Merge "mm: vmpressure: make vmpressure window variable" (ba83cd69) · Commits · e / devices / android_kernel_oneplus_sm8150

mm/vmpressure.c

+38 −3

Original line number	Diff line number	Diff line
		@@ -41,7 +41,7 @@
		* TODO: Make the window size depend on machine size, as we do for vmstat
		* thresholds. Currently we set it to 512 pages (2MB for 4KB pages).
		*/
		static const unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16;
		static unsigned long vmpressure_win = SWAP_CLUSTER_MAX * 16;

		/*
		* These thresholds are used when we account memory pressure through
		@@ -56,6 +56,11 @@ static unsigned long vmpressure_scale_max = 100;
		module_param_named(vmpressure_scale_max, vmpressure_scale_max,
		ulong, 0644);

		/* vmpressure values >= this will be scaled based on allocstalls */
		static unsigned long allocstall_threshold = 70;
		module_param_named(allocstall_threshold, allocstall_threshold,
		ulong, 0644);

		static struct vmpressure global_vmpressure;
		static BLOCKING_NOTIFIER_HEAD(vmpressure_notifier);

		@@ -186,8 +191,12 @@ static unsigned long vmpressure_calc_pressure(unsigned long scanned,
		static unsigned long vmpressure_account_stall(unsigned long pressure,
		unsigned long stall, unsigned long scanned)
		{
		unsigned long scale =
		((vmpressure_scale_max - pressure) * stall) / scanned;
		unsigned long scale;

		if (pressure < allocstall_threshold)
		return pressure;

		scale = ((vmpressure_scale_max - pressure) * stall) / scanned;

		return pressure + scale;
		}
		@@ -343,6 +352,29 @@ static void vmpressure_memcg(gfp_t gfp, struct mem_cgroup *memcg, bool tree,
		}
		#endif

		static void calculate_vmpressure_win(void)
		{
		long x;

		x = global_node_page_state(NR_FILE_PAGES) -
		global_node_page_state(NR_SHMEM) -
		total_swapcache_pages() +
		global_zone_page_state(NR_FREE_PAGES);
		if (x < 1)
		x = 1;
		/*
		* For low (free + cached), vmpressure window should be
		* small, and high for higher values of (free + cached).
		* But it should not be linear as well. This ensures
		* timely vmpressure notifications when system is under
		* memory pressure, and optimal number of events when
		* cached is high. The sqaure root function is empirically
		* found to serve the purpose.
		*/
		x = int_sqrt(x);
		vmpressure_win = x;
		}

		static void vmpressure_global(gfp_t gfp, unsigned long scanned,
		unsigned long reclaimed)
		{
		@@ -357,6 +389,9 @@ static void vmpressure_global(gfp_t gfp, unsigned long scanned,
		return;

		spin_lock(&vmpr->sr_lock);
		if (!vmpr->scanned)
		calculate_vmpressure_win();

		vmpr->scanned += scanned;
		vmpr->reclaimed += reclaimed;