Commit 025d2723 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/gem: Evict active GEM objects when necessary 



If we are under enough memory pressure, we should stall waiting for
active buffers to become idle in order to evict.

v2: Check for __GFP_ATOMIC before blocking

Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/496135/
Link: https://lore.kernel.org/r/20220802155152.1727594-14-robdclark@gmail.com
parent dd2f0d78

drivers/gpu/drm/msm/msm_gem_shrinker.c

+58 −12
Original line number Diff line number Diff line
@@ -24,6 +24,13 @@ static bool can_swap(void) 
	return enable_eviction && get_nr_swap_pages() > 0;

}



static bool can_block(struct shrink_control *sc)

{

	if (sc->gfp_mask & __GFP_ATOMIC)

		return false;

	return current_is_kswapd() || (sc->gfp_mask & __GFP_RECLAIM);

}



static unsigned long

msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)

{
@@ -65,26 +72,65 @@ evict(struct drm_gem_object *obj) 
	return true;

}



static bool

wait_for_idle(struct drm_gem_object *obj)

{

	enum dma_resv_usage usage = dma_resv_usage_rw(true);

	return dma_resv_wait_timeout(obj->resv, usage, false, 1000) > 0;

}



static bool

active_purge(struct drm_gem_object *obj)

{

	if (!wait_for_idle(obj))

		return false;



	return purge(obj);

}



static bool

active_evict(struct drm_gem_object *obj)

{

	if (!wait_for_idle(obj))

		return false;



	return evict(obj);

}



static unsigned long

msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)

{

	struct msm_drm_private *priv =

		container_of(shrinker, struct msm_drm_private, shrinker);

	struct {

		struct drm_gem_lru *lru;

		bool (*shrink)(struct drm_gem_object *obj);

		bool cond;

		unsigned long freed;

	} stages[] = {

		/* Stages of progressively more aggressive/expensive reclaim: */

		{ &priv->lru.dontneed, purge,        true },

		{ &priv->lru.willneed, evict,        can_swap() },

		{ &priv->lru.dontneed, active_purge, can_block(sc) },

		{ &priv->lru.willneed, active_evict, can_swap() && can_block(sc) },

	};

	long nr = sc->nr_to_scan;

	unsigned long freed, purged, evicted = 0;



	purged = drm_gem_lru_scan(&priv->lru.dontneed, nr, purge);

	nr -= purged;



	if (can_swap() && nr > 0) {

		evicted = drm_gem_lru_scan(&priv->lru.willneed, nr, evict);

		nr -= evicted;

	unsigned long freed = 0;



	for (unsigned i = 0; (nr > 0) && (i < ARRAY_SIZE(stages)); i++) {

		if (!stages[i].cond)

			continue;

		stages[i].freed =

			drm_gem_lru_scan(stages[i].lru, nr, stages[i].shrink);

		nr -= stages[i].freed;

		freed += stages[i].freed;

	}



	freed = purged + evicted;



	if (freed)

		trace_msm_gem_shrink(sc->nr_to_scan, purged, evicted);

	if (freed) {

		trace_msm_gem_shrink(sc->nr_to_scan, stages[0].freed,

				     stages[1].freed, stages[2].freed,

				     stages[3].freed);

	}



	return (freed > 0) ? freed : SHRINK_STOP;

}

drivers/gpu/drm/msm/msm_gpu_trace.h

+10 −6
Original line number Diff line number Diff line
@@ -116,22 +116,26 @@ TRACE_EVENT(msm_gmu_freq_change, 




TRACE_EVENT(msm_gem_shrink,

		TP_PROTO(u32 nr_to_scan, u32 purged, u32 evicted),

		TP_ARGS(nr_to_scan, purged, evicted),

		TP_PROTO(u32 nr_to_scan, u32 purged, u32 evicted,

			 u32 active_purged, u32 active_evicted),

		TP_ARGS(nr_to_scan, purged, evicted, active_purged, active_evicted),

		TP_STRUCT__entry(

			__field(u32, nr_to_scan)

			__field(u32, purged)

			__field(u32, evicted)

			__field(u32, active_purged)

			__field(u32, active_evicted)

			),

		TP_fast_assign(

			__entry->nr_to_scan = nr_to_scan;

			__entry->purged = purged;

			__entry->evicted = evicted;

			__entry->active_purged = active_purged;

			__entry->active_evicted = active_evicted;

			),

		TP_printk("nr_to_scan=%u pages, purged=%u pages, evicted=%u pages",

			  __entry->nr_to_scan,

			  __entry->purged,

			  __entry->evicted)

		TP_printk("nr_to_scan=%u pg, purged=%u pg, evicted=%u pg, active_purged=%u pg, active_evicted=%u pg",

			  __entry->nr_to_scan, __entry->purged, __entry->evicted,

			  __entry->active_purged, __entry->active_evicted)

);