From: Nicolas Frattaroli Date: Thu, 21 May 2026 13:51:15 +0000 (+0200) Subject: drm/panthor: Implement evicted status for GEM objects X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5715f1f1b9283d49956882d6d3f6d8113e02f609;p=thirdparty%2Fkernel%2Flinux.git drm/panthor: Implement evicted status for GEM objects For fdinfo to be able to fill its evicted counter with data, panthor needs to keep track of whether a GEM object has ever been reclaimed. Just checking whether the pages are resident isn't enough, as newly allocated objects also won't be resident. Do this with a new atomic_t member on panthor_gem_object. It's increased when an object gets evicted by the shrinker, and saturates at INT_MAX. This means that once an object has been evicted at least once, its reclaim counter will never return to 0. Due to this, it's possible to distinguish evicted non-resident pages from newly allocated non-resident pages by checking whether reclaimed_count is != 0 Also add a new column and status flag to the panthor gems debugfs: the column is the number of times an object has been evicted, whereas the flag indicates whether it currently is evicted. Reviewed-by: Steven Price Reviewed-by: Boris Brezillon Signed-off-by: Nicolas Frattaroli Link: https://patch.msgid.link/20260521-panthor-bo-reclaim-observability-v5-1-49313994da55@collabora.com Signed-off-by: Boris Brezillon --- diff --git a/drivers/gpu/drm/panthor/panthor_gem.c b/drivers/gpu/drm/panthor/panthor_gem.c index abe0c5bb1bca3..ec2abc6ce417d 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.c +++ b/drivers/gpu/drm/panthor/panthor_gem.c @@ -687,6 +687,8 @@ static void panthor_gem_evict_locked(struct panthor_gem_object *bo) if (drm_WARN_ON_ONCE(bo->base.dev, !bo->backing.pages)) return; + atomic_add_unless(&bo->reclaimed_count, 1, INT_MAX); + panthor_gem_dev_map_cleanup_locked(bo); panthor_gem_backing_cleanup_locked(bo); panthor_gem_update_reclaim_state_locked(bo, NULL); @@ -1590,6 +1592,7 @@ static void panthor_gem_debugfs_print_flag_names(struct seq_file *m) static const char * const gem_state_flags_names[] = { [PANTHOR_DEBUGFS_GEM_STATE_IMPORTED_BIT] = "imported", [PANTHOR_DEBUGFS_GEM_STATE_EXPORTED_BIT] = "exported", + [PANTHOR_DEBUGFS_GEM_STATE_EVICTED_BIT] = "evicted", }; static const char * const gem_usage_flags_names[] = { @@ -1620,6 +1623,7 @@ static void panthor_gem_debugfs_bo_print(struct panthor_gem_object *bo, { enum panthor_gem_reclaim_state reclaim_state = bo->reclaim_state; unsigned int refcount = kref_read(&bo->base.refcount); + int reclaimed_count = atomic_read(&bo->reclaimed_count); char creator_info[32] = {}; size_t resident_size; u32 gem_usage_flags = bo->debugfs.flags; @@ -1633,16 +1637,20 @@ static void panthor_gem_debugfs_bo_print(struct panthor_gem_object *bo, snprintf(creator_info, sizeof(creator_info), "%s/%d", bo->debugfs.creator.process_name, bo->debugfs.creator.tgid); - seq_printf(m, "%-32s%-16d%-16d%-16zd%-16zd0x%-16lx", + seq_printf(m, "%-32s%-16d%-16d%-11d%-16zd%-16zd0x%-16lx", creator_info, bo->base.name, refcount, + reclaimed_count, bo->base.size, resident_size, drm_vma_node_start(&bo->base.vma_node)); if (drm_gem_is_imported(&bo->base)) gem_state_flags |= PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED; + else if (!resident_size && reclaimed_count) + gem_state_flags |= PANTHOR_DEBUGFS_GEM_STATE_FLAG_EVICTED; + if (bo->base.dma_buf) gem_state_flags |= PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED; @@ -1666,8 +1674,8 @@ static void panthor_gem_debugfs_print_bos(struct panthor_device *ptdev, panthor_gem_debugfs_print_flag_names(m); - seq_puts(m, "created-by global-name refcount size resident-size file-offset state usage label\n"); - seq_puts(m, "----------------------------------------------------------------------------------------------------------------------------------------------\n"); + seq_puts(m, "created-by global-name refcount evictions size resident-size file-offset state usage label\n"); + seq_puts(m, "---------------------------------------------------------------------------------------------------------------------------------------------------------\n"); scoped_guard(mutex, &ptdev->gems.lock) { list_for_each_entry(bo, &ptdev->gems.node, debugfs.node) { @@ -1675,7 +1683,7 @@ static void panthor_gem_debugfs_print_bos(struct panthor_device *ptdev, } } - seq_puts(m, "==============================================================================================================================================\n"); + seq_puts(m, "=========================================================================================================================================================\n"); seq_printf(m, "Total size: %zd, Total resident: %zd, Total reclaimable: %zd\n", totals.size, totals.resident, totals.reclaimable); } diff --git a/drivers/gpu/drm/panthor/panthor_gem.h b/drivers/gpu/drm/panthor/panthor_gem.h index ae0491d0b1216..56d63137b4ebb 100644 --- a/drivers/gpu/drm/panthor/panthor_gem.h +++ b/drivers/gpu/drm/panthor/panthor_gem.h @@ -19,12 +19,16 @@ struct panthor_vm; enum panthor_debugfs_gem_state_flags { PANTHOR_DEBUGFS_GEM_STATE_IMPORTED_BIT = 0, PANTHOR_DEBUGFS_GEM_STATE_EXPORTED_BIT = 1, + PANTHOR_DEBUGFS_GEM_STATE_EVICTED_BIT = 2, /** @PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED: GEM BO is PRIME imported. */ PANTHOR_DEBUGFS_GEM_STATE_FLAG_IMPORTED = BIT(PANTHOR_DEBUGFS_GEM_STATE_IMPORTED_BIT), /** @PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED: GEM BO is PRIME exported. */ PANTHOR_DEBUGFS_GEM_STATE_FLAG_EXPORTED = BIT(PANTHOR_DEBUGFS_GEM_STATE_EXPORTED_BIT), + + /** @PANTHOR_DEBUGFS_GEM_STATE_FLAG_EVICTED: GEM BO is evicted to swap. */ + PANTHOR_DEBUGFS_GEM_STATE_FLAG_EVICTED = BIT(PANTHOR_DEBUGFS_GEM_STATE_EVICTED_BIT), }; enum panthor_debugfs_gem_usage_flags { @@ -172,6 +176,12 @@ struct panthor_gem_object { /** @reclaim_state: Cached reclaim state */ enum panthor_gem_reclaim_state reclaim_state; + /** + * @reclaimed_count: How many times object has been evicted to swap. + * The count saturates at %INT_MAX and will never wrap around to 0. + */ + atomic_t reclaimed_count; + /** * @exclusive_vm_root_gem: Root GEM of the exclusive VM this GEM object * is attached to.