D32250.id96186.diff
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

D32250.id96186.diff
View Options

	diff --git a/stand/common/bcache.c b/stand/common/bcache.c
	--- a/stand/common/bcache.c
	+++ b/stand/common/bcache.c
	@@ -67,6 +67,7 @@
	size_t bcache_nblks;
	size_t ra;
	daddr_t bcache_nextblkno;
	+ size_t ralen;
	};

	static u_int bcache_total_nblks; /* set by bcache_init */
	@@ -250,14 +251,23 @@
	* increase it when we notice that readahead was useful and decrease
	* it when we notice that readahead was not useful.
	*/
	- if (complete) {
	+ if (complete \|\| (i == bc->ralen && bc->ralen > 0)) {
	if (bc->ra < BCACHE_READAHEAD)
	bc->ra <<= 1; /* increase read ahead */
	} else {
	- if (nblk - i > BCACHE_MINREADAHEAD && bc->ra > BCACHE_MINREADAHEAD)
	+ if (nblk - i > BCACHE_MINREADAHEAD && bc->ralen > 0 &&
	+ bc->ra > BCACHE_MINREADAHEAD)
	bc->ra >>= 1; /* reduce read ahead */
	}

	+ /* Adjust our "unconsumed readahead" value. */
	+ if (blk == bc->bcache_nextblkno) {
	+ if (nblk > bc->ralen)
	+ bc->ralen = 0;
	+ else
	+ bc->ralen -= nblk;
	+ }
	+
	if (complete) { /* whole set was in cache, return it */
	bcopy(bc->bcache_data + (bcache_blksize * BHASH(bc, blk)), buf, size);
	goto done;
	@@ -314,7 +324,10 @@
	if (ra != 0 && ra != bc->bcache_nblks) { /* do we have RA space? */
	ra = MIN(bc->ra, ra - 1);
	ra = rounddown(ra, 16); /* multiple of 16 blocks */
	+ bc->ralen = ra;
	p_size += ra;
	+ } else {
	+ bc->ralen = 0;
	}

	/* invalidate bcache */