Hi, Christian, On Tue, 2024-04-16 at 13:55 +0200, Christian König wrote: > While patches 1-4 look good from a high level I still think it needs > some prerequisite and re-ordering. > > First of all make all the cleanups separate patches. In other words > that > ttm_resource_manager_next() takes only the cursor as argument, adding > ttm_resource_cursor_fini()/ttm_resource_cursor_fini_locked() as one > patch and then ttm_lru_bulk_move_init()/ttm_lru_bulk_move_fini() as > second. Yes, I can take a look at that. I think the shortening of the argument list of ttm_resource_manager_next() makes sense as a separate cleanup. The other two are needed because of the changes introduced in the respective patches. I could of course add stubs of these functions before the patch that currently introduce them if needed, but don't really see the point. What do you think. > > With that done I think we should first switch over TTM and all > drivers > using it to drm_exec as part of it's context object. So are you ok with adding an optional drm_exec pointer in the ttm_operation_ctx for this? (That was my plan moving forward). However, when that has been added, I think it makes sense to leave to the driver author to port their validation loops and bo allocation over to using drm_exec. While we made sure the drm_exec object was indeed passed to the validation helper in the drm_gpuvm code, I'm not sure everybody actually includes their validation and bo allocation (for example page-table-bos) in their drm_exec while_not_all_locked() loop, and I think it's reasonable to require the "port the driver over" to be an optional but strongly recommended driver effort. If the driver sets ctx->drm_exec to NULL, it will fallback to current behaviour. > > Then I would switch over to using LRU hitches for both swapping and > eviction. > > And when that's finally done we can take a look into the partial > shmem > swapping :) > > And Felix is really (and mean *really*) looking forward to the > partial > shmem swapping as well. While the LRU walker helper introduced in patch 8 has drm_exec support, shrinkers don't require it, since they are always trylocking. (However being able to "evict" system to swap directly in the validation stage using drm_exec locking is probably something we should support). That's why I opted for implementing shrinking before exhaustive eviction. But if you insist we can do it the other way around. Most of what's needed is already in the patches. /Thomas > > Regards, > Christian. > > Am 16.04.24 um 12:07 schrieb Thomas Hellström: > > This series implements TTM shrinker / eviction helpers and an xe bo > > shrinker. It builds on two previous series, *and obsoletes these*. > > First > > > > https://www.mail-archive.com/dri-devel@xxxxxxxxxxxxxxxxxxxxx/msg484425.html > > > > for patch 1-4, which IMO still could be reviewed and pushed as a > > separate series. > > > > Second the previous TTM shrinker series > > > > https://lore.kernel.org/linux-mm/b7491378-defd-4f1c-31e2-29e4c77e2d67@xxxxxxx/T/ > > > > Where the comment about layering > > https://lore.kernel.org/linux-mm/b7491378-defd-4f1c-31e2-29e4c77e2d67@xxxxxxx/T/#ma918844aa8a6efe8768fdcda0c6590d5c93850c9 > > > > now addressed, and this version also implements shmem objects for > > backup > > rather than direct swap-cache insertions, which was used in the > > previuos > > series. It turns out that with per-page backup / shrinking, shmem > > objects > > appears to work just as well as direct swap-cache insertions with > > the > > added benefit that was introduced in the previous TTM shrinker > > series to > > avoid running out of swap entries isn't really needed. > > > > In any case, patch 1-4 are better described in their separate > > series. > > (RFC is removed for those). > > > > Patch 5 could in theory be skipped but introduces a possibility to > > easily > > add or test multiple backup backends, like the direct swap-cache > > insertion or even files into fast dedicated nvme storage for for > > example. > > > > Patch 6 introduces helpers in the ttm_pool code for page-by-page > > shrinking > > and recovery. It avoids having to temporarily allocate a huge > > amount of > > memory to be able to shrink a buffer object. It also introduces the > > possibility to immediately write-back pages if needed, since that > > tends > > to be a bit delayed when left to kswapd. > > > > Patch 7 Adds a simple error injection to the above code to help > > increase > > test coverage. > > > > Patch 8 introduces a LRU walk helper for eviction and shrinking. > > It's > > currently xe-only but not xe-specific and can easily be moved to > > TTM when > > used by more than one driver or when eviction is implemented using > > it. > > > > Patch 9 introduces a helper callback for shrinking (Also ready to > > be > > moved to TTM) and an xe-specific shrinker implementation. It also > > adds a kunit test to test the shrinker functionality by trying to > > allocate twice the available amount of RAM as buffer objects. If > > there > > is no swap-space available, the buffer objects are marked > > purgeable. > > > > v2: > > - Squash obsolete revision history in the patch commit messages. > > - Fix a couple of review comments by Christian > > - Don't store the mem_type in the TTM managers but in the > > resource cursor. > > - Rename introduced TTM *back_up* function names to *backup* > > - Add ttm pool recovery fault injection. > > - Shrinker xe kunit test > > - Various bugfixes > > > > Cc: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx> > > Cc: Christian König <christian.koenig@xxxxxxx> > > Cc: <dri-devel@xxxxxxxxxxxxxxxxxxxxx> > > > > Thomas Hellström (8): > > drm/ttm: Allow TTM LRU list nodes of different types > > drm/ttm: Use LRU hitches > > drm/ttm, drm/amdgpu, drm/xe: Consider hitch moves within bulk > > sublist > > moves > > drm/ttm: Allow continued swapout after -ENOSPC falure > > drm/ttm: Add a virtual base class for graphics memory backup > > drm/ttm/pool: Provide a helper to shrink pages. > > drm/xe, drm/ttm: Provide a generic LRU walker helper > > drm/xe: Add a shrinker for xe bos > > > > drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 4 + > > drivers/gpu/drm/ttm/Makefile | 2 +- > > drivers/gpu/drm/ttm/ttm_backup_shmem.c | 137 +++++++++ > > drivers/gpu/drm/ttm/ttm_bo.c | 1 + > > drivers/gpu/drm/ttm/ttm_device.c | 33 ++- > > drivers/gpu/drm/ttm/ttm_pool.c | 391 > > ++++++++++++++++++++++++- > > drivers/gpu/drm/ttm/ttm_resource.c | 231 ++++++++++++--- > > drivers/gpu/drm/ttm/ttm_tt.c | 34 +++ > > drivers/gpu/drm/xe/Makefile | 2 + > > drivers/gpu/drm/xe/xe_bo.c | 123 ++++++-- > > drivers/gpu/drm/xe/xe_bo.h | 3 + > > drivers/gpu/drm/xe/xe_device.c | 8 + > > drivers/gpu/drm/xe/xe_device_types.h | 2 + > > drivers/gpu/drm/xe/xe_shrinker.c | 237 +++++++++++++++ > > drivers/gpu/drm/xe/xe_shrinker.h | 18 ++ > > drivers/gpu/drm/xe/xe_ttm_helpers.c | 224 ++++++++++++++ > > drivers/gpu/drm/xe/xe_ttm_helpers.h | 63 ++++ > > drivers/gpu/drm/xe/xe_vm.c | 4 + > > include/drm/ttm/ttm_backup.h | 136 +++++++++ > > include/drm/ttm/ttm_device.h | 2 + > > include/drm/ttm/ttm_pool.h | 4 + > > include/drm/ttm/ttm_resource.h | 96 +++++- > > include/drm/ttm/ttm_tt.h | 19 ++ > > 23 files changed, 1683 insertions(+), 91 deletions(-) > > create mode 100644 drivers/gpu/drm/ttm/ttm_backup_shmem.c > > create mode 100644 drivers/gpu/drm/xe/xe_shrinker.c > > create mode 100644 drivers/gpu/drm/xe/xe_shrinker.h > > create mode 100644 drivers/gpu/drm/xe/xe_ttm_helpers.c > > create mode 100644 drivers/gpu/drm/xe/xe_ttm_helpers.h > > create mode 100644 include/drm/ttm/ttm_backup.h > > >
