Merge "mm: correct ALLOC_WMARK_MIN flag check for atomic allocations" (e814c38d) · Commits · e / devices / android_kernel_fairphone_FP5

mm/page_alloc.c

+42 −1

Original line number	Diff line number	Diff line
		@@ -2373,11 +2373,38 @@ static bool can_steal_fallback(unsigned int order, int start_mt)
		return false;
		}

		static bool boost_eligible(struct zone *z)
		{
		unsigned long high_wmark, threshold;
		unsigned long reclaim_eligible, free_pages;

		high_wmark = z->_watermark[WMARK_HIGH];
		reclaim_eligible = zone_page_state_snapshot(z, NR_ZONE_INACTIVE_FILE) +
		zone_page_state_snapshot(z, NR_ZONE_ACTIVE_FILE);
		free_pages = zone_page_state(z, NR_FREE_PAGES) -
		zone_page_state(z, NR_FREE_CMA_PAGES);
		threshold = high_wmark + (2 * mult_frac(high_wmark,
		watermark_boost_factor, 10000));

		/*
		* Don't boost watermark If we are already low on memory where the
		* boosting can simply put the watermarks at higher levels for a
		* longer duration of time and thus the other users relied on the
		* watermarks are forced to choose unintended decissions. If memory
		* is so low, kswapd in normal mode should help.
		*/

		if (reclaim_eligible < threshold && free_pages < threshold)
		return false;

		return true;
		}

		static inline void boost_watermark(struct zone *zone)
		{
		unsigned long max_boost;

		if (!watermark_boost_factor)
		if (!watermark_boost_factor \|\| !boost_eligible(zone))
		return;

		max_boost = mult_frac(zone->_watermark[WMARK_HIGH],
		@@ -3744,6 +3771,20 @@ get_page_from_freelist(gfp_t gfp_mask, unsigned int order, int alloc_flags,
		}

		mark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
		/*
		* Allow high, atomic, harder order-0 allocation requests
		* to skip the ->watermark_boost for min watermark check.
		* In doing so, check for:
		* 1) ALLOC_WMARK_MIN - Allow to wake up kswapd in the
		* slow path.
		* 2) ALLOC_HIGH - Allow high priority requests.
		* 3) ALLOC_HARDER - Allow (__GFP_ATOMIC && !__GFP_NOMEMALLOC),
		* of the others.
		*/
		if (unlikely(!order && !(alloc_flags & ALLOC_WMARK_MASK) &&
		(alloc_flags & (ALLOC_HARDER \| ALLOC_HIGH)))) {
		mark = zone->_watermark[WMARK_MIN];
		}
		if (!zone_watermark_fast(zone, order, mark,
		ac_classzone_idx(ac), alloc_flags)) {
		int ret;