On 5/22/25 16:27, Tvrtko Ursulin wrote:
>
> On 22/05/2025 14:41, Christian König wrote:
>> Since we already iterated over the xarray we know at which index the new
>> entry should be stored. So instead of using xa_alloc use xa_store and
>> write into the index directly.
>>
>> Signed-off-by: Christian König <christian.koe...@amd.com>
>> ---
>> drivers/gpu/drm/scheduler/sched_main.c | 12 ++++++------
>> 1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>> b/drivers/gpu/drm/scheduler/sched_main.c
>> index f7118497e47a..d2d64bf17c96 100644
>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>> @@ -871,10 +871,8 @@ EXPORT_SYMBOL(drm_sched_job_arm);
>> int drm_sched_job_add_dependency(struct drm_sched_job *job,
>> struct dma_fence *fence)
>> {
>> + unsigned long index = -1;
>> struct dma_fence *entry;
>> - unsigned long index;
>> - u32 id = 0;
>> - int ret;
>> if (!fence)
>> return 0;
>> @@ -896,11 +894,13 @@ int drm_sched_job_add_dependency(struct drm_sched_job
>> *job,
>> return 0;
>> }
>> - ret = xa_alloc(&job->dependencies, &id, fence, xa_limit_32b,
>> GFP_KERNEL);
>> - if (ret != 0)
>> + entry = xa_store(&job->dependencies, index + 1, fence, GFP_KERNEL);
>
> From the code it looks index does not "move" for NULL slots?
Correct, but I just found out that the macro initializes index to zero, so that
approach also doesn't work.
*sigh* going to look into this again tomorrow. It looks like this use case is
somehow not well supported at all by xarray.
Regards,
Christian.
>
> That is, if someone:
>
> 1) Preallocates one entry, when trying to populate it index will be -1 after
> xa_for_each?
>
> 2) Add one, preallocate one, then add one more - index will be 0 after
> xa_for_each?
>
> Regards,
>
> Tvrtko
>
>> + if (xa_is_err(entry))
>> dma_fence_put(fence);
>> + else
>> + WARN_ON(entry);
>> - return ret;
>> + return xa_err(entry);
>> }
>> EXPORT_SYMBOL(drm_sched_job_add_dependency);
>>
>
