sbitmap: optimise sbitmap_deferred_clear() (b78beea0) · Commits · 戴 / test

lib/sbitmap.c

+12 −12

Original line number	Diff line number	Diff line
		@@ -12,32 +12,32 @@
		/*
		* See if we have deferred clears that we can batch move
		*/
		static inline bool sbitmap_deferred_clear(struct sbitmap *sb, int index)
		static inline bool sbitmap_deferred_clear(struct sbitmap_word *map)
		{
		unsigned long mask, val;
		bool ret = false;
		unsigned long flags;

		spin_lock_irqsave(&sb->map[index].swap_lock, flags);
		spin_lock_irqsave(&map->swap_lock, flags);

		if (!sb->map[index].cleared)
		if (!map->cleared)
		goto out_unlock;

		/*
		* First get a stable cleared mask, setting the old mask to 0.
		*/
		mask = xchg(&sb->map[index].cleared, 0);
		mask = xchg(&map->cleared, 0);

		/*
		* Now clear the masked bits in our free word
		*/
		do {
		val = sb->map[index].word;
		} while (cmpxchg(&sb->map[index].word, val, val & ~mask) != val);
		val = map->word;
		} while (cmpxchg(&map->word, val, val & ~mask) != val);

		ret = true;
		out_unlock:
		spin_unlock_irqrestore(&sb->map[index].swap_lock, flags);
		spin_unlock_irqrestore(&map->swap_lock, flags);
		return ret;
		}

		@@ -92,7 +92,7 @@ void sbitmap_resize(struct sbitmap *sb, unsigned int depth)
		unsigned int i;

		for (i = 0; i < sb->map_nr; i++)
		sbitmap_deferred_clear(sb, i);
		sbitmap_deferred_clear(&sb->map[i]);

		sb->depth = depth;
		sb->map_nr = DIV_ROUND_UP(sb->depth, bits_per_word);
		@@ -139,15 +139,15 @@ static int __sbitmap_get_word(unsigned long *word, unsigned long depth,
		static int sbitmap_find_bit_in_index(struct sbitmap *sb, int index,
		unsigned int alloc_hint, bool round_robin)
		{
		struct sbitmap_word *map = &sb->map[index];
		int nr;

		do {
		nr = __sbitmap_get_word(&sb->map[index].word,
		sb->map[index].depth, alloc_hint,
		nr = __sbitmap_get_word(&map->word, map->depth, alloc_hint,
		!round_robin);
		if (nr != -1)
		break;
		if (!sbitmap_deferred_clear(sb, index))
		if (!sbitmap_deferred_clear(map))
		break;
		} while (1);

		@@ -207,7 +207,7 @@ again:
		break;
		}

		if (sbitmap_deferred_clear(sb, index))
		if (sbitmap_deferred_clear(&sb->map[index]))
		goto again;

		/* Jump to next index. */

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