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
@@ -137,7 +137,7 @@ static void test_prepare(struct kunit *test)
drm_exec_init(&exec, DRM_EXEC_INTERRUPTIBLE_WAIT, 0);
drm_exec_until_all_locked(&exec) {
ret = drm_exec_prepare_obj(&exec, &gobj, 1);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
KUNIT_EXPECT_EQ(test, ret, 0);
if (ret)
break;
diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c
b/drivers/gpu/drm/xe/xe_gt_pagefault.c
index 040dd142c49c..20ec1ab1b52d 100644
--- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
+++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
@@ -200,7 +200,7 @@ static int handle_pagefault(struct xe_gt *gt,
struct pagefault *pf)
drm_exec_init(&exec, 0, 0);
drm_exec_until_all_locked(&exec) {
ret = xe_pf_begin(&exec, vma, atomic, tile->id);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
if (ret)
goto unlock_dma_resv;
@@ -543,7 +543,7 @@ static int handle_acc(struct xe_gt *gt, struct
acc *acc)
drm_exec_init(&exec, 0, 0);
drm_exec_until_all_locked(&exec) {
ret = xe_pf_begin(&exec, vma, true, tile->id);
- drm_exec_retry_on_contention(&exec);
+ ret = drm_exec_retry_on_contention(&exec, ret);
if (ret)
break;
}
diff --git a/drivers/gpu/drm/xe/xe_vm.c
b/drivers/gpu/drm/xe/xe_vm.c
index e2ec148c9c33..335524e803e7 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -501,7 +501,7 @@ static void preempt_rebind_work_func(struct
work_struct *w)
bool done = false;
err = xe_preempt_work_begin(&exec, vm, &done);
- drm_exec_retry_on_contention(&exec);
+ err = drm_exec_retry_on_contention(&exec, err);
if (err || done) {
drm_exec_fini(&exec);
if (err &&
xe_vm_validate_should_retry(&exec, err, &end))
@@ -1052,7 +1052,7 @@ static void xe_vma_destroy_unlocked(struct
xe_vma *vma)
drm_exec_init(&exec, 0, 0);
drm_exec_until_all_locked(&exec) {
err = xe_vm_lock_vma(&exec, vma);
- drm_exec_retry_on_contention(&exec);
+ err = drm_exec_retry_on_contention(&exec, err);
if (XE_WARN_ON(err))
break;
}
@@ -2148,11 +2148,11 @@ static struct xe_vma *new_vma(struct xe_vm
*vm, struct drm_gpuva_op_map *op,
err = 0;
if (!bo->vm) {
err = drm_exec_lock_obj(&exec,
xe_vm_obj(vm));
-
drm_exec_retry_on_contention(&exec);
+ err =
drm_exec_retry_on_contention(&exec, err);
}
if (!err) {
err = drm_exec_lock_obj(&exec,
&bo->ttm.base);
-
drm_exec_retry_on_contention(&exec);
+ err =
drm_exec_retry_on_contention(&exec, err);
}
if (err) {
drm_exec_fini(&exec);
@@ -2884,7 +2884,7 @@ static int vm_bind_ioctl_ops_execute(struct
xe_vm *vm,
DRM_EXEC_IGNORE_DUPLICATES, 0);
drm_exec_until_all_locked(&exec) {
err = vm_bind_ioctl_ops_lock_and_prep(&exec, vm,
vops);
- drm_exec_retry_on_contention(&exec);
+ err = drm_exec_retry_on_contention(&exec, err);
if (err)
goto unlock;
diff --git a/include/drm/drm_exec.h b/include/drm/drm_exec.h
index aa786b828a0a..fafb40d96e38 100644
--- a/include/drm/drm_exec.h
+++ b/include/drm/drm_exec.h
@@ -51,6 +51,8 @@ struct drm_exec {
struct drm_gem_object *prelocked;
};
+int drm_exec_handle_contended(struct drm_exec *exec);
+
/**
* drm_exec_obj() - Return the object for a give drm_exec index
* @exec: Pointer to the drm_exec context
@@ -113,15 +115,26 @@ __PASTE(__drm_exec_,
__LINE__): \
/**
* drm_exec_retry_on_contention - restart the loop to grap all
locks
* @exec: drm_exec object
+ * @_ret: The current error status
*
* Control flow helper to continue when a contention was detected
and we need to
* clean up and re-start the loop to prepare all GEM objects.
+ *
+ * Return: If no loop restart occurred: The error status.
*/
-#define drm_exec_retry_on_contention(exec) \
- do { \
- if (unlikely(drm_exec_is_contended(exec))) \
- goto *__drm_exec_retry_ptr; \
- } while (0)
+#define drm_exec_retry_on_contention(exec,
_ret) \
+ ({
\
+ struct drm_exec *__exec =
(exec); \
+ int __ret =
(_ret); \
+
\
+ if (unlikely(drm_exec_is_contended(__exec)))
{ \
+ WARN_ON(__ret != -
EDEADLK); \
+ __ret =
drm_exec_handle_contended(__exec); \
+ if
(!__ret) \
+ goto
*__drm_exec_retry_ptr; \
+ }
\
+ __ret;
\
+ })
/**
* drm_exec_is_contended - check for contention
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
</pre>
</blockquote>
<pre class="moz-quote-pre" wrap="">
</pre>
</blockquote>
<br>
</body>
</html>