Re: [PATCH V19 00/15] Add memory page offlining support

[Matthew Brost <matthew.brost@intel.com>]

On Mon, Aug 31, 2026 at 10:04:48AM -0400, Rodrigo Vivi wrote:
> On Mon, Aug 31, 2026 at 12:19:42PM +0530, Tejas Upadhyay wrote:
> > This functionality represents a significant step in making
> > the xe driver gracefully handle hardware memory degradation.
> > By integrating with the DRM Buddy allocator, the driver
> > can permanently "carve out" faulty memory so it isn't reused
> > by subsequent allocations.
> > 
> > IGT tests for testing this via injecting simple single address and
> > duplicate address fault to unit test functionality:
> > https://patchwork.freedesktop.org/patch/748439/?series=170555&rev=2
> > 
> > v19:
> > - Sashiko review comment closure
> 
> I was going to push this series, but I see that there are still
> many Sashiko comments that seems valid in this version.
> 

Let me also take a final pass look at this too before pushing it too.

Last I looked the large number of Sashiko comments was my concern.

I'll make this priority to look a bit later today.

Matt

> Could you please comment one by one at least documenting why we
> are ignoring those? (I mean, only for the ones that are not pre-existing)
> 
> Thanks,
> Rodrigo.
> 
> > - Sliting of making xe_bo_ttm_purge() export and NULL handling
> > - Remove redundant code in xe_ttm_vram_reserve_page_at_addr()
> > - Resolve nit comments provided in configfs and debugfs
> > v18:
> > - Splitting out the sysfs patch; it will come later once it is redesigned
> > - Address sashiko reivew comments
> > - Add debugfs and adjust igt tests and fault injection
> > v17:
> > - Rebase on drm-tip
> > - Enforce CONFIG_FAULT_INJECTION_DEBUG_FS for fault inject
> > v16:
> > - Correct sysfs patches with moving code with rcu lock
> > - In case purge fail let next alloc decide final failure
> > - Remove addr_to_block API, its being pulled from drm-tip
> > - Remove some unused code and replace where existing API can be used
> > v15:
> > - Split few big patches into small
> > - Avoid vram_mgr lock in sysfs
> > - fix missing queue_pages counter increment
> > v14:
> > - Solve sashiko reviews
> > - Remove SOFT->HARD offline patch, decision is taken based on -EEXIST
> > - Dump gpu buddy allocated patch dropped
> > v13:
> > - Add fault inject and remove standlone debugfs
> > v12:
> > - Fix Sashiko review comments
> > v11:
> > - Add BAN reason for UMD to know about offlining
> > - Add support for soft offline mode
> > - Rebase and remove dummy lockdep annotation patch, as it merged from upstream
> > v10:
> > - Remove RFC
> > v7:
> > - Improve debugfs warning messages
> > - Use scope_guard for locking(MattB)
> > - Adapt addition of queue member of LRC BO(MattB)
> > - Extend and use xe_ttm_bo_purge API for vram pages(MattB)
> > - Handle dma_buf_map requests for native and remote(MattB)
> > - Address if in never initialized block, set block to NULL
> > - Add lockdep in gpu buddy (MattB)
> > - Correct allocated_addr_to_block logic (MattA)
> > V6:
> > - Add more specific tests to noncritical bo sections
> > - Handle smooth exit of user created exec queues
> > - Break code and make purge specific static API
> > V5:
> > - Sysfs "max_pages" addition
> > - Reset block->private NULL post purge
> > - Remove wedge, return -EIO to system controller will initiate reset
> > - Add debugfs tests to trigger different test scenarios manually and via igt
> > - Rename addr_to_tbo to addr_to_block and move under gpu/buddy.c
> > V4: API reworks, add configfs for policy reservation and apply config everywhere
> > V3: use res_to_mem_region to avoid use of block->private (MattA)
> > V2:
> > - some fixes and clean up on errors
> > - Added xe_vram_addr_to_region helper to avoid other use of block->private(MattB)
> > 
> > Tejas Upadhyay (15):
> >   drm/xe: Link VRAM object with gpu buddy
> >   drm/xe: Link LRC BO and its execution Queue
> >   drm/xe: Export xe_ttm_bo_purge()
> >   drm/xe: Handle NULL resource and allow purging of VRAM pages
> >   drm/xe/bo: Make xe_bo_is_user() public
> >   drm/xe: Guard teardown paths against purged BOs
> >   drm/xe/vram: Extract buddy alloc and free helpers
> >   drm/xe/vram: Add page offline data structures and lifecycle
> >   drm/xe/vram: Add VRAM page offline fault handler
> >   drm/xe/configfs: Add disable_vram_page_offline attribute
> >   drm/xe/ras: Cache disable_vram_page_offline policy at init
> >   drm/xe/vram: Check disable_vram_page_offline policy in fault handler
> >   drm/xe: Expose bad VRAM pages via debugfs
> >   drm/xe/uapi: Expose ban reason in EXEC_QUEUE_GET_PROPERTY_BAN
> >   drm/xe: Add fault-inject based VRAM page offline injection
> > 
> >  drivers/gpu/drm/xe/xe_bo.c                 |  25 +-
> >  drivers/gpu/drm/xe/xe_bo.h                 |   2 +
> >  drivers/gpu/drm/xe/xe_bo_types.h           |   3 +
> >  drivers/gpu/drm/xe/xe_configfs.c           |  72 ++-
> >  drivers/gpu/drm/xe/xe_configfs.h           |   2 +
> >  drivers/gpu/drm/xe/xe_debugfs.c            |  51 +++
> >  drivers/gpu/drm/xe/xe_debugfs.h            |   2 +
> >  drivers/gpu/drm/xe/xe_dma_buf.c            |   3 +
> >  drivers/gpu/drm/xe/xe_drm_ras_types.h      |   3 +
> >  drivers/gpu/drm/xe/xe_exec_queue.c         |  14 +-
> >  drivers/gpu/drm/xe/xe_exec_queue_types.h   |   7 +-
> >  drivers/gpu/drm/xe/xe_execlist.c           |   4 +-
> >  drivers/gpu/drm/xe/xe_guc_submit.c         |  36 +-
> >  drivers/gpu/drm/xe/xe_lrc.c                |   1 +
> >  drivers/gpu/drm/xe/xe_ras.c                |   9 +
> >  drivers/gpu/drm/xe/xe_ttm_vram_mgr.c       | 510 ++++++++++++++++++++-
> >  drivers/gpu/drm/xe/xe_ttm_vram_mgr.h       |   4 +
> >  drivers/gpu/drm/xe/xe_ttm_vram_mgr_types.h |  40 ++
> >  include/uapi/drm/xe_drm.h                  |  18 +-
> >  19 files changed, 760 insertions(+), 46 deletions(-)
> > 
> > -- 
> > 2.52.0
> >