The shrinker based approach still has some flaws. Especially that we need temporary pages to free up the pages allocated to the driver is problematic in a shrinker.
Signed-off-by: Christian König christian.koenig@amd.com Acked-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/ttm/ttm_device.c | 14 ++-- drivers/gpu/drm/ttm/ttm_tt.c | 112 ++++++++++++------------------- include/drm/ttm/ttm_tt.h | 3 +- 3 files changed, 53 insertions(+), 76 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_device.c b/drivers/gpu/drm/ttm/ttm_device.c index 8e821cddf81c..9b787b3caeb5 100644 --- a/drivers/gpu/drm/ttm/ttm_device.c +++ b/drivers/gpu/drm/ttm/ttm_device.c @@ -53,7 +53,6 @@ static void ttm_global_release(void) goto out;
ttm_pool_mgr_fini(); - ttm_tt_mgr_fini();
__free_page(glob->dummy_read_page); memset(glob, 0, sizeof(*glob)); @@ -64,7 +63,7 @@ static void ttm_global_release(void) static int ttm_global_init(void) { struct ttm_global *glob = &ttm_glob; - unsigned long num_pages; + unsigned long num_pages, num_dma32; struct sysinfo si; int ret = 0;
@@ -78,8 +77,15 @@ static int ttm_global_init(void) * system memory. */ num_pages = ((u64)si.totalram * si.mem_unit) >> PAGE_SHIFT; - ttm_pool_mgr_init(num_pages * 50 / 100); - ttm_tt_mgr_init(); + num_pages /= 2; + + /* But for DMA32 we limit ourself to only use 2GiB maximum. */ + num_dma32 = (u64)(si.totalram - si.totalhigh) * si.mem_unit + >> PAGE_SHIFT; + num_dma32 = min(num_dma32, 2UL << (30 - PAGE_SHIFT)); + + ttm_pool_mgr_init(num_pages); + ttm_tt_mgr_init(num_pages, num_dma32);
glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c index 95b5cff25f4c..7dcd3fb69495 100644 --- a/drivers/gpu/drm/ttm/ttm_tt.c +++ b/drivers/gpu/drm/ttm/ttm_tt.c @@ -40,8 +40,18 @@
#include "ttm_module.h"
-static struct shrinker mm_shrinker; -static atomic_long_t swapable_pages; +static unsigned long ttm_pages_limit; + +MODULE_PARM_DESC(pages_limit, "Limit for the allocated pages"); +module_param_named(pages_limit, ttm_pages_limit, ulong, 0644); + +static unsigned long ttm_dma32_pages_limit; + +MODULE_PARM_DESC(dma32_pages_limit, "Limit for the allocated DMA32 pages"); +module_param_named(dma32_pages_limit, ttm_dma32_pages_limit, ulong, 0644); + +static atomic_long_t ttm_pages_allocated; +static atomic_long_t ttm_dma32_pages_allocated;
/* * Allocates a ttm structure for the given BO. @@ -294,8 +304,6 @@ static void ttm_tt_add_mapping(struct ttm_device *bdev, struct ttm_tt *ttm)
for (i = 0; i < ttm->num_pages; ++i) ttm->pages[i]->mapping = bdev->dev_mapping; - - atomic_long_add(ttm->num_pages, &swapable_pages); }
int ttm_tt_populate(struct ttm_device *bdev, @@ -309,12 +317,25 @@ int ttm_tt_populate(struct ttm_device *bdev, if (ttm_tt_is_populated(ttm)) return 0;
+ atomic_long_add(ttm->num_pages, &ttm_pages_allocated); + if (bdev->pool.use_dma32) + atomic_long_add(ttm->num_pages, &ttm_dma32_pages_allocated); + + while (atomic_long_read(&ttm_pages_allocated) > ttm_pages_limit || + atomic_long_read(&ttm_dma32_pages_allocated) > + ttm_dma32_pages_limit) { + + ret = ttm_global_swapout(ctx, GFP_KERNEL); + if (ret) + goto error; + } + if (bdev->funcs->ttm_tt_populate) ret = bdev->funcs->ttm_tt_populate(bdev, ttm, ctx); else ret = ttm_pool_alloc(&bdev->pool, ttm, ctx); if (ret) - return ret; + goto error;
ttm_tt_add_mapping(bdev, ttm); ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED; @@ -327,6 +348,12 @@ int ttm_tt_populate(struct ttm_device *bdev, }
return 0; + +error: + atomic_long_sub(ttm->num_pages, &ttm_pages_allocated); + if (bdev->pool.use_dma32) + atomic_long_sub(ttm->num_pages, &ttm_dma32_pages_allocated); + return ret; } EXPORT_SYMBOL(ttm_tt_populate);
@@ -342,12 +369,9 @@ static void ttm_tt_clear_mapping(struct ttm_tt *ttm) (*page)->mapping = NULL; (*page++)->index = 0; } - - atomic_long_sub(ttm->num_pages, &swapable_pages); }
-void ttm_tt_unpopulate(struct ttm_device *bdev, - struct ttm_tt *ttm) +void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm) { if (!ttm_tt_is_populated(ttm)) return; @@ -357,76 +381,24 @@ void ttm_tt_unpopulate(struct ttm_device *bdev, bdev->funcs->ttm_tt_unpopulate(bdev, ttm); else ttm_pool_free(&bdev->pool, ttm); - ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED; -} - -/* As long as pages are available make sure to release at least one */ -static unsigned long ttm_tt_shrinker_scan(struct shrinker *shrink, - struct shrink_control *sc) -{ - struct ttm_operation_ctx ctx = { - .no_wait_gpu = false - }; - int ret; - - ret = ttm_global_swapout(&ctx, GFP_NOFS); - return ret < 0 ? SHRINK_EMPTY : ret; -} - -/* Return the number of pages available or SHRINK_EMPTY if we have none */ -static unsigned long ttm_tt_shrinker_count(struct shrinker *shrink, - struct shrink_control *sc) -{ - unsigned long num_pages; - - num_pages = atomic_long_read(&swapable_pages); - return num_pages ? num_pages : SHRINK_EMPTY; -}
-#ifdef CONFIG_DEBUG_FS + atomic_long_sub(ttm->num_pages, &ttm_pages_allocated); + if (bdev->pool.use_dma32) + atomic_long_sub(ttm->num_pages, &ttm_dma32_pages_allocated);
-/* Test the shrinker functions and dump the result */ -static int ttm_tt_debugfs_shrink_show(struct seq_file *m, void *data) -{ - struct shrink_control sc = { .gfp_mask = GFP_KERNEL }; - - fs_reclaim_acquire(GFP_KERNEL); - seq_printf(m, "%lu/%lu\n", ttm_tt_shrinker_count(&mm_shrinker, &sc), - ttm_tt_shrinker_scan(&mm_shrinker, &sc)); - fs_reclaim_release(GFP_KERNEL); - - return 0; + ttm->page_flags &= ~TTM_PAGE_FLAG_PRIV_POPULATED; } -DEFINE_SHOW_ATTRIBUTE(ttm_tt_debugfs_shrink); - -#endif - -
/** * ttm_tt_mgr_init - register with the MM shrinker * * Register with the MM shrinker for swapping out BOs. */ -int ttm_tt_mgr_init(void) +void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages) { -#ifdef CONFIG_DEBUG_FS - debugfs_create_file("tt_shrink", 0400, ttm_debugfs_root, NULL, - &ttm_tt_debugfs_shrink_fops); -#endif - - mm_shrinker.count_objects = ttm_tt_shrinker_count; - mm_shrinker.scan_objects = ttm_tt_shrinker_scan; - mm_shrinker.seeks = 1; - return register_shrinker(&mm_shrinker); -} + if (!ttm_pages_limit) + ttm_pages_limit = num_pages;
-/** - * ttm_tt_mgr_fini - unregister our MM shrinker - * - * Unregisters the MM shrinker. - */ -void ttm_tt_mgr_fini(void) -{ - unregister_shrinker(&mm_shrinker); + if (!ttm_dma32_pages_limit) + ttm_dma32_pages_limit = num_dma32_pages; } diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index 069f8130241a..134d09ef7766 100644 --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -157,8 +157,7 @@ int ttm_tt_populate(struct ttm_device *bdev, struct ttm_tt *ttm, struct ttm_oper */ void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm);
-int ttm_tt_mgr_init(void); -void ttm_tt_mgr_fini(void); +void ttm_tt_mgr_init(unsigned long num_pages, unsigned long num_dma32_pages);
#if IS_ENABLED(CONFIG_AGP) #include <linux/agp_backend.h>