Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider: - [High] The logic change silently overrides `trylock_only` and `no_wait_gpu` flags when `ctx->exec` is provided, forcing blocking locks instead of trylocks. --
commit 5fb376340fb1686ce3b629a364137351ecc0b343 Author: Natalie Vock <[email protected]> drm/ttm: support using drm_exec during eviction v4 Allow specifying a drm_exec object in TTMs operation context which is used to lock objects during eviction. > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c > b/drivers/gpu/drm/ttm/ttm_bo_util.c > index a53b25e8c2967..96699532817c2 100644 > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c [ ... ] > @@ -837,6 +838,8 @@ static bool ttm_lru_walk_trylock(struct ttm_bo_lru_cursor > *curs, > struct ttm_operation_ctx *ctx = curs->arg->ctx; > > curs->needs_unlock = false; > + if (ctx->exec) > + return false; [Severity: High] Does returning false here when ctx->exec is set force the walk to bypass trylocking and push the logic into a blocking fallback? > > if (dma_resv_trylock(bo->base.resv)) { > curs->needs_unlock = true; [ ... ] > @@ -857,7 +860,9 @@ static int ttm_lru_walk_ticketlock(struct > ttm_bo_lru_cursor *curs, > struct ttm_lru_walk_arg *arg = curs->arg; > int ret; > > - if (arg->ctx->interruptible) > + if (arg->ctx->exec) > + ret = drm_exec_lock_obj_report_dup(arg->ctx->exec, &bo->base); [Severity: High] Does this perform a blocking WW mutex lock via drm_exec, completely ignoring the trylock_only intent of the caller? > + else if (arg->ctx->interruptible) > ret = dma_resv_lock_interruptible(bo->base.resv, arg->ticket); > else > ret = dma_resv_lock(bo->base.resv, arg->ticket); [ ... ] > @@ -1016,8 +1030,8 @@ __ttm_bo_lru_cursor_next(struct ttm_bo_lru_cursor *curs) > if (ttm_lru_walk_trylock(curs, bo)) { > bo_locked = true; > > - } else if (!arg->ticket || arg->ctx->no_wait_gpu || > - arg->trylock_only) { > + } else if ((!arg->ticket || arg->ctx->no_wait_gpu || > + arg->trylock_only) && !arg->ctx->exec) { [Severity: High] Does negating the non-blocking flags when ctx->exec is present force the walk to fall through to a blocking lock attempt? This appears to silently override the trylock_only and no_wait_gpu flags. When amdgpu_cs_bo_validate() triggers TTM eviction under memory pressure, it passes an operation context with ctx->exec set. ttm_bo_evict_first() initiates its first pass with trylock_only = true to find an idle buffer. Because of these changes, the walk bypasses the trylock_only check and falls through to ttm_lru_walk_ticketlock(), which calls drm_exec_lock_obj_report_dup() and performs a blocking WW mutex lock. Could this cause the eviction to block and wait on the first busy buffer in the LRU instead of skipping it, potentially breaking the two-pass eviction strategy and leading to unnecessary command submission backoffs or serialization of independent workloads? > spin_unlock(lru_lock); > ttm_bo_put(bo); > spin_lock(lru_lock); -- Sashiko AI review ยท https://sashiko.dev/#/patchset/[email protected]?part=9
