From 459e4d6cf77940977a064edab60c7162731554fb Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sun, 5 Nov 2006 00:43:51 +0000 Subject: replace /proc scanning code by more versatile one. Use it where appropriate. Stop scanning /etc/passwd *for every process*!!! (uid->username) top: reduce memory usage - we won't save unneeded fields from /proc info anymore. Downside: ~+250 bytes of code --- libbb/procps.c | 261 +++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 171 insertions(+), 90 deletions(-) (limited to 'libbb/procps.c') diff --git a/libbb/procps.c b/libbb/procps.c index 15f77153a..dee5638e4 100644 --- a/libbb/procps.c +++ b/libbb/procps.c @@ -11,6 +11,35 @@ #include "libbb.h" +typedef struct { + uid_t uid; + char username[12]; +} user_map_t; + +static user_map_t *username_cache; +static int username_cache_size; + +void clear_username_cache(void) +{ + free(username_cache); + username_cache = NULL; + username_cache_size = 0; +} + +const char* get_cached_username(uid_t uid) +{ + int i; + for (i = 0; i < username_cache_size; i++) + if (username_cache[i].uid == uid) + return username_cache[i].username; + i = username_cache_size++; + username_cache = xrealloc(username_cache, username_cache_size * sizeof(*username_cache)); + username_cache[i].uid = uid; + bb_getpwuid(username_cache[i].username, uid, sizeof(username_cache[i].username)); + return username_cache[i].username; +} + + #define PROCPS_BUFSIZE 1024 static int read_to_buf(const char *filename, void *buf) @@ -21,119 +50,171 @@ static int read_to_buf(const char *filename, void *buf) return ret; } +procps_status_t* alloc_procps_scan(int flags) +{ + procps_status_t* sp = xzalloc(sizeof(procps_status_t)); + sp->dir = xopendir("/proc"); + return sp; +} -procps_status_t * procps_scan(int save_user_arg0) +void free_procps_scan(procps_status_t* sp) { - static DIR *dir; - static procps_status_t ret_status; + closedir(sp->dir); + free(sp->cmd); + free(sp); +} +void BUG_comm_size(void); +procps_status_t* procps_scan(procps_status_t* sp, int flags) +{ struct dirent *entry; - char *name; char buf[PROCPS_BUFSIZE]; - char status[sizeof("/proc//cmdline") + sizeof(int)*3]; - char *status_tail; - procps_status_t curstatus; + char filename[sizeof("/proc//cmdline") + sizeof(int)*3]; + char *filename_tail; long tasknice; - int pid; + unsigned pid; int n; struct stat sb; - if (!dir) { - dir = xopendir("/proc"); - } + if (!sp) + sp = alloc_procps_scan(flags); + for (;;) { - entry = readdir(dir); + entry = readdir(sp->dir); if (entry == NULL) { - closedir(dir); - dir = 0; - return 0; + free_procps_scan(sp); + return NULL; } - name = entry->d_name; - if (!(*name >= '0' && *name <= '9')) + if (safe_strtou(entry->d_name, &pid)) continue; - memset(&curstatus, 0, sizeof(procps_status_t)); - pid = atoi(name); - curstatus.pid = pid; + /* After this point we have to break, not continue + * ("continue" would mean that current /proc/NNN + * is not a valid process info) */ - status_tail = status + sprintf(status, "/proc/%d", pid); - if (stat(status, &sb)) - continue; - bb_getpwuid(curstatus.user, sb.st_uid, sizeof(curstatus.user)); + memset(&sp->rss, 0, sizeof(*sp) - offsetof(procps_status_t, rss)); - /* see proc(5) for some details on this */ - strcpy(status_tail, "/stat"); - n = read_to_buf(status, buf); - if (n < 0) - continue; - name = strrchr(buf, ')'); /* split into "PID (cmd" and "" */ - if (name == 0 || name[1] != ' ') - continue; - *name = 0; - sscanf(buf, "%*s (%15c", curstatus.short_cmd); - n = sscanf(name+2, - "%c %d " - "%*s %*s %*s %*s " /* pgrp, session, tty, tpgid */ - "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */ -#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE - "%lu %lu " /* utime, stime */ -#else - "%*s %*s " /* utime, stime */ -#endif - "%*s %*s %*s " /* cutime, cstime, priority */ - "%ld " /* nice */ - "%*s %*s %*s " /* timeout, it_real_value, start_time */ - "%*s " /* vsize */ - "%ld", /* rss */ - curstatus.state, &curstatus.ppid, -#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE - &curstatus.utime, &curstatus.stime, -#endif - &tasknice, - &curstatus.rss); -#ifdef CONFIG_FEATURE_TOP_CPU_USAGE_PERCENTAGE - if (n != 6) -#else - if (n != 4) -#endif - continue; + sp->pid = pid; + if (!(flags & ~PSSCAN_PID)) break; - if (curstatus.rss == 0 && curstatus.state[0] != 'Z') - curstatus.state[1] = 'W'; - else - curstatus.state[1] = ' '; - if (tasknice < 0) - curstatus.state[2] = '<'; - else if (tasknice > 0) - curstatus.state[2] = 'N'; - else - curstatus.state[2] = ' '; + filename_tail = filename + sprintf(filename, "/proc/%d", pid); + + if (flags & PSSCAN_UIDGID) { + if (stat(filename, &sb)) + break; + /* Need comment - is this effective or read UID/GID? */ + sp->uid = sb.st_uid; + sp->gid = sb.st_gid; + } + + if (flags & PSSCAN_STAT) { + char *cp; + /* see proc(5) for some details on this */ + strcpy(filename_tail, "/stat"); + n = read_to_buf(filename, buf); + if (n < 0) + break; + cp = strrchr(buf, ')'); /* split into "PID (cmd" and "" */ + if (!cp || cp[1] != ' ') + break; + cp[0] = '\0'; + if (sizeof(sp->comm) < 16) + BUG_comm_size(); + sscanf(buf, "%*s (%15c", sp->comm); + n = sscanf(cp+2, + "%c %u " /* state, ppid */ + "%u %u %*s %*s " /* pgid, sid, tty, tpgid */ + "%*s %*s %*s %*s %*s " /* flags, min_flt, cmin_flt, maj_flt, cmaj_flt */ + "%lu %lu " /* utime, stime */ + "%*s %*s %*s " /* cutime, cstime, priority */ + "%ld " /* nice */ + "%*s %*s %*s " /* timeout, it_real_value, start_time */ + "%*s " /* vsize */ + "%lu", /* rss */ + sp->state, &sp->ppid, + &sp->pgid, &sp->sid, + &sp->utime, &sp->stime, + &tasknice, + &sp->rss); + if (n != 8) + break; + + if (sp->rss == 0 && sp->state[0] != 'Z') + sp->state[1] = 'W'; + else + sp->state[1] = ' '; + if (tasknice < 0) + sp->state[2] = '<'; + else if (tasknice > 0) + sp->state[2] = 'N'; + else + sp->state[2] = ' '; #ifdef PAGE_SHIFT - curstatus.rss <<= (PAGE_SHIFT - 10); /* 2**10 = 1kb */ + sp->rss <<= (PAGE_SHIFT - 10); /* 2**10 = 1kb */ #else - curstatus.rss *= (getpagesize() >> 10); /* 2**10 = 1kb */ + sp->rss *= (getpagesize() >> 10); /* 2**10 = 1kb */ #endif + } - if (save_user_arg0) { - strcpy(status_tail, "/cmdline"); - n = read_to_buf(status, buf); - if (n > 0) { - if (buf[n-1]=='\n') - buf[--n] = 0; - name = buf; - while (n) { - if (((unsigned char)*name) < ' ') - *name = ' '; - name++; - n--; - } - *name = 0; - if (buf[0]) - curstatus.cmd = strdup(buf); - /* if NULL it work true also */ + if (flags & PSSCAN_CMD) { + free(sp->cmd); + sp->cmd = NULL; + strcpy(filename_tail, "/cmdline"); + n = read_to_buf(filename, buf); + if (n <= 0) + break; + if (buf[n-1] == '\n') { + if (!--n) + break; + buf[n] = '\0'; } + do { + n--; + if ((unsigned char)(buf[n]) < ' ') + buf[n] = ' '; + } while (n); + sp->cmd = strdup(buf); } - return memcpy(&ret_status, &curstatus, sizeof(procps_status_t)); + break; } + return sp; } +/* from kernel: + // pid comm S ppid pgid sid tty_nr tty_pgrp flg + sprintf(buffer,"%d (%s) %c %d %d %d %d %d %lu %lu \ +%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \ +%lu %lu %lu %lu %lu %lu %lu %lu %d %d %lu %lu %llu\n", + task->pid, + tcomm, + state, + ppid, + pgid, + sid, + tty_nr, + tty_pgrp, + task->flags, + min_flt, + + cmin_flt, + maj_flt, + cmaj_flt, + cputime_to_clock_t(utime), + cputime_to_clock_t(stime), + cputime_to_clock_t(cutime), + cputime_to_clock_t(cstime), + priority, + nice, + num_threads, + // 0, + start_time, + vsize, + mm ? get_mm_rss(mm) : 0, + rsslim, + mm ? mm->start_code : 0, + mm ? mm->end_code : 0, + mm ? mm->start_stack : 0, + esp, + eip, +the rest is some obsolete cruft +*/ -- cgit v1.2.3