busybox/procps/top.c
Denis Vlasenko 98ebab8b76 top,ps: improve /proc/PID/cmdinfo reading code
function                                             old     new   delta
display_status                                         -    1231   +1231
read_cmdline                                           -     101    +101
parse_conf                                          1284    1303     +19
arith                                               2033    2042      +9
collect_blk                                          467     474      +7
fsck_main                                           1909    1911      +2
dhcprelay_main                                      1125    1122      -3
singlemount                                         4555    4547      -8
read_close                                            50      36     -14
get_lcm                                              123     105     -18
ed_main                                             3111    3084     -27
func_args                                             73      28     -45
procps_scan                                          732     658     -74
top_main                                            2187     899   -1288
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 4/8 up/down: 1369/-1477)       Total: -108 bytes
   text    data     bss     dec     hex filename
 676048    2744   13968  692760   a9218 busybox_old
 675940    2744   13968  692652   a91ac busybox_unstripped
2007-06-30 14:47:41 +00:00

655 lines
17 KiB
C

/* vi: set sw=4 ts=4: */
/*
* A tiny 'top' utility.
*
* This is written specifically for the linux /proc/<PID>/stat(m)
* files format.
* This reads the PIDs of all processes and their status and shows
* the status of processes (first ones that fit to screen) at given
* intervals.
*
* NOTES:
* - At startup this changes to /proc, all the reads are then
* relative to that.
*
* (C) Eero Tamminen <oak at welho dot com>
*
* Rewritten by Vladimir Oleynik (C) 2002 <dzo@simtreas.ru>
*/
/* Original code Copyrights */
/*
* Copyright (c) 1992 Branko Lankester
* Copyright (c) 1992 Roger Binns
* Copyright (C) 1994-1996 Charles L. Blake.
* Copyright (C) 1992-1998 Michael K. Johnson
* May be distributed under the conditions of the
* GNU Library General Public License
*/
#include "libbb.h"
typedef struct top_status_t {
unsigned long vsz;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
unsigned long ticks;
unsigned pcpu; /* delta of ticks */
#endif
unsigned pid, ppid;
unsigned uid;
char state[4];
char comm[COMM_LEN];
} top_status_t;
typedef struct jiffy_counts_t {
unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
unsigned long long total;
unsigned long long busy;
} jiffy_counts_t;
/* This structure stores some critical information from one frame to
the next. Used for finding deltas. */
typedef struct save_hist {
unsigned long ticks;
unsigned pid;
} save_hist;
typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
enum { SORT_DEPTH = 3 };
struct globals {
top_status_t *top;
int ntop;
#if ENABLE_FEATURE_USE_TERMIOS
struct termios initial_settings;
#endif
#if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
cmp_funcp sort_function;
#else
cmp_funcp sort_function[SORT_DEPTH];
struct save_hist *prev_hist;
int prev_hist_count;
jiffy_counts_t jif, prev_jif;
/* int hist_iterations; */
unsigned total_pcpu;
/* unsigned long total_vsz; */
#endif
};
#define G (*(struct globals*)&bb_common_bufsiz1)
#define top (G.top )
#define ntop (G.ntop )
#if ENABLE_FEATURE_USE_TERMIOS
#define initial_settings (G. initial_settings )
#endif
#define sort_function (G.sort_function )
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
#define prev_hist (G.prev_hist )
#define prev_hist_count (G.prev_hist_count )
#define jif (G.jif )
#define prev_jif (G.prev_jif )
#define total_pcpu (G.total_pcpu )
#endif
#define OPT_BATCH_MODE (option_mask32 & 0x4)
#if ENABLE_FEATURE_USE_TERMIOS
static int pid_sort(top_status_t *P, top_status_t *Q)
{
/* Buggy wrt pids with high bit set */
/* (linux pids are in [1..2^15-1]) */
return (Q->pid - P->pid);
}
#endif
static int mem_sort(top_status_t *P, top_status_t *Q)
{
/* We want to avoid unsigned->signed and truncation errors */
if (Q->vsz < P->vsz) return -1;
return Q->vsz != P->vsz; /* 0 if ==, 1 if > */
}
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
static int pcpu_sort(top_status_t *P, top_status_t *Q)
{
/* Buggy wrt ticks with high bit set */
/* Affects only processes for which ticks overflow */
return (int)Q->pcpu - (int)P->pcpu;
}
static int time_sort(top_status_t *P, top_status_t *Q)
{
/* We want to avoid unsigned->signed and truncation errors */
if (Q->ticks < P->ticks) return -1;
return Q->ticks != P->ticks; /* 0 if ==, 1 if > */
}
static int mult_lvl_cmp(void* a, void* b)
{
int i, cmp_val;
for (i = 0; i < SORT_DEPTH; i++) {
cmp_val = (*sort_function[i])(a, b);
if (cmp_val != 0)
return cmp_val;
}
return 0;
}
static void get_jiffy_counts(void)
{
FILE* fp = xfopen("stat", "r");
prev_jif = jif;
if (fscanf(fp, "cpu %lld %lld %lld %lld %lld %lld %lld %lld",
&jif.usr,&jif.nic,&jif.sys,&jif.idle,
&jif.iowait,&jif.irq,&jif.softirq,&jif.steal) < 4) {
bb_error_msg_and_die("failed to read /proc/stat");
}
fclose(fp);
jif.total = jif.usr + jif.nic + jif.sys + jif.idle
+ jif.iowait + jif.irq + jif.softirq + jif.steal;
/* procps 2.x does not count iowait as busy time */
jif.busy = jif.total - jif.idle - jif.iowait;
}
static void do_stats(void)
{
top_status_t *cur;
pid_t pid;
int i, last_i, n;
struct save_hist *new_hist;
get_jiffy_counts();
total_pcpu = 0;
/* total_vsz = 0; */
new_hist = xmalloc(sizeof(struct save_hist)*ntop);
/*
* Make a pass through the data to get stats.
*/
/* hist_iterations = 0; */
i = 0;
for (n = 0; n < ntop; n++) {
cur = top + n;
/*
* Calculate time in cur process. Time is sum of user time
* and system time
*/
pid = cur->pid;
new_hist[n].ticks = cur->ticks;
new_hist[n].pid = pid;
/* find matching entry from previous pass */
cur->pcpu = 0;
/* do not start at index 0, continue at last used one
* (brought hist_iterations from ~14000 down to 172) */
last_i = i;
if (prev_hist_count) do {
if (prev_hist[i].pid == pid) {
cur->pcpu = cur->ticks - prev_hist[i].ticks;
total_pcpu += cur->pcpu;
break;
}
i = (i+1) % prev_hist_count;
/* hist_iterations++; */
} while (i != last_i);
/* total_vsz += cur->vsz; */
}
/*
* Save cur frame's information.
*/
free(prev_hist);
prev_hist = new_hist;
prev_hist_count = ntop;
}
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
/* display generic info (meminfo / loadavg) */
static unsigned long display_generic(int scr_width)
{
FILE *fp;
char buf[80];
char scrbuf[80];
char *end;
unsigned long total, used, mfree, shared, buffers, cached;
/* read memory info */
fp = xfopen("meminfo", "r");
/*
* Old kernels (such as 2.4.x) had a nice summary of memory info that
* we could parse, however this is gone entirely in 2.6. Try parsing
* the old way first, and if that fails, parse each field manually.
*
* First, we read in the first line. Old kernels will have bogus
* strings we don't care about, whereas new kernels will start right
* out with MemTotal:
* -- PFM.
*/
if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
fgets(buf, sizeof(buf), fp); /* skip first line */
fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
&total, &used, &mfree, &shared, &buffers, &cached);
/* convert to kilobytes */
used /= 1024;
mfree /= 1024;
shared /= 1024;
buffers /= 1024;
cached /= 1024;
total /= 1024;
} else {
/*
* Revert to manual parsing, which incidentally already has the
* sizes in kilobytes. This should be safe for both 2.4 and
* 2.6.
*/
fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
/*
* MemShared: is no longer present in 2.6. Report this as 0,
* to maintain consistent behavior with normal procps.
*/
if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
shared = 0;
fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
fscanf(fp, "Cached: %lu %s\n", &cached, buf);
used = total - mfree;
}
fclose(fp);
/* read load average as a string */
buf[0] = '\0';
open_read_close("loadavg", buf, sizeof(buf));
end = strchr(buf, ' ');
if (end) end = strchr(end+1, ' ');
if (end) end = strchr(end+1, ' ');
if (end) *end = '\0';
/* output memory info and load average */
/* clear screen & go to top */
if (scr_width > sizeof(scrbuf))
scr_width = sizeof(scrbuf);
snprintf(scrbuf, scr_width,
"Mem: %ldK used, %ldK free, %ldK shrd, %ldK buff, %ldK cached",
used, mfree, shared, buffers, cached);
printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
if (ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS) {
/*
* xxx% = (jif.xxx - prev_jif.xxx) / (jif.total - prev_jif.total) * 100%
*/
/* using (unsigned) cast to make multiplication cheaper: */
#if ENABLE_FEATURE_TOP_DECIMALS
/* Generated code is approx +0.5k */
#define CALC_STAT(xxx) div_t xxx = div(1000 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff, 10)
#define SHOW_STAT(xxx) xxx.quot, '0'+xxx.rem
#define FMT "%3u.%c%%"
#else
#define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff
#define SHOW_STAT(xxx) xxx
#define FMT "%3u%%"
#endif
unsigned total_diff = (jif.total - prev_jif.total ? : 1);
CALC_STAT(usr);
CALC_STAT(sys);
CALC_STAT(nic);
CALC_STAT(idle);
CALC_STAT(iowait);
CALC_STAT(irq);
CALC_STAT(softirq);
//CALC_STAT(steal);
snprintf(scrbuf, scr_width,
/* Barely fits in 79 chars when in "decimals" mode.
* %3u in practice almost never displays "100"
* and thus has implicit leading space: " 99" */
"CPU:"FMT" usr"FMT" sys"FMT" nice"FMT" idle"FMT" io"FMT" irq"FMT" softirq",
SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
//, SHOW_STAT(steal) - what is this 'steal' thing?
// I doubt anyone wants to know it
);
puts(scrbuf);
#undef SHOW_STAT
#undef CALC_STAT
#undef FMT
}
snprintf(scrbuf, scr_width, "Load average: %s", buf);
puts(scrbuf);
return total;
}
#if ENABLE_FEATURE_TOP_DECIMALS
#define UPSCALE 1000
#define CALC_STAT(name, val) div_t name = div((val), 10)
#define SHOW_STAT(name) name.quot, '0'+name.rem
#define FMT "%3u.%c"
#else
#define UPSCALE 100
#define CALC_STAT(name, val) unsigned name = (val)
#define SHOW_STAT(name) name
#define FMT " %3u%%"
#endif
/* display process statuses */
static void display_status(int count, int scr_width)
{
enum {
BITS_PER_INT = sizeof(int)*8
};
top_status_t *s = top;
char vsz_str_buf[8];
unsigned long total_memory = display_generic(scr_width); /* or use total_vsz? */
/* xxx_shift and xxx_scale variables allow us to replace
* expensive divides with multiply and shift */
unsigned pmem_shift, pmem_scale, pmem_half;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
unsigned pcpu_shift, pcpu_scale, pcpu_half;
unsigned busy_jifs;
/* what info of the processes is shown */
printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
" PID PPID USER STAT VSZ %MEM %CPU COMMAND");
#define MIN_WIDTH \
sizeof( " PID PPID USER STAT VSZ %MEM %CPU C")
#else
/* !CPU_USAGE_PERCENTAGE */
printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
" PID PPID USER STAT VSZ %MEM COMMAND");
#define MIN_WIDTH \
sizeof( " PID PPID USER STAT VSZ %MEM C")
#endif
/*
* MEM% = s->vsz/MemTotal
*/
pmem_shift = BITS_PER_INT-11;
pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
/* s->vsz is in kb. we want (s->vsz * pmem_scale) to never overflow */
while (pmem_scale >= 512) {
pmem_scale /= 4;
pmem_shift -= 2;
}
pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
busy_jifs = jif.busy - prev_jif.busy;
/* This happens if there were lots of short-lived processes
* between two top updates (e.g. compilation) */
if (total_pcpu < busy_jifs) total_pcpu = busy_jifs;
/*
* CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
* (pcpu is delta of sys+user time between samples)
*/
/* (jif.xxx - prev_jif.xxx) and s->pcpu are
* in 0..~64000 range (HZ*update_interval).
* we assume that unsigned is at least 32-bit.
*/
pcpu_shift = 6;
pcpu_scale = (UPSCALE*64*(uint16_t)busy_jifs ? : 1);
while (pcpu_scale < (1U<<(BITS_PER_INT-2))) {
pcpu_scale *= 4;
pcpu_shift += 2;
}
pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
/* we want (s->pcpu * pcpu_scale) to never overflow */
while (pcpu_scale >= 1024) {
pcpu_scale /= 4;
pcpu_shift -= 2;
}
pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
/* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
#endif
/* Ok, all prelim data is ready, go thru the list */
while (count-- > 0) {
int col = scr_width;
CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
#endif
if (s->vsz >= 100*1024)
sprintf(vsz_str_buf, "%6ldM", s->vsz/1024);
else
sprintf(vsz_str_buf, "%7ld", s->vsz);
// PID PPID USER STAT VSZ %MEM [%CPU] COMMAND
col -= printf("\n" "%5u%6u %-8s %s%s" FMT
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
FMT
#endif
" ",
s->pid, s->ppid, get_cached_username(s->uid),
s->state, vsz_str_buf,
SHOW_STAT(pmem)
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
, SHOW_STAT(pcpu)
#endif
);
if (col > 0) {
char buf[col + 1];
read_cmdline(buf, col, s->pid, s->comm);
fputs(buf, stdout);
}
/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
s++;
}
/* printf(" %d", hist_iterations); */
putchar(OPT_BATCH_MODE ? '\n' : '\r');
fflush(stdout);
}
#undef SHOW_STAT
#undef CALC_STAT
#undef FMT
static void clearmems(void)
{
clear_username_cache();
free(top);
top = 0;
ntop = 0;
}
#if ENABLE_FEATURE_USE_TERMIOS
#include <termios.h>
#include <signal.h>
static void reset_term(void)
{
tcsetattr(0, TCSANOW, (void *) &initial_settings);
#if ENABLE_FEATURE_CLEAN_UP
clearmems();
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
free(prev_hist);
#endif
#endif /* FEATURE_CLEAN_UP */
}
static void sig_catcher(int sig ATTRIBUTE_UNUSED)
{
reset_term();
exit(1);
}
#endif /* FEATURE_USE_TERMIOS */
int top_main(int argc, char **argv);
int top_main(int argc, char **argv)
{
int count, lines, col;
unsigned interval = 5; /* default update rate is 5 seconds */
unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
char *sinterval, *siterations;
#if ENABLE_FEATURE_USE_TERMIOS
struct termios new_settings;
struct timeval tv;
fd_set readfds;
unsigned char c;
#endif /* FEATURE_USE_TERMIOS */
interval = 5;
/* do normal option parsing */
opt_complementary = "-";
getopt32(argc, argv, "d:n:b", &sinterval, &siterations);
if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
//if (option_mask32 & 0x4) // -b
/* change to /proc */
xchdir("/proc");
#if ENABLE_FEATURE_USE_TERMIOS
tcgetattr(0, (void *) &initial_settings);
memcpy(&new_settings, &initial_settings, sizeof(struct termios));
/* unbuffered input, turn off echo */
new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
signal(SIGTERM, sig_catcher);
signal(SIGINT, sig_catcher);
tcsetattr(0, TCSANOW, (void *) &new_settings);
atexit(reset_term);
#endif /* FEATURE_USE_TERMIOS */
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
sort_function[0] = pcpu_sort;
sort_function[1] = mem_sort;
sort_function[2] = time_sort;
#else
sort_function = mem_sort;
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
while (1) {
procps_status_t *p = NULL;
/* Default to 25 lines - 5 lines for status */
lines = 24 - 3 USE_FEATURE_TOP_CPU_GLOBAL_PERCENTS( - 1);
col = 79;
#if ENABLE_FEATURE_USE_TERMIOS
get_terminal_width_height(0, &col, &lines);
if (lines < 5 || col < MIN_WIDTH) {
sleep(interval);
continue;
}
lines -= 3 USE_FEATURE_TOP_CPU_GLOBAL_PERCENTS( + 1);
#endif /* FEATURE_USE_TERMIOS */
/* read process IDs & status for all the processes */
while ((p = procps_scan(p, 0
| PSSCAN_PID
| PSSCAN_PPID
| PSSCAN_VSZ
| PSSCAN_STIME
| PSSCAN_UTIME
| PSSCAN_STATE
| PSSCAN_COMM
| PSSCAN_SID
| PSSCAN_UIDGID
))) {
int n = ntop;
top = xrealloc(top, (++ntop) * sizeof(*top));
top[n].pid = p->pid;
top[n].ppid = p->ppid;
top[n].vsz = p->vsz;
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
top[n].ticks = p->stime + p->utime;
#endif
top[n].uid = p->uid;
strcpy(top[n].state, p->state);
strcpy(top[n].comm, p->comm);
}
if (ntop == 0) {
bb_error_msg_and_die("no process info in /proc");
}
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
if (!prev_hist_count) {
do_stats();
sleep(1);
clearmems();
continue;
}
do_stats();
/* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
#else
qsort(top, ntop, sizeof(top_status_t), (void*)sort_function);
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
count = lines;
if (OPT_BATCH_MODE || count > ntop) {
count = ntop;
}
/* show status for each of the processes */
display_status(count, col);
#if ENABLE_FEATURE_USE_TERMIOS
tv.tv_sec = interval;
tv.tv_usec = 0;
FD_ZERO(&readfds);
FD_SET(0, &readfds);
select(1, &readfds, NULL, NULL, &tv);
if (FD_ISSET(0, &readfds)) {
if (read(0, &c, 1) <= 0) { /* signal */
return EXIT_FAILURE;
}
if (c == 'q' || c == initial_settings.c_cc[VINTR])
break;
if (c == 'M') {
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
sort_function[0] = mem_sort;
sort_function[1] = pcpu_sort;
sort_function[2] = time_sort;
#else
sort_function = mem_sort;
#endif
}
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
if (c == 'P') {
sort_function[0] = pcpu_sort;
sort_function[1] = mem_sort;
sort_function[2] = time_sort;
}
if (c == 'T') {
sort_function[0] = time_sort;
sort_function[1] = mem_sort;
sort_function[2] = pcpu_sort;
}
#endif
if (c == 'N') {
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
sort_function[0] = pid_sort;
#else
sort_function = pid_sort;
#endif
}
}
if (!--iterations)
break;
#else
sleep(interval);
#endif /* FEATURE_USE_TERMIOS */
clearmems();
}
if (ENABLE_FEATURE_CLEAN_UP)
clearmems();
putchar('\n');
return EXIT_SUCCESS;
}