D31623.diff
No OneTemporary
Actions

Size

1 KB

Referenced Files

None

Subscribers

None

D31623.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
	@@ -66,6 +66,7 @@
	caddr_t bcache_data;
	size_t bcache_nblks;
	size_t ra;
	+ daddr_t bcache_nextblkno;
	};

	static u_int bcache_total_nblks; /* set by bcache_init */
	@@ -163,6 +164,7 @@
	}
	bcache_units++;
	bc->ra = BCACHE_READAHEAD; /* optimistic read ahead */
	+ bc->bcache_nextblkno = -1;
	return (bc);
	}

	@@ -291,6 +293,14 @@
	else
	ra = bc->bcache_nblks - BHASH(bc, p_blk + p_size);

	+ /*
	+ * Only trigger read-ahead if we detect two blocks being read
	+ * sequentially.
	+ */
	+ if ((bc->bcache_nextblkno != blk) && ra != 0) {
	+ ra = 0;
	+ }
	+
	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 */
	@@ -342,8 +352,11 @@
	}

	done:
	- if ((result == 0) && (rsize != NULL))
	- *rsize = size;
	+ if (result == 0) {
	+ if (rsize != NULL)
	+ *rsize = size;
	+ bc->bcache_nextblkno = blk + (size / DEV_BSIZE);
	+ }
	return(result);
	}