lmkd: Use aggregate zone watermarks as low memory threshold am: 4787ab452f (b6563cbe) · Commits · e / os / android_system_core

lmkd/lmkd.c

+47 −25

Original line number	Diff line number	Diff line
		@@ -1951,41 +1951,49 @@ enum zone_watermark {
		WMARK_NONE
		};

		struct zone_watermarks {
		long high_wmark;
		long low_wmark;
		long min_wmark;
		};

		/*
		* Returns lowest breached watermark or WMARK_NONE.
		*/
		static enum zone_watermark get_lowest_watermark(struct zoneinfo *zi)
		static enum zone_watermark get_lowest_watermark(union meminfo *mi,
		struct zone_watermarks *watermarks)
		{
		enum zone_watermark wmark = WMARK_NONE;
		int64_t nr_free_pages = mi->field.nr_free_pages - mi->field.cma_free;

		if (nr_free_pages < watermarks->min_wmark) {
		return WMARK_MIN;
		}
		if (nr_free_pages < watermarks->low_wmark) {
		return WMARK_LOW;
		}
		if (nr_free_pages < watermarks->high_wmark) {
		return WMARK_HIGH;
		}
		return WMARK_NONE;
		}

		void calc_zone_watermarks(struct zoneinfo zi, struct zone_watermarks watermarks) {
		memset(watermarks, 0, sizeof(struct zone_watermarks));

		for (int node_idx = 0; node_idx < zi->node_count; node_idx++) {
		struct zoneinfo_node *node = &zi->nodes[node_idx];

		for (int zone_idx = 0; zone_idx < node->zone_count; zone_idx++) {
		struct zoneinfo_zone *zone = &node->zones[zone_idx];
		int zone_free_mem;

		if (!zone->fields.field.present) {
		continue;
		}

		zone_free_mem = zone->fields.field.nr_free_pages - zone->fields.field.nr_free_cma;
		if (zone_free_mem > zone->max_protection + zone->fields.field.high) {
		continue;
		watermarks->high_wmark += zone->max_protection + zone->fields.field.high;
		watermarks->low_wmark += zone->max_protection + zone->fields.field.low;
		watermarks->min_wmark += zone->max_protection + zone->fields.field.min;
		}
		if (zone_free_mem > zone->max_protection + zone->fields.field.low) {
		if (wmark > WMARK_HIGH) wmark = WMARK_HIGH;
		continue;
		}
		if (zone_free_mem > zone->max_protection + zone->fields.field.min) {
		if (wmark > WMARK_LOW) wmark = WMARK_LOW;
		continue;
		}
		wmark = WMARK_MIN;
		}
		}

		return wmark;
		}

		static void mp_event_psi(int data, uint32_t events, struct polling_params *poll_params) {
		@@ -2012,10 +2020,11 @@ static void mp_event_psi(int data, uint32_t events, struct polling_params *poll_
		static bool killing;
		static int thrashing_limit;
		static bool in_reclaim;
		static struct zone_watermarks watermarks;
		static struct timespec wmark_update_tm;

		union meminfo mi;
		union vmstat vs;
		struct zoneinfo zi;
		struct timespec curr_tm;
		int64_t thrashing = 0;
		bool swap_is_low = false;
		@@ -2088,12 +2097,25 @@ static void mp_event_psi(int data, uint32_t events, struct polling_params *poll_
		}
		in_reclaim = true;

		/* Find out which watermark is breached if any */
		/*
		* Refresh watermarks once per min in case user updated one of the margins.
		* TODO: b/140521024 replace this periodic update with an API for AMS to notify LMKD
		* that zone watermarks were changed by the system software.
		*/
		if (watermarks.high_wmark == 0 \|\| get_time_diff_ms(&wmark_update_tm, &curr_tm) > 60000) {
		struct zoneinfo zi;

		if (zoneinfo_parse(&zi) < 0) {
		ALOGE("Failed to parse zoneinfo!");
		return;
		}
		wmark = get_lowest_watermark(&zi);

		calc_zone_watermarks(&zi, &watermarks);
		wmark_update_tm = curr_tm;
		}

		/* Find out which watermark is breached if any */
		wmark = get_lowest_watermark(&mi, &watermarks);

		/*
		* TODO: move this logic into a separate function