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author | peter <peter@FreeBSD.org> | 2001-03-17 09:31:06 +0000 |
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committer | peter <peter@FreeBSD.org> | 2001-03-17 09:31:06 +0000 |
commit | 670e711dd19510316ecaa1f30d78f16ba66492f6 (patch) | |
tree | df728469695bfff83fcf93f9e9a460606a09b3f1 /sys/nfsclient/nfs_node.c | |
parent | 400aa0706c1d55d12d0405666ddac2d3e3ec5d69 (diff) | |
download | FreeBSD-src-670e711dd19510316ecaa1f30d78f16ba66492f6.zip FreeBSD-src-670e711dd19510316ecaa1f30d78f16ba66492f6.tar.gz |
Use a generic implementation of the Fowler/Noll/Vo hash (FNV hash).
Make the name cache hash as well as the nfsnode hash use it.
As a special tweak, create an unsigned version of register_t. This allows
us to use a special tweak for the 64 bit versions that significantly
speeds up the i386 version (ie: int64 XOR int64 is slower than int64
XOR int32).
The code layout is a little strange for the string function, but I was
able to get between 5 to 10% improvement over the original version I
started with. The layout affects gcc code generation choices and this way
was fastest on x86 and alpha.
Note that 'CPUTYPE=p3' etc makes a fair difference to this. It is
around 45% faster with -march=pentiumpro on a p6 cpu.
Diffstat (limited to 'sys/nfsclient/nfs_node.c')
-rw-r--r-- | sys/nfsclient/nfs_node.c | 30 |
1 files changed, 2 insertions, 28 deletions
diff --git a/sys/nfsclient/nfs_node.c b/sys/nfsclient/nfs_node.c index 365d7f2..450729d 100644 --- a/sys/nfsclient/nfs_node.c +++ b/sys/nfsclient/nfs_node.c @@ -44,6 +44,7 @@ #include <sys/namei.h> #include <sys/vnode.h> #include <sys/malloc.h> +#include <sys/fnv_hash.h> #include <vm/vm_zone.h> @@ -72,33 +73,6 @@ nfs_nhinit() } /* - * Compute an entry in the NFS hash table structure - * - * Hash based on: http://www.isthe.com/chongo/tech/comp/fnv/ - * by Glenn Fowler, Phong Vo and Landon Curt Noll - * aka the "Fowler / Noll / Vo Hash" (FNV) - */ -#define FNV_32_PRIME ((u_int32_t) 0x01000193UL) -#define FNV1_32_INIT ((u_int32_t) 33554467UL) -u_long -nfs_hash(fhp, fhsize) - nfsfh_t *fhp; - int fhsize; -{ - u_char *fhpp; - u_int32_t hval; - int i; - - fhpp = &fhp->fh_bytes[0]; - hval = FNV1_32_INIT; - for (i = 0; i < fhsize; i++) { - hval *= FNV_32_PRIME; - hval ^= (u_int32_t)*fhpp++; - } - return (hval); -} - -/* * Look up a vnode/nfsnode by file handle. * Callers must check for mount points!! * In all cases, a pointer to a @@ -133,7 +107,7 @@ nfs_nget(mntp, fhp, fhsize, npp) rsflags = 0; retry: - nhpp = NFSNOHASH(nfs_hash(fhp, fhsize)); + nhpp = NFSNOHASH(fnv32_hashbuf(fhp->fh_bytes, fhsize)); loop: for (np = nhpp->lh_first; np != 0; np = np->n_hash.le_next) { if (mntp != NFSTOV(np)->v_mount || np->n_fhsize != fhsize || |