Hello tech@.
I just committed some significant fixes to the buffer cache in -current.
(you want to look for version 1.139 of vfs_bio.c)
If you have such a current kernel, you may wish to try the following
diff - it is a backout of a previous commit that emasculated softdep
in order to make is safe with our buffer cache at the time. With
version 1.139 of vfs_bio.c I believe this is no longer needed.
I have done extensive testing with the diff below and beating up
softdep filesystems - it both works, and, actually can provide
significantly increased performance in some situations.
You too may want to try what is below. If you do, please drop me a
note indicating what you were doing with it, and what you noticed,
sucesses, failures, performance changes, etc. I would like to know
about all.
WARNING - if you apply this to something without version 1.139 of
vfs_bio.c, you may hang your machine.
Thanks
-Bob
---------------8<----------------
Index: ufs/ffs/ffs_inode.c
===================================================================
RCS file: /cvs/src/sys/ufs/ffs/ffs_inode.c,v
retrieving revision 1.61
diff -u -p -r1.61 ffs_inode.c
--- ufs/ffs/ffs_inode.c 23 Mar 2012 15:51:26 -0000 1.61
+++ ufs/ffs/ffs_inode.c 20 Sep 2012 13:27:05 -0000
@@ -164,10 +164,8 @@ ffs_truncate(struct inode *oip, off_t le
struct buf *bp;
int offset, size, level;
long count, nblocks, vflags, blocksreleased = 0;
- int i, aflags, error, allerror, indirect = 0;
+ int i, aflags, error, allerror;
off_t osize;
- extern int num_indirdep;
- extern int max_indirdep;
if (length < 0)
return (EINVAL);
@@ -243,8 +241,6 @@ ffs_truncate(struct inode *oip, off_t le
cred, aflags, &bp);
if (error)
return (error);
- if (bp->b_lblkno >= NDADDR)
- indirect = 1;
DIP_ASSIGN(oip, size, length);
uvm_vnp_setsize(ovp, length);
(void) uvm_vnp_uncache(ovp);
@@ -253,20 +249,7 @@ ffs_truncate(struct inode *oip, off_t le
else
bawrite(bp);
oip->i_flag |= IN_CHANGE | IN_UPDATE;
- error = UFS_UPDATE(oip, MNT_WAIT);
- if (DOINGSOFTDEP(ovp) && num_indirdep > max_indirdep)
- if (indirect) {
- /*
- * If the number of pending indirect block
- * dependencies is sufficiently close to the
- * maximum number of simultaneously mappable
- * buffers force a sync on the vnode to prevent
- * buffer cache exhaustion.
- */
- VOP_FSYNC(ovp, curproc->p_ucred, MNT_WAIT,
- curproc);
- }
- return (error);
+ return (UFS_UPDATE(oip, MNT_WAIT));
}
uvm_vnp_setsize(ovp, length);
Index: ufs/ffs/ffs_softdep.c
===================================================================
RCS file: /cvs/src/sys/ufs/ffs/ffs_softdep.c,v
retrieving revision 1.112
diff -u -p -r1.112 ffs_softdep.c
--- ufs/ffs/ffs_softdep.c 18 Sep 2011 23:20:28 -0000 1.112
+++ ufs/ffs/ffs_softdep.c 20 Sep 2012 13:27:05 -0000
@@ -526,8 +526,6 @@ workitem_free(struct worklist *item)
STATIC struct workhead softdep_workitem_pending;
STATIC struct worklist *worklist_tail;
STATIC int num_on_worklist; /* number of worklist items to be processed */
-STATIC int num_indirdep; /* number of indirdep items to be processed */
-STATIC int max_indirdep; /* maximum number of indirdep items allowed */
STATIC int softdep_worklist_busy; /* 1 => trying to do unmount */
STATIC int softdep_worklist_req; /* serialized waiters */
STATIC int max_softdeps; /* maximum number of structs before slowdown */
@@ -1142,8 +1140,6 @@ top:
void
softdep_initialize(void)
{
- extern vsize_t bufkvm;
- max_indirdep = (int)bufkvm / MAXPHYS * 80 / 100;
bioops.io_start = softdep_disk_io_initiation;
bioops.io_complete = softdep_disk_write_complete;
@@ -1819,14 +1815,12 @@ setup_allocindir_phase2(struct buf *bp,
if (indirdep->ir_savebp != NULL)
brelse(newindirdep->ir_savebp);
WORKITEM_FREE(newindirdep, D_INDIRDEP);
- num_indirdep--;
}
if (indirdep)
break;
newindirdep = pool_get(&indirdep_pool, PR_WAITOK);
newindirdep->ir_list.wk_type = D_INDIRDEP;
newindirdep->ir_state = ATTACHED;
- num_indirdep++;
if (ip->i_ump->um_fstype == UM_UFS1)
newindirdep->ir_state |= UFS1FMT;
LIST_INIT(&newindirdep->ir_deplisthd);
@@ -2446,7 +2440,6 @@ indir_trunc(struct inode *ip, daddr64_t
}
WORKLIST_REMOVE(wk);
WORKITEM_FREE(indirdep, D_INDIRDEP);
- num_indirdep--;
if (LIST_FIRST(&bp->b_dep) != NULL) {
FREE_LOCK(&lk);
panic("indir_trunc: dangling dep");
@@ -3288,7 +3281,6 @@ softdep_disk_io_initiation(struct buf *b
wk->wk_state &= ~ONWORKLIST;
LIST_REMOVE(wk, wk_list);
WORKITEM_FREE(indirdep, D_INDIRDEP);
- num_indirdep--;
FREE_LOCK(&lk);
brelse(sbp);
ACQUIRE_LOCK(&lk);
Index: ufs/ffs/ffs_vnops.c
===================================================================
RCS file: /cvs/src/sys/ufs/ffs/ffs_vnops.c,v
retrieving revision 1.69
diff -u -p -r1.69 ffs_vnops.c
--- ufs/ffs/ffs_vnops.c 17 Sep 2012 14:22:23 -0000 1.69
+++ ufs/ffs/ffs_vnops.c 20 Sep 2012 13:37:00 -0000
@@ -295,12 +295,10 @@ ffs_write(void *v)
struct inode *ip;
struct fs *fs;
struct buf *bp;
- struct proc *p;
daddr64_t lbn;
off_t osize;
int blkoffset, error, extended, flags, ioflag, resid, size, xfersize;
int overrun;
- extern int num_indirdep, max_indirdep;
extended = 0;
ioflag = ap->a_ioflag;
@@ -367,11 +365,7 @@ ffs_write(void *v)
if (uio->uio_offset + xfersize > DIP(ip, size)) {
DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
uvm_vnp_setsize(vp, DIP(ip, size));
- /* Are we extending into an indirect block? */
- if (bp->b_lblkno < NDADDR)
- extended = 1;
- else
- extended = 2;
+ extended = 1;
}
(void)uvm_vnp_uncache(vp);
@@ -415,21 +409,8 @@ ffs_write(void *v)
uio->uio_offset -= resid - uio->uio_resid;
uio->uio_resid = resid;
}
- } else if (resid > uio->uio_resid) {
- if (ioflag & IO_SYNC)
- error = UFS_UPDATE(ip, MNT_WAIT);
- if (DOINGSOFTDEP(vp) && num_indirdep > max_indirdep)
- if (extended > 1) {
- /*
- * If the number of pending indirect block
- * dependencies is sufficiently close to the
- * maximum number of simultaneously mappable
- * buffers force a sync on the vnode to prevent
- * buffer cache exhaustion.
- */
- p = uio->uio_procp;
- VOP_FSYNC(vp, NULL, MNT_WAIT, p);
- }
+ } else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
+ error = UFS_UPDATE(ip, MNT_WAIT);
}
/* correct the result for writes clamped by vn_fsizechk() */
uio->uio_resid += overrun;
