diff options
author | mjg <mjg@FreeBSD.org> | 2017-01-24 19:45:33 +0000 |
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committer | mjg <mjg@FreeBSD.org> | 2017-01-24 19:45:33 +0000 |
commit | 22001f91a93303a76ee4e4458d750a898bfe4836 (patch) | |
tree | 96755caffc828fa70bd30f9a7e57107399ac1d37 | |
parent | b809b50b2fe2482b6f5b035699874ceb8ca6836a (diff) | |
download | FreeBSD-src-22001f91a93303a76ee4e4458d750a898bfe4836.zip FreeBSD-src-22001f91a93303a76ee4e4458d750a898bfe4836.tar.gz |
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
-rw-r--r-- | sys/kern/vfs_cache.c | 55 |
1 files changed, 27 insertions, 28 deletions
diff --git a/sys/kern/vfs_cache.c b/sys/kern/vfs_cache.c index 45aa053..02b8e2b 100644 --- a/sys/kern/vfs_cache.c +++ b/sys/kern/vfs_cache.c @@ -229,8 +229,6 @@ SYSCTL_UINT(_vfs, OID_AUTO, ncneghitsrequeue, CTLFLAG_RW, &ncneghitsrequeue, 0, 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 vnode **vpp, struct componentname *cnp, 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 celockstate *cel, struct vnode *vp) 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, struct vnode *vp, struct componentname *cnp, 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 *buf, enum uio_seg bufseg, u_int buflen, 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 vnode *vn, char **retbuf, char **freebuf) 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, struct vnode *vn, 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, struct vnode *vp, char *path, 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. */ |