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replace /proc scanning code by more versatile one.

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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
This commit is contained in:
Denis Vlasenko
2006-11-05 00:43:51 +00:00
parent fa07680091
commit 459e4d6cf7
6 changed files with 329 additions and 172 deletions
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144
procps/top.c
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@@ -30,37 +30,76 @@
#include "busybox.h"
typedef int (*cmp_t)(procps_status_t *P, procps_status_t *Q);
static procps_status_t *top; /* Hehe */
typedef struct {
unsigned long rss;
#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;
static top_status_t *top;
static int ntop;
/* This structure stores some critical information from one frame to
the next. Used for finding deltas. */
struct save_hist {
unsigned long ticks;
unsigned pid;
};
static struct save_hist *prev_hist;
static int prev_hist_count;
/* static int hist_iterations; */
static unsigned total_pcpu;
/* static unsigned long total_rss; */
#define OPT_BATCH_MODE (option_mask32 & 0x4)
#if ENABLE_FEATURE_USE_TERMIOS
static int pid_sort(procps_status_t *P, procps_status_t *Q)
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(procps_status_t *P, procps_status_t *Q)
static int mem_sort(top_status_t *P, top_status_t *Q)
{
return (int)(Q->rss - P->rss);
/* We want to avoid unsigned->signed and truncation errors */
if (Q->rss < P->rss) return -1;
return Q->rss != P->rss; /* 0 if ==, 1 if > */
}
#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
#if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
static cmp_funcp sort_function;
#else
enum { SORT_DEPTH = 3 };
static cmp_t sort_function[SORT_DEPTH];
static int pcpu_sort(procps_status_t *P, procps_status_t *Q)
static cmp_funcp sort_function[SORT_DEPTH];
static int pcpu_sort(top_status_t *P, top_status_t *Q)
{
return (Q->pcpu - P->pcpu);
/* 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(procps_status_t *P, procps_status_t *Q)
static int time_sort(top_status_t *P, top_status_t *Q)
{
return (int)((Q->stime + Q->utime) - (P->stime + P->utime));
/* 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) {
@@ -74,24 +113,6 @@ static int mult_lvl_cmp(void* a, void* b) {
return 0;
}
/* This structure stores some critical information from one frame to
the next. Mostly used for sorting. */
struct save_hist {
int ticks;
pid_t pid;
};
/*
* Calculates percent cpu usage for each task.
*/
static struct save_hist *prev_hist;
static int prev_hist_count;
/* static int hist_iterations; */
static unsigned total_pcpu;
/* static unsigned long total_rss; */
typedef struct {
unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
@@ -115,11 +136,12 @@ static void get_jiffy_counts(void)
jif.busy = jif.total - jif.idle - jif.iowait;
}
static void do_stats(void)
{
procps_status_t *cur;
top_status_t *cur;
pid_t pid;
int total_time, i, last_i, n;
int i, last_i, n;
struct save_hist *new_hist;
get_jiffy_counts();
@@ -139,8 +161,7 @@ static void do_stats(void)
* and system time
*/
pid = cur->pid;
total_time = cur->stime + cur->utime;
new_hist[n].ticks = total_time;
new_hist[n].ticks = cur->ticks;
new_hist[n].pid = pid;
/* find matching entry from previous pass */
@@ -150,13 +171,13 @@ static void do_stats(void)
last_i = i;
if (prev_hist_count) do {
if (prev_hist[i].pid == pid) {
cur->pcpu = total_time - prev_hist[i].ticks;
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_pcpu += cur->pcpu;
/* total_rss += cur->rss; */
}
@@ -167,10 +188,9 @@ static void do_stats(void)
prev_hist = new_hist;
prev_hist_count = ntop;
}
#else
static cmp_t sort_function;
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
/* display generic info (meminfo / loadavg) */
static unsigned long display_generic(int scr_width)
{
@@ -265,7 +285,7 @@ static void display_status(int count, int scr_width)
bits_per_int = sizeof(int)*8
};
procps_status_t *s = top;
top_status_t *s = top;
char rss_str_buf[8];
unsigned long total_memory = display_generic(scr_width); /* or use total_rss? */
unsigned pmem_shift, pmem_scale;
@@ -333,14 +353,19 @@ static void display_status(int count, int scr_width)
sprintf(rss_str_buf, "%6ldM", s->rss/1024);
else
sprintf(rss_str_buf, "%7ld", s->rss);
USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10);)
col -= printf("\n%5u %-8s %s %s%6u%3u.%c" \
USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c") " ",
(unsigned)s->pid, s->user, s->state, rss_str_buf, (unsigned)s->ppid,
USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(
pcpu = div((s->pcpu*pcpu_scale) >> pcpu_shift, 10);
)
col -= printf("\n%5u %-8s %s "
"%s%6u"
USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE("%3u.%c")
"%3u.%c ",
s->pid, get_cached_username(s->uid), s->state,
rss_str_buf, s->ppid,
USE_FEATURE_TOP_CPU_USAGE_PERCENTAGE(pcpu.quot, '0'+pcpu.rem,)
pmem.quot, '0'+pmem.rem);
if (col > 0)
printf("%.*s", col, s->short_cmd);
printf("%.*s", col, s->comm);
/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
s++;
@@ -350,18 +375,20 @@ static void display_status(int count, int scr_width)
fflush(stdout);
}
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 struct termios initial_settings;
static void reset_term(void)
@@ -427,7 +454,7 @@ int top_main(int argc, char **argv)
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
while (1) {
procps_status_t *p;
procps_status_t *p = NULL;
/* Default to 25 lines - 5 lines for status */
lines = 24 - 3;
@@ -442,11 +469,26 @@ int top_main(int argc, char **argv)
#endif /* FEATURE_USE_TERMIOS */
/* read process IDs & status for all the processes */
while ((p = procps_scan(0)) != 0) {
while ((p = procps_scan(p, 0
| PSSCAN_PID
| PSSCAN_PPID
| PSSCAN_RSS
| PSSCAN_STIME
| PSSCAN_UTIME
| PSSCAN_STATE
| PSSCAN_COMM
| PSSCAN_SID
| PSSCAN_UIDGID
))) {
int n = ntop;
top = xrealloc(top, (++ntop)*sizeof(procps_status_t));
memcpy(top + n, p, sizeof(procps_status_t));
top = xrealloc(top, (++ntop)*sizeof(top_status_t));
top[n].pid = p->pid;
top[n].ppid = p->ppid;
top[n].rss = p->rss;
top[n].ticks = p->stime + p->utime;
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("can't find process info in /proc");
@@ -459,9 +501,9 @@ int top_main(int argc, char **argv)
continue;
}
do_stats();
qsort(top, ntop, sizeof(procps_status_t), (void*)mult_lvl_cmp);
qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
#else
qsort(top, ntop, sizeof(procps_status_t), (void*)sort_function);
qsort(top, ntop, sizeof(top_status_t), (void*)sort_function);
#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
count = lines;
if (OPT_BATCH_MODE || count > ntop) {