procps/proc/slab.c
Takayuki Nagata 99d71ad581 bprocps: fix order of operations for %use of slabinfo
In some environments, 100 * nr_active_objs is calculated at first,
and lower 32bit of the result is divided by nr_objs.
If 100 * nr_active_objs > 42949672, %use will be incorrect.

Signed-off-by: Takayuki Nagata <tnagata@redhat.com>
2016-04-25 20:20:08 +10:00

355 lines
9.6 KiB
C

/*
* slab.c - slab related functions for libproc
*
* Chris Rivera <cmrivera@ufl.edu>
* Robert Love <rml@tech9.net>
*
* Copyright (C) 2003 Chris Rivera
* Copyright 2004, Albert Cahalan
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <limits.h>
#include <ctype.h>
#include "slab.h"
#include "procps.h"
#include "alloc.h"
#define SLABINFO_LINE_LEN 2048
#define SLABINFO_VER_LEN 100
#define SLABINFO_FILE "/proc/slabinfo"
static struct slab_info *free_index;
/*
* get_slabnode - allocate slab_info structures using a free list
*
* In the fast path, we simply return a node off the free list. In the slow
* list, we malloc() a new node. The free list is never automatically reaped,
* both for simplicity and because the number of slab caches is fairly
* constant.
*/
static struct slab_info *get_slabnode(void)
{
struct slab_info *node;
if (free_index) {
node = free_index;
free_index = free_index->next;
} else {
node = xmalloc(sizeof(struct slab_info));
}
return node;
}
/*
* slab_badname_detect - return true if current slab was declared with
* whitespaces for instance
* FIXME :Other cases ?
*/
static int slab_badname_detect(const char *restrict buffer)
{
int numberarea=0;
while (*buffer){
if((*buffer)==' ')
numberarea=1;
if(isalpha(*buffer)&&numberarea)
return 1;
buffer++;
}
return 0;
}
/*
* put_slabinfo - return all allocated nodes to the free list
*/
void put_slabinfo(struct slab_info *head)
{
free_index = head;
}
/*
* free_slabinfo - deallocate the memory associated with each node in the
* slab_info linked list
*/
void free_slabinfo(struct slab_info *list)
{
while (list) {
struct slab_info *temp = list->next;
free(list);
list = temp;
}
}
/* parse_slabinfo20 - actual parse routine for slabinfo 2.x (2.6 kernels)
* Note: difference between 2.0 and 2.1 is in the ": globalstat" part where version 2.1
* has extra column <nodeallocs>. We don't use ": globalstat" part in both versions.
*
* Formats (we don't use "statistics" extensions)
*
* slabinfo - version: 2.1
* # name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
* : tunables <batchcount> <limit> <sharedfactor> \
* : slabdata <active_slabs> <num_slabs> <sharedavail>
*
* slabinfo - version: 2.1 (statistics)
* # name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
* : tunables <batchcount> <limit> <sharedfactor> \
* : slabdata <active_slabs> <num_slabs> <sharedavail> \
* : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <freelimit> <nodeallocs> \
* : cpustat <allochit> <allocmiss> <freehit> <freemiss>
*
* slabinfo - version: 2.0
* # name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
* : tunables <batchcount> <limit> <sharedfactor> \
* : slabdata <active_slabs> <num_slabs> <sharedavail>
*
* slabinfo - version: 2.0 (statistics)
* # name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> \
* : tunables <batchcount> <limit> <sharedfactor> \
* : slabdata <active_slabs> <num_slabs> <sharedavail> \
* : globalstat <listallocs> <maxobjs> <grown> <reaped> <error> <maxfreeable> <freelimit> \
* : cpustat <allochit> <allocmiss> <freehit> <freemiss>
*/
static int parse_slabinfo20(struct slab_info **list, struct slab_stat *stats,
FILE *f)
{
struct slab_info *curr = NULL, *prev = NULL;
char buffer[SLABINFO_LINE_LEN];
int entries = 0;
int page_size = getpagesize();
stats->min_obj_size = INT_MAX;
stats->max_obj_size = 0;
while (fgets(buffer, SLABINFO_LINE_LEN, f)) {
int assigned;
if (buffer[0] == '#')
continue;
curr = get_slabnode();
if (!curr)
break;
if (entries++ == 0)
*list = curr;
else
if (prev)
prev->next = curr;
assigned = sscanf(buffer, "%" STRINGIFY(SLAB_INFO_NAME_LEN)
"s %d %d %d %d %d : tunables %*d %*d %*d : \
slabdata %d %d %*d", curr->name,
&curr->nr_active_objs, &curr->nr_objs,
&curr->obj_size, &curr->objs_per_slab,
&curr->pages_per_slab, &curr->nr_active_slabs,
&curr->nr_slabs);
if (assigned < 8) {
fprintf(stderr, "unrecognizable data in slabinfo!\n");
curr = NULL;
break;
}
if (curr->obj_size < stats->min_obj_size)
stats->min_obj_size = curr->obj_size;
if (curr->obj_size > stats->max_obj_size)
stats->max_obj_size = curr->obj_size;
curr->cache_size = (unsigned long)curr->nr_slabs * curr->pages_per_slab * page_size;
if (curr->nr_objs) {
curr->use = 100 * (curr->nr_active_objs / curr->nr_objs);
stats->nr_active_caches++;
} else
curr->use = 0;
stats->nr_objs += curr->nr_objs;
stats->nr_active_objs += curr->nr_active_objs;
stats->total_size += (unsigned long)curr->nr_objs * curr->obj_size;
stats->active_size += (unsigned long)curr->nr_active_objs * curr->obj_size;
stats->nr_pages += curr->nr_slabs * curr->pages_per_slab;
stats->nr_slabs += curr->nr_slabs;
stats->nr_active_slabs += curr->nr_active_slabs;
prev = curr;
}
if (!curr) {
fprintf(stderr, "\rerror reading slabinfo!\n");
return 1;
}
curr->next = NULL;
stats->nr_caches = entries;
if (stats->nr_objs)
stats->avg_obj_size = stats->total_size / stats->nr_objs;
return 0;
}
/*
* parse_slabinfo11 - actual parsing routine for slabinfo 1.1 (2.4 kernels)
*/
static int parse_slabinfo11(struct slab_info **list, struct slab_stat *stats,
FILE *f)
{
struct slab_info *curr = NULL, *prev = NULL;
char buffer[SLABINFO_LINE_LEN];
int entries = 0;
int page_size = getpagesize();
stats->min_obj_size = INT_MAX;
stats->max_obj_size = 0;
while (fgets(buffer, SLABINFO_LINE_LEN, f)) {
int assigned;
curr = get_slabnode();
if (!curr)
break;
if (entries++ == 0)
*list = curr;
else
if (prev)
prev->next = curr;
assigned = sscanf(buffer, "%" STRINGIFY(SLAB_INFO_NAME_LEN)
"s %d %d %d %d %d %d",
curr->name, &curr->nr_active_objs,
&curr->nr_objs, &curr->obj_size,
&curr->nr_active_slabs, &curr->nr_slabs,
&curr->pages_per_slab);
if (assigned < 6) {
fprintf(stderr, "unrecognizable data in your slabinfo version 1.1\n\r");
if(slab_badname_detect(buffer))
fprintf(stderr, "Found an error in cache name at line %s\n", buffer);
curr = NULL;
break;
}
if (curr->obj_size < stats->min_obj_size)
stats->min_obj_size = curr->obj_size;
if (curr->obj_size > stats->max_obj_size)
stats->max_obj_size = curr->obj_size;
curr->cache_size = (unsigned long)curr->nr_slabs * curr->pages_per_slab * page_size;
if (curr->nr_objs) {
curr->use = 100 * curr->nr_active_objs / curr->nr_objs;
stats->nr_active_caches++;
} else
curr->use = 0;
if (curr->obj_size)
curr->objs_per_slab = curr->pages_per_slab *
page_size / curr->obj_size;
stats->nr_objs += curr->nr_objs;
stats->nr_active_objs += curr->nr_active_objs;
stats->total_size += (unsigned long)curr->nr_objs * curr->obj_size;
stats->active_size += (unsigned long)curr->nr_active_objs * curr->obj_size;
stats->nr_pages += curr->nr_slabs * curr->pages_per_slab;
stats->nr_slabs += curr->nr_slabs;
stats->nr_active_slabs += curr->nr_active_slabs;
prev = curr;
}
if (!curr) {
fprintf(stderr, "\rerror reading slabinfo!\n");
return 1;
}
curr->next = NULL;
stats->nr_caches = entries;
if (stats->nr_objs)
stats->avg_obj_size = stats->total_size / stats->nr_objs;
return 0;
}
/*
* parse_slabinfo10 - actual parsing routine for slabinfo 1.0 (2.2 kernels)
*
* Not yet implemented. Please feel free.
*/
static int parse_slabinfo10(struct slab_info **list, struct slab_stat *stats,
FILE *f)
{
(void) list, (void) stats, (void) f;
fprintf(stderr, "slabinfo version 1.0 not yet supported\n");
return 1;
}
/*
* slabinfo - parse the system's slabinfo and fill out both a linked list of
* slab_info structures and the slab_stat structure
*
* The function returns zero on success, in which case 'list' and 'stats' are
* valid. Nonzero is returned on failure and the state of 'list' and 'stats'
* are undefined.
*/
int get_slabinfo(struct slab_info **list, struct slab_stat *stats)
{
FILE *slabfile;
char buffer[SLABINFO_VER_LEN];
int major, minor, ret = 0;
slabfile = fopen(SLABINFO_FILE, "r");
if (!slabfile) {
perror("fopen " SLABINFO_FILE);
return 1;
}
if (!fgets(buffer, SLABINFO_VER_LEN, slabfile)) {
fprintf(stderr, "cannot read from slabinfo\n");
fclose(slabfile);
return 1;
}
if (sscanf(buffer, "slabinfo - version: %d.%d", &major, &minor) != 2) {
fprintf(stderr, "not the good old slabinfo we know\n");
fclose(slabfile);
return 1;
}
if (major == 2)
ret = parse_slabinfo20(list, stats, slabfile);
else if (major == 1 && minor == 1)
ret = parse_slabinfo11(list, stats, slabfile);
else if (major == 1 && minor == 0)
ret = parse_slabinfo10(list, stats, slabfile);
else {
fprintf(stderr, "unrecognizable slabinfo version\n");
fclose(slabfile);
return 1;
}
fclose(slabfile);
return ret;
}