Messages in this thread | | | Date | Wed, 16 Mar 2022 13:19:32 +0000 | Subject | Re: [RFC PATCH 5/7] drm/ttm: add range busy check for range manager | From | Robert Beckett <> |
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On 16/03/2022 09:54, Christian König wrote: > Am 15.03.22 um 19:04 schrieb Robert Beckett: >> RFC: do we want this to become a generic interface in >> ttm_resource_manager_func? >> >> RFC: would we prefer a different interface? e.g. >> for_each_resource_in_range or for_each_bo_in_range > > Well completely NAK to that. Why do you need that? > > The long term goal is to completely remove the range checks from TTM > instead.
ah, I did not know that. I wanted it just to enable parity with a selftest that checks whether a range is allocated before initializing a given range with test data behind the allocator's back. It needs to check the range so that it doesn't destroy in use data.
I suppose we could add another drm_mm range tracker just for testing and shadow track each allocation in the range, but that seemed like a lot of extra infrastructure for no general runtime use.
would you mind explaining the rationale for removing range checks? It seems to me like a natural fit for a memory manager
> > Regards, > Christian. > >> >> Signed-off-by: Robert Beckett <bob.beckett@collabora.com> >> --- >> drivers/gpu/drm/ttm/ttm_range_manager.c | 21 +++++++++++++++++++++ >> include/drm/ttm/ttm_range_manager.h | 3 +++ >> 2 files changed, 24 insertions(+) >> >> diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c >> b/drivers/gpu/drm/ttm/ttm_range_manager.c >> index 8cd4f3fb9f79..5662627bb933 100644 >> --- a/drivers/gpu/drm/ttm/ttm_range_manager.c >> +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c >> @@ -206,3 +206,24 @@ int ttm_range_man_fini_nocheck(struct ttm_device >> *bdev, >> return 0; >> } >> EXPORT_SYMBOL(ttm_range_man_fini_nocheck); >> + >> +/** >> + * ttm_range_man_range_busy - Check whether anything is allocated >> with a range >> + * >> + * @man: memory manager to check >> + * @fpfn: first page number to check >> + * @lpfn: last page number to check >> + * >> + * Return: true if anything allocated within the range, false otherwise. >> + */ >> +bool ttm_range_man_range_busy(struct ttm_resource_manager *man, >> + unsigned fpfn, unsigned lpfn) >> +{ >> + struct ttm_range_manager *rman = to_range_manager(man); >> + struct drm_mm *mm = &rman->mm; >> + >> + if (__drm_mm_interval_first(mm, PFN_PHYS(fpfn), PFN_PHYS(lpfn + >> 1) - 1)) >> + return true; >> + return false; >> +} >> +EXPORT_SYMBOL(ttm_range_man_range_busy); >> diff --git a/include/drm/ttm/ttm_range_manager.h >> b/include/drm/ttm/ttm_range_manager.h >> index 7963b957e9ef..86794a3f9101 100644 >> --- a/include/drm/ttm/ttm_range_manager.h >> +++ b/include/drm/ttm/ttm_range_manager.h >> @@ -53,4 +53,7 @@ static __always_inline int ttm_range_man_fini(struct >> ttm_device *bdev, >> BUILD_BUG_ON(__builtin_constant_p(type) && type >= >> TTM_NUM_MEM_TYPES); >> return ttm_range_man_fini_nocheck(bdev, type); >> } >> + >> +bool ttm_range_man_range_busy(struct ttm_resource_manager *man, >> + unsigned fpfn, unsigned lpfn); >> #endif >
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