GPU drivers need this in their shrinkers, to be able to throw out mmap'ed buffers. Note that we also need dma_resv_lock in shrinkers, but that loop is resolved by trylocking in shrinkers.
So full hierarchy is now (ignore some of the other branches we already have primed): mmap_read_lock -> dma_resv -> shrinkers -> i_mmap_lock_write I hope that's not inconsistent with anything mm or fs does, adding relevant people. Signed-off-by: Daniel Vetter <[email protected]> Cc: Sumit Semwal <[email protected]> Cc: "Christian König" <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Dave Chinner <[email protected]> Cc: Qian Cai <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Thomas Hellström (Intel) <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Jason Gunthorpe <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Maarten Lankhorst <[email protected]> --- drivers/dma-buf/dma-resv.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c index 0e6675ec1d11..9678162a4ac5 100644 --- a/drivers/dma-buf/dma-resv.c +++ b/drivers/dma-buf/dma-resv.c @@ -104,12 +104,14 @@ static int __init dma_resv_lockdep(void) struct mm_struct *mm = mm_alloc(); struct ww_acquire_ctx ctx; struct dma_resv obj; + struct address_space mapping; int ret; if (!mm) return -ENOMEM; dma_resv_init(&obj); + address_space_init_once(&mapping); mmap_read_lock(mm); ww_acquire_init(&ctx, &reservation_ww_class); @@ -117,6 +119,9 @@ static int __init dma_resv_lockdep(void) if (ret == -EDEADLK) dma_resv_lock_slow(&obj, &ctx); fs_reclaim_acquire(GFP_KERNEL); + /* for unmap_mapping_range on trylocked buffer objects in shrinkers */ + i_mmap_lock_write(&mapping); + i_mmap_unlock_write(&mapping); #ifdef CONFIG_MMU_NOTIFIER lock_map_acquire(&__mmu_notifier_invalidate_range_start_map); __dma_fence_might_wait(); -- 2.27.0 _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
