Author: mjg
Date: Tue Jan 24 19:45:33 2017
New Revision: 312718
URL: https://svnweb.freebsd.org/changeset/base/312718
Log:
MFC r310766,r310767,r310774,r310779:
cache: drop the NULL check from VP2VNODELOCK
Now that negative entries are annotated with a dedicated flag, NULL vnodes
are no longer passed.
==
cache: depessimize hashing macros/inlines
All hash sizes are power-of-2, but the compiler does not know that for
sure
and 'foo % size' forces doing a division.
Store the size - 1 and use 'foo & hash' instead which allows mere shift.
==
cache: move shrink lock init to nchinit
This gets rid of unnecesary sysinit usage.
While here also rename the lock to be consistent with the rest.
==
cache: sprinkle __predict_false
Modified:
stable/11/sys/kern/vfs_cache.c
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/sys/kern/vfs_cache.c
==============================================================================
--- stable/11/sys/kern/vfs_cache.c Tue Jan 24 19:42:24 2017
(r312717)
+++ stable/11/sys/kern/vfs_cache.c Tue Jan 24 19:45:33 2017
(r312718)
@@ -229,8 +229,6 @@ SYSCTL_UINT(_vfs, OID_AUTO, ncneghitsreq
struct nchstats nchstats; /* cache effectiveness
statistics */
static struct mtx ncneg_shrink_lock;
-MTX_SYSINIT(vfscache_shrink_neg, &ncneg_shrink_lock, "Name Cache shrink neg",
- MTX_DEF);
struct neglist {
struct mtx nl_lock;
@@ -242,30 +240,29 @@ static struct neglist ncneg_hot;
static int shrink_list_turn;
-static u_int numneglists;
+#define numneglists (ncneghash + 1)
+static u_int ncneghash;
static inline struct neglist *
NCP2NEGLIST(struct namecache *ncp)
{
- return (&neglists[(((uintptr_t)(ncp) >> 8) % numneglists)]);
+ return (&neglists[(((uintptr_t)(ncp) >> 8) & ncneghash)]);
}
-static u_int numbucketlocks;
+#define numbucketlocks (ncbuckethash + 1)
+static u_int ncbuckethash;
static struct rwlock_padalign *bucketlocks;
#define HASH2BUCKETLOCK(hash) \
- ((struct rwlock *)(&bucketlocks[((hash) % numbucketlocks)]))
+ ((struct rwlock *)(&bucketlocks[((hash) & ncbuckethash)]))
-static u_int numvnodelocks;
+#define numvnodelocks (ncvnodehash + 1)
+static u_int ncvnodehash;
static struct mtx *vnodelocks;
static inline struct mtx *
VP2VNODELOCK(struct vnode *vp)
{
- struct mtx *vlp;
- if (vp == NULL)
- return (NULL);
- vlp = &vnodelocks[(((uintptr_t)(vp) >> 8) % numvnodelocks)];
- return (vlp);
+ return (&vnodelocks[(((uintptr_t)(vp) >> 8) & ncvnodehash)]);
}
/*
@@ -1107,7 +1104,7 @@ cache_lookup(struct vnode *dvp, struct v
uint32_t hash;
int error, ltype;
- if (!doingcache) {
+ if (__predict_false(!doingcache)) {
cnp->cn_flags &= ~MAKEENTRY;
return (0);
}
@@ -1374,8 +1371,8 @@ cache_lock_vnodes_cel_3(struct celocksta
cache_assert_vlp_locked(cel->vlp[1]);
MPASS(cel->vlp[2] == NULL);
+ MPASS(vp != NULL);
vlp = VP2VNODELOCK(vp);
- MPASS(vlp != NULL);
ret = true;
if (vlp >= cel->vlp[1]) {
@@ -1547,13 +1544,13 @@ cache_enter_time(struct vnode *dvp, stru
VNASSERT(dvp == NULL || (dvp->v_iflag & VI_DOOMED) == 0, dvp,
("cache_enter: Doomed vnode used as src"));
- if (!doingcache)
+ if (__predict_false(!doingcache))
return;
/*
* Avoid blowout in namecache entries.
*/
- if (numcache >= desiredvnodes * ncsizefactor)
+ if (__predict_false(numcache >= desiredvnodes * ncsizefactor))
return;
cache_celockstate_init(&cel);
@@ -1779,21 +1776,21 @@ nchinit(void *dummy __unused)
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_ZINIT);
nchashtbl = hashinit(desiredvnodes * 2, M_VFSCACHE, &nchash);
- numbucketlocks = cache_roundup_2(mp_ncpus * 64);
- if (numbucketlocks > nchash + 1)
- numbucketlocks = nchash + 1;
+ ncbuckethash = cache_roundup_2(mp_ncpus * 64) - 1;
+ if (ncbuckethash > nchash)
+ ncbuckethash = nchash;
bucketlocks = malloc(sizeof(*bucketlocks) * numbucketlocks, M_VFSCACHE,
M_WAITOK | M_ZERO);
for (i = 0; i < numbucketlocks; i++)
rw_init_flags(&bucketlocks[i], "ncbuc", RW_DUPOK | RW_RECURSE);
- numvnodelocks = cache_roundup_2(mp_ncpus * 64);
+ ncvnodehash = cache_roundup_2(mp_ncpus * 64) - 1;
vnodelocks = malloc(sizeof(*vnodelocks) * numvnodelocks, M_VFSCACHE,
M_WAITOK | M_ZERO);
for (i = 0; i < numvnodelocks; i++)
mtx_init(&vnodelocks[i], "ncvn", NULL, MTX_DUPOK | MTX_RECURSE);
ncpurgeminvnodes = numbucketlocks;
- numneglists = 4;
+ ncneghash = 3;
neglists = malloc(sizeof(*neglists) * numneglists, M_VFSCACHE,
M_WAITOK | M_ZERO);
for (i = 0; i < numneglists; i++) {
@@ -1803,6 +1800,8 @@ nchinit(void *dummy __unused)
mtx_init(&ncneg_hot.nl_lock, "ncneglh", NULL, MTX_DEF);
TAILQ_INIT(&ncneg_hot.nl_list);
+ mtx_init(&ncneg_shrink_lock, "ncnegs", NULL, MTX_DEF);
+
numcalls = counter_u64_alloc(M_WAITOK);
dothits = counter_u64_alloc(M_WAITOK);
dotdothits = counter_u64_alloc(M_WAITOK);
@@ -2055,9 +2054,9 @@ kern___getcwd(struct thread *td, char *b
struct vnode *cdir, *rdir;
int error;
- if (disablecwd)
+ if (__predict_false(disablecwd))
return (ENODEV);
- if (buflen < 2)
+ if (__predict_false(buflen < 2))
return (EINVAL);
if (buflen > path_max)
buflen = path_max;
@@ -2108,9 +2107,9 @@ vn_fullpath(struct thread *td, struct vn
struct vnode *rdir;
int error;
- if (disablefullpath)
+ if (__predict_false(disablefullpath))
return (ENODEV);
- if (vn == NULL)
+ if (__predict_false(vn == NULL))
return (EINVAL);
buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
@@ -2142,9 +2141,9 @@ vn_fullpath_global(struct thread *td, st
char *buf;
int error;
- if (disablefullpath)
+ if (__predict_false(disablefullpath))
return (ENODEV);
- if (vn == NULL)
+ if (__predict_false(vn == NULL))
return (EINVAL);
buf = malloc(MAXPATHLEN, M_TEMP, M_WAITOK);
error = vn_fullpath1(td, vn, rootvnode, buf, retbuf, MAXPATHLEN);
@@ -2408,7 +2407,7 @@ vn_path_to_global_path(struct thread *td
ASSERT_VOP_ELOCKED(vp, __func__);
/* Return ENODEV if sysctl debug.disablefullpath==1 */
- if (disablefullpath)
+ if (__predict_false(disablefullpath))
return (ENODEV);
/* Construct global filesystem path from vp. */
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