Use fault-injection to test partial TTM swapout and interrupted swapin.
Return -EINTR for swapin to test the callers ability to handle and
restart the swapin, and on swapout perform a partial swapout to test that
the swapin and release_shrunken functionality.
v8:
- Use the core fault-injection system.
v9:
- Fix compliation failure for !CONFIG_FAULT_INJECTION
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Somalapuram Amaranath <Amaranath.Somalapuram@xxxxxxx>
Cc: Matthew Brost <matthew.brost@xxxxxxxxx>
Cc: <dri-devel@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Reviewed-by: Matthew Brost <matthew.brost@xxxxxxxxx> #v7
---
drivers/gpu/drm/ttm/ttm_pool.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_pool.c b/drivers/gpu/drm/ttm/ttm_pool.c
index ffb7abf52bab..83b10706ba89 100644
--- a/drivers/gpu/drm/ttm/ttm_pool.c
+++ b/drivers/gpu/drm/ttm/ttm_pool.c
@@ -48,6 +48,13 @@
#include "ttm_module.h"
+#ifdef CONFIG_FAULT_INJECTION
+#include <linux/fault-inject.h>
+static DECLARE_FAULT_ATTR(backup_fault_inject);
+#else
+#define should_fail(...) false
+#endif
+
/**
* struct ttm_pool_dma - Helper object for coherent DMA mappings
*
@@ -514,6 +521,12 @@ static int ttm_pool_restore_commit(struct ttm_pool_tt_restore *restore,
if (ttm_backup_page_ptr_is_handle(p)) {
unsigned long handle = ttm_backup_page_ptr_to_handle(p);
+ if (IS_ENABLED(CONFIG_FAULT_INJECTION) && ctx->interruptible &&
+ should_fail(&backup_fault_inject, 1)) {
+ ret = -EINTR;
+ break;
+ }
+
if (handle == 0) {
restore->restored_pages++;
continue;
@@ -1007,7 +1020,13 @@ long ttm_pool_backup(struct ttm_pool *pool, struct ttm_tt *tt,
alloc_gfp = GFP_KERNEL | __GFP_HIGH | __GFP_NOWARN | __GFP_RETRY_MAYFAIL;
- for (i = 0; i < tt->num_pages; ++i) {
+ num_pages = tt->num_pages;
+
+ /* Pretend doing fault injection by shrinking only half of the pages. */
+ if (IS_ENABLED(CONFIG_FAULT_INJECTION) && should_fail(&backup_fault_inject, 1))
+ num_pages = DIV_ROUND_UP(num_pages, 2);
+
+ for (i = 0; i < num_pages; ++i) {
s64 shandle;
page = tt->pages[i];
@@ -1293,6 +1312,10 @@ int ttm_pool_mgr_init(unsigned long num_pages)
&ttm_pool_debugfs_globals_fops);
debugfs_create_file("page_pool_shrink", 0400, ttm_debugfs_root, NULL,
&ttm_pool_debugfs_shrink_fops);
+#ifdef CONFIG_FAULT_INJECTION
+ fault_create_debugfs_attr("backup_fault_inject", ttm_debugfs_root,
+ &backup_fault_inject);
+#endif
#endif
mm_shrinker = shrinker_alloc(0, "drm-ttm_pool");
--
2.47.1
