irqbalance-cputree-parse.patch

   1 diff -up irqbalance-0.55/irqbalance-0.55/cputree.c.orig irqbalance-0.55/irqbalance-0.55/cputree.c
   2 --- irqbalance-0.55/irqbalance-0.55/cputree.c.orig      2006-12-10 15:04:59.000000000 -0500
   3 +++ irqbalance-0.55/irqbalance-0.55/cputree.c   2007-09-28 12:43:35.000000000 -0400
   4 @@ -26,6 +26,8 @@
   5
   6  #define _GNU_SOURCE
   7
   8 +#include <ctype.h>
   9 +#include <fcntl.h>
  10  #include <stdio.h>
  11  #include <stdlib.h>
  12  #include <unistd.h>
  13 @@ -131,34 +133,30 @@ static void fill_cache_domain(void)
  14  }
  15
  16
  17 -static void do_one_cpu(char *path)
  18 +static void do_one_cpu(int dfd, char *d_name)
  19  {
  20         struct cpu_core *cpu;
  21         FILE *file;
  22         char new_path[PATH_MAX];
  23
  24         /* skip offline cpus */
  25 -       snprintf(new_path, PATH_MAX, "%s/online", path);
  26 -       file = fopen(new_path, "r");
  27 -       if (file) {
  28 -               char *line = NULL;
  29 -               size_t size = 0;
  30 -               if (getline(&line, &size, file)==0)
  31 +       snprintf(new_path, PATH_MAX, "%s/online", d_name);
  32 +       int fd = openat(dfd, new_path, O_RDONLY);
  33 +       if (fd != -1) {
  34 +               char buf[1];
  35 +               ssize_t n = read(fd, buf, sizeof(buf));
  36 +               close(fd);
  37 +               if (n != sizeof(buf))
  38                         return;
  39 -               fclose(file);
  40 -               if (line && line[0]=='0') {
  41 -                       free(line);
  42 +               if (buf[0] == '0')
  43                         return;
  44 -               }
  45 -               free(line);
  46         }
  47
  48 -       cpu = malloc(sizeof(struct cpu_core));
  49 +       cpu = calloc(1, sizeof(struct cpu_core));
  50         if (!cpu)
  51                 return;
  52 -       memset(cpu, 0, sizeof(struct cpu_core));
  53
  54 -       cpu->number = strtoul(&path[27], NULL, 10);
  55 +       cpu->number = strtoul(&d_name[3], NULL, 10);
  56
  57         cpu_set(cpu->number, cpu->mask);
  58
  59 @@ -170,43 +168,45 @@ static void do_one_cpu(char *path)
  60                 return;
  61         }
  62
  63 +       char *line = NULL;
  64 +       size_t size = 0;
  65
  66         /* try to read the package mask; if it doesn't exist assume solitary */
  67 -       snprintf(new_path, PATH_MAX, "%s/topology/core_siblings", path);
  68 -       file = fopen(new_path, "r");
  69 +       snprintf(new_path, PATH_MAX, "%s/topology/core_siblings", d_name);
  70 +       fd = openat(dfd, new_path, O_RDONLY);
  71 +       file = fd == -1 ? NULL : fdopen(fd, "r");
  72         cpu_set(cpu->number, cpu->package_mask);
  73         if (file) {
  74 -               char *line = NULL;
  75 -               size_t size = 0;
  76                 if (getline(&line, &size, file))
  77                         cpumask_parse_user(line, strlen(line), cpu->package_mask);
  78                 fclose(file);
  79 -               free(line);
  80 -       }
  81 +       } else if (fd != -1)
  82 +               close(fd);
  83
  84         /* try to read the cache mask; if it doesn't exist assume solitary */
  85         /* We want the deepest cache level available so try index1 first, then index2 */
  86         cpu_set(cpu->number, cpu->cache_mask);
  87 -       snprintf(new_path, PATH_MAX, "%s/cache/index1/shared_cpu_map", path);
  88 -       file = fopen(new_path, "r");
  89 +       snprintf(new_path, PATH_MAX, "%s/cache/index1/shared_cpu_map", d_name);
  90 +       fd = openat(dfd, new_path, O_RDONLY);
  91 +       file = fd == -1 ? NULL : fdopen(fd, "r");
  92         if (file) {
  93 -               char *line = NULL;
  94 -               size_t size = 0;
  95                 if (getline(&line, &size, file))
  96                         cpumask_parse_user(line, strlen(line), cpu->cache_mask);
  97                 fclose(file);
  98 -               free(line);
  99 -       }
 100 -       snprintf(new_path, PATH_MAX, "%s/cache/index2/shared_cpu_map", path);
 101 -       file = fopen(new_path, "r");
 102 +       } else if (fd != -1)
 103 +               close(fd);
 104 +
 105 +       snprintf(new_path, PATH_MAX, "%s/cache/index2/shared_cpu_map", d_name);
 106 +       fd = openat(dfd, new_path, O_RDONLY);
 107 +       file = fd == -1 ? NULL : fdopen(fd, "r");
 108         if (file) {
 109 -               char *line = NULL;
 110 -               size_t size = 0;
 111                 if (getline(&line, &size, file))
 112                         cpumask_parse_user(line, strlen(line), cpu->cache_mask);
 113                 fclose(file);
 114 -               free(line);
 115 -       }
 116 +       } else if (fd != -1)
 117 +               close(fd);
 118 +
 119 +       free(line);
 120
 121         /*
 122            blank out the banned cpus from the various masks so that interrupts
 123 @@ -311,18 +311,19 @@ void parse_cpu_tree(void)
 124  {
 125         DIR *dir;
 126         struct dirent *entry;
 127 +       int dfd;
 128
 129         cpus_complement(unbanned_cpus, banned_cpus);
 130
 131         dir = opendir("/sys/devices/system/cpu");
 132         if (!dir)
 133                 return;
 134 +       dfd = dirfd(dir);
 135         do {
 136                 entry = readdir(dir);
 137 -                if (entry && strlen(entry->d_name)>3 && strstr(entry->d_name,"cpu")) {
 138 -                       char new_path[PATH_MAX];
 139 -                       sprintf(new_path, "/sys/devices/system/cpu/%s", entry->d_name);
 140 -                       do_one_cpu(new_path);
 141 +                if (entry && strlen(entry->d_name)>3 && memcmp(entry->d_name,"cpu",3) == 0
 142 +                   && isdigit(entry->d_name[3])) {
 143 +                       do_one_cpu(dfd, entry->d_name);
 144                 }
 145         } while (entry);
 146         closedir(dir);