diff options
Diffstat (limited to 'sys/kern/vfs_cluster.c')
| -rw-r--r-- | sys/kern/vfs_cluster.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/sys/kern/vfs_cluster.c b/sys/kern/vfs_cluster.c index ff1176ab1048..2c941fbec30a 100644 --- a/sys/kern/vfs_cluster.c +++ b/sys/kern/vfs_cluster.c @@ -57,7 +57,8 @@ #if defined(CLUSTERDEBUG) #include <sys/sysctl.h> static int rcluster= 0; -SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, ""); +SYSCTL_INT(_debug, OID_AUTO, rcluster, CTLFLAG_RW, &rcluster, 0, + "Debug VFS clustering code"); #endif static MALLOC_DEFINE(M_SEGMENT, "cluster_save buffer", "cluster_save buffer"); @@ -69,10 +70,16 @@ static struct buf * daddr_t blkno, long size, int run, struct buf *fbp)); static int write_behind = 1; -SYSCTL_INT(_vfs, OID_AUTO, write_behind, CTLFLAG_RW, &write_behind, 0, ""); +SYSCTL_INT(_vfs, OID_AUTO, write_behind, CTLFLAG_RW, &write_behind, 0, + "Cluster write-behind; 0: disable, 1: enable, 2: backed off"); +/* Page expended to mark partially backed buffers */ extern vm_page_t bogus_page; +/* + * Number of physical bufs (pbufs) this subsystem is allowed. + * Manipulated by vm_pager.c + */ extern int cluster_pbuf_freecnt; /* @@ -81,7 +88,8 @@ extern int cluster_pbuf_freecnt; #define MAXRA 32 /* - * This replaces bread. + * Read data to a buf, including read-ahead if we find this to be beneficial. + * cluster_read replaces bread. */ int cluster_read(vp, filesize, lblkno, size, cred, totread, seqcount, bpp) |