From 9fab8a2ea0d39343da077eeaa386ceeba10ca316 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Wed, 9 Jan 2019 16:42:04 +0000 Subject: [PATCH] drm/i915: Removing polling for struct_mutex from vmap shrinker The wait-for-idle used from within the shrinker_lock_uninterruptible depends on the struct_mutex locking state being known and declared to i915_request_wait(). As it is conceivable that we reach the vmap notifier from underneath struct_mutex (and so keep on relying on the mutex_trylock_recursive), we should not blindly call i915_request_wait. In the process we can remove the dubious polling to acquire struct_mutex, and simply act, or not, on a successful trylock. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20190109164204.23935-2-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/i915_gem_shrinker.c | 35 ++++---------------------------- 1 file changed, 4 insertions(+), 31 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_shrinker.c b/drivers/gpu/drm/i915/i915_gem_shrinker.c index 8ad9519779cc..6cc2b964c955 100644 --- a/drivers/gpu/drm/i915/i915_gem_shrinker.c +++ b/drivers/gpu/drm/i915/i915_gem_shrinker.c @@ -385,31 +385,6 @@ i915_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc) return sc->nr_scanned ? freed : SHRINK_STOP; } -static bool -shrinker_lock_uninterruptible(struct drm_i915_private *i915, bool *unlock, - int timeout_ms) -{ - unsigned long timeout = jiffies + msecs_to_jiffies_timeout(timeout_ms); - - do { - if (i915_gem_wait_for_idle(i915, - 0, MAX_SCHEDULE_TIMEOUT) == 0 && - shrinker_lock(i915, 0, unlock)) - break; - - schedule_timeout_killable(1); - if (fatal_signal_pending(current)) - return false; - - if (time_after(jiffies, timeout)) { - pr_err("Unable to lock GPU to purge memory.\n"); - return false; - } - } while (1); - - return true; -} - static int i915_gem_shrinker_oom(struct notifier_block *nb, unsigned long event, void *ptr) { @@ -461,16 +436,14 @@ i915_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr struct i915_vma *vma, *next; unsigned long freed_pages = 0; bool unlock; - int ret; - if (!shrinker_lock_uninterruptible(i915, &unlock, 5000)) + if (!shrinker_lock(i915, 0, &unlock)) return NOTIFY_DONE; /* Force everything onto the inactive lists */ - ret = i915_gem_wait_for_idle(i915, - I915_WAIT_LOCKED, - MAX_SCHEDULE_TIMEOUT); - if (ret) + if (i915_gem_wait_for_idle(i915, + I915_WAIT_LOCKED, + MAX_SCHEDULE_TIMEOUT)) goto out; intel_runtime_pm_get(i915); -- 2.11.0