[Intel-gfx] [PATCH] drm/i915/gem: Make i915_gem_shrinker multi-gt aware

[Nirmoy Das]

On 9/25/2023 3:23 PM, Andrzej Hajda wrote:
> On 22.09.2023 14:35, Nirmoy Das wrote:
>> From: Jonathan Cavitt <jonathan.cavitt at intel.com>
>>
>> Where applicable, use for_each_gt instead of to_gt in the
>> i915_gem_shrinker functions to make them apply to more than just the
>> primary GT.  Specifically, this ensure i915_gem_shrink_all retires all
>> requests across all GTs, and this makes i915_gem_shrinker_vmap unmap
>> VMAs from all GTs.
>>
>> Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
>> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
>> ---
>>   drivers/gpu/drm/i915/gem/i915_gem_shrinker.c | 44 ++++++++++++--------
>>   1 file changed, 26 insertions(+), 18 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c 
>> b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>> index 214763942aa2..3ef1fd32f80a 100644
>> --- a/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>> +++ b/drivers/gpu/drm/i915/gem/i915_gem_shrinker.c
>> @@ -14,6 +14,7 @@
>>   #include <linux/vmalloc.h>
>>     #include "gt/intel_gt_requests.h"
>> +#include "gt/intel_gt.h"
>>     #include "i915_trace.h"
>>   @@ -119,7 +120,8 @@ i915_gem_shrink(struct i915_gem_ww_ctx *ww,
>>       intel_wakeref_t wakeref = 0;
>>       unsigned long count = 0;
>>       unsigned long scanned = 0;
>> -    int err = 0;
>> +    int err = 0, i = 0;
>> +    struct intel_gt *gt;
>>         /* CHV + VTD workaround use stop_machine(); need to trylock 
>> vm->mutex */
>>       bool trylock_vm = !ww && intel_vm_no_concurrent_access_wa(i915);
>> @@ -147,9 +149,11 @@ i915_gem_shrink(struct i915_gem_ww_ctx *ww,
>>        * what we can do is give them a kick so that we do not keep idle
>>        * contexts around longer than is necessary.
>>        */
>> -    if (shrink & I915_SHRINK_ACTIVE)
>> -        /* Retire requests to unpin all idle contexts */
>> -        intel_gt_retire_requests(to_gt(i915));
>> +    if (shrink & I915_SHRINK_ACTIVE) {
>> +        for_each_gt(gt, i915, i)
>> +            /* Retire requests to unpin all idle contexts */
>> +            intel_gt_retire_requests(to_gt(i915));
>
>
> to_gt(...) -> gt ?


Wow, a huge miss. Thanks will resend!

>
>
>> +    }
>>         /*
>>        * As we may completely rewrite the (un)bound list whilst 
>> unbinding
>> @@ -389,6 +393,8 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, 
>> unsigned long event, void *ptr
>>       struct i915_vma *vma, *next;
>>       unsigned long freed_pages = 0;
>>       intel_wakeref_t wakeref;
>> +    struct intel_gt *gt;
>> +    int i;
>>         with_intel_runtime_pm(&i915->runtime_pm, wakeref)
>>           freed_pages += i915_gem_shrink(NULL, i915, -1UL, NULL,
>> @@ -397,24 +403,26 @@ i915_gem_shrinker_vmap(struct notifier_block 
>> *nb, unsigned long event, void *ptr
>>                              I915_SHRINK_VMAPS);
>>         /* We also want to clear any cached iomaps as they wrap vmap */
>> -    mutex_lock(&to_gt(i915)->ggtt->vm.mutex);
>> -    list_for_each_entry_safe(vma, next,
>> -                 &to_gt(i915)->ggtt->vm.bound_list, vm_link) {
>> -        unsigned long count = i915_vma_size(vma) >> PAGE_SHIFT;
>> -        struct drm_i915_gem_object *obj = vma->obj;
>> -
>> -        if (!vma->iomap || i915_vma_is_active(vma))
>> -            continue;
>> +    for_each_gt(gt, i915, i) {
>> +        mutex_lock(&gt->ggtt->vm.mutex);
>> +        list_for_each_entry_safe(vma, next,
>> +                     &gt->ggtt->vm.bound_list, vm_link) {
>> +            unsigned long count = i915_vma_size(vma) >> PAGE_SHIFT;
>> +            struct drm_i915_gem_object *obj = vma->obj;
>> +
>> +            if (!vma->iomap || i915_vma_is_active(vma))
>> +                continue;
>>   -        if (!i915_gem_object_trylock(obj, NULL))
>> -            continue;
>> +            if (!i915_gem_object_trylock(obj, NULL))
>> +                continue;
>>   -        if (__i915_vma_unbind(vma) == 0)
>> -            freed_pages += count;
>> +            if (__i915_vma_unbind(vma) == 0)
>> +                freed_pages += count;
>>   -        i915_gem_object_unlock(obj);
>> +            i915_gem_object_unlock(obj);
>> +        }
>> +        mutex_unlock(&gt->ggtt->vm.mutex);
>>       }
>> -    mutex_unlock(&to_gt(i915)->ggtt->vm.mutex);
>
>
> This seems correct.
>
> With 1st stanza fixed:
> Reviewed-by: Andrzej Hajda <andrzej.hajda at intel.com>

Thanks,

Nirmoy

>
> Regards
> Andrzej
>
>
>>         *(unsigned long *)ptr += freed_pages;
>>       return NOTIFY_DONE;
>