summaryrefslogtreecommitdiffstats
path: root/tools/diag/dumpvfscache/dumpvfscache.c
blob: 3f5eb5793a8a0fd453d5f8b196ab5134c45e5448 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/* $FreeBSD$ */
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <kvm.h>
#include <nlist.h>
#include <sysexits.h>
#include <sys/uio.h>
#include <sys/namei.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/time.h>
#include <sys/vnode.h>
/*----------------------------------*/
static u_int crc16_table[16] = { 
    0x0000, 0xCC01, 0xD801, 0x1400,
    0xF001, 0x3C00, 0x2800, 0xE401,
    0xA001, 0x6C00, 0x7800, 0xB401,
    0x5000, 0x9C01, 0x8801, 0x4400 
};

/* XXX Taken from sys/kern/vfs_cache.c */
struct	namecache {
	LIST_ENTRY(namecache) nc_hash;
	LIST_ENTRY(namecache) nc_src;
	TAILQ_ENTRY(namecache) nc_dst;
	struct	vnode *nc_dvp;
	struct	vnode *nc_vp;
	u_char	nc_flag;
	u_char	nc_nlen;
	char	nc_name[0];
};

static u_short
wlpsacrc(u_char *buf, u_int len)
{
    u_short     crc = 0;
    int         i, r1;
    
    for (i = 0; i < len; i++, buf++) {
        /* lower 4 bits */
        r1 = crc16_table[crc & 0xF];
        crc = (crc >> 4) & 0x0FFF;
        crc = crc ^ r1 ^ crc16_table[*buf & 0xF];
        
        /* upper 4 bits */
        r1 = crc16_table[crc & 0xF];
        crc = (crc >> 4) & 0x0FFF;
        crc = crc ^ r1 ^ crc16_table[(*buf >> 4) & 0xF];
    }
    return(crc);
}

/*----------------------------------*/
struct nlist nl[] = {
	{ "_nchash", 0},
	{ "_nchashtbl", 0},
	{ 0, 0 },
};

int histo[2047];
int histn[2047];
int *newbucket;

int
main(int argc, char **argv)
{
	int nchash, i, j, k, kn;
	int nb, p1, p2;
	u_long p;
	LIST_HEAD(nchashhead, namecache) *nchashtbl;
	struct namecache *nc;
	struct vnode vn;

	kvm_t *kvm = kvm_open(NULL, NULL, NULL, O_RDONLY, argv[0]);
	if (kvm == NULL)
		return(EX_OSERR);

	printf("kvm: %p\n", kvm);
	printf("kvm_nlist: %d\n", kvm_nlist(kvm, nl));
	kvm_read(kvm, nl[0].n_value, &nchash, sizeof nchash);
	nchash++;
	nchashtbl = malloc(nchash * sizeof *nchashtbl);
	nc = malloc(sizeof *nc + NAME_MAX);
	newbucket = malloc(nchash * sizeof (int));
	memset(newbucket, 0, nchash * sizeof (int));
	kvm_read(kvm, nl[1].n_value, &p, sizeof p);
	kvm_read(kvm, p, nchashtbl, nchash * sizeof *nchashtbl);
	for (i=0; i < nchash; i++) {
#if 0
		printf("%d\n", i);
#endif
		nb=0;
		p = (u_long)LIST_FIRST(nchashtbl+i);
		while (p) {
			nb++;
			kvm_read(kvm, p, nc, sizeof *nc + NAME_MAX);
			kvm_read(kvm, (u_long)nc->nc_dvp, &vn, sizeof vn);
			nc->nc_name[nc->nc_nlen] = '\0';
			for (j=k=kn=0;nc->nc_name[j];j++) {
				k+= nc->nc_name[j];
				kn <<= 1;
				kn+= nc->nc_name[j];
			}
			/*
			kn = k;
			*/
			kn = wlpsacrc(nc->nc_name,nc->nc_nlen);

			/* kn += (u_long)vn.v_data >> 8;  */
			/* kn += (u_long)nc->nc_dvp >> 7;    */
			kn += vn.v_id; 
			kn &= (nchash - 1);
			newbucket[kn]++;
#if 1
			printf("%4d  dvp %08x  hash %08x  vp %08x  id %08x  name <%s>\n",
				i,nc->nc_dvp, k, nc->nc_vp, vn.v_id, nc->nc_name);
#endif
			p = (u_long)LIST_NEXT(nc, nc_hash);
		}
		histo[nb]++;
	}
	for (i=0; i < nchash; i++) {
		histn[newbucket[i]]++;
	}
	p1=p2 = 0;
	for (i=0;i<30;i++) {
		p1 += histo[i] * i;
		p2 += histn[i] * i;
		if (histo[i] || histn[i])
			printf("H%02d %4d %4d / %4d %4d\n",i,histo[i], p1 , histn[i], p2);
	}
		
	return (0);
}

OpenPOWER on IntegriCloud