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

[Nirmoy Das <nirmoy.das@xxxxxxxxxxxxxxx>]

On 9/25/2023 3:23 PM, Andrzej Hajda wrote:
> On 22.09.2023 14:35, Nirmoy Das wrote:
> > From: Jonathan Cavitt <jonathan.cavitt@xxxxxxxxx>
> >
> > 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@xxxxxxxxx>
> > Signed-off-by: Nirmoy Das <nirmoy.das@xxxxxxxxx>
> > ---
> >   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@xxxxxxxxx>

Thanks,

Nirmoy

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