Bump to version 1.22.1
[platform/upstream/busybox.git] / procps / top.c
index 206f9e8..51f1c1a 100644 (file)
@@ -4,7 +4,7 @@
  *
  * 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.
  * (C) Eero Tamminen <oak at welho dot com>
  *
  * Rewritten by Vladimir Oleynik (C) 2002 <dzo@simtreas.ru>
- */
-
-/* Original code Copyrights */
-/*
+ *
+ * Sept 2008: Vineet Gupta <vineet.gupta@arc.com>
+ * Added Support for reporting SMP Information
+ * - CPU where process was last seen running
+ *   (to see effect of sched_setaffinity() etc)
+ * - CPU time split (idle/IO/wait etc) per CPU
+ *
  * 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
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+/* How to snapshot /proc for debugging top problems:
+ * for f in /proc/[0-9]*""/stat; do
+ *         n=${f#/proc/}
+ *         n=${n%/stat}_stat
+ *         cp $f $n
+ * done
+ * cp /proc/stat /proc/meminfo /proc/loadavg .
+ * top -bn1 >top.out
+ *
+ * ...and how to run top on it on another machine:
+ * rm -rf proc; mkdir proc
+ * for f in [0-9]*_stat; do
+ *         p=${f%_stat}
+ *         mkdir -p proc/$p
+ *         cp $f proc/$p/stat
+ * done
+ * cp stat meminfo loadavg proc
+ * chroot . ./top -bn1 >top1.out
  */
 
+//config:config TOP
+//config:      bool "top"
+//config:      default y
+//config:      help
+//config:        The top program provides a dynamic real-time view of a running
+//config:        system.
+//config:
+//config:config FEATURE_TOP_CPU_USAGE_PERCENTAGE
+//config:      bool "Show CPU per-process usage percentage"
+//config:      default y
+//config:      depends on TOP
+//config:      help
+//config:        Make top display CPU usage for each process.
+//config:        This adds about 2k.
+//config:
+//config:config FEATURE_TOP_CPU_GLOBAL_PERCENTS
+//config:      bool "Show CPU global usage percentage"
+//config:      default y
+//config:      depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
+//config:      help
+//config:        Makes top display "CPU: NN% usr NN% sys..." line.
+//config:        This adds about 0.5k.
+//config:
+//config:config FEATURE_TOP_SMP_CPU
+//config:      bool "SMP CPU usage display ('c' key)"
+//config:      default y
+//config:      depends on FEATURE_TOP_CPU_GLOBAL_PERCENTS
+//config:      help
+//config:        Allow 'c' key to switch between individual/cumulative CPU stats
+//config:        This adds about 0.5k.
+//config:
+//config:config FEATURE_TOP_DECIMALS
+//config:      bool "Show 1/10th of a percent in CPU/mem statistics"
+//config:      default y
+//config:      depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
+//config:      help
+//config:        Show 1/10th of a percent in CPU/mem statistics.
+//config:        This adds about 0.3k.
+//config:
+//config:config FEATURE_TOP_SMP_PROCESS
+//config:      bool "Show CPU process runs on ('j' field)"
+//config:      default y
+//config:      depends on TOP
+//config:      help
+//config:        Show CPU where process was last found running on.
+//config:        This is the 'j' field.
+//config:
+//config:config FEATURE_TOPMEM
+//config:      bool "Topmem command ('s' key)"
+//config:      default y
+//config:      depends on TOP
+//config:      help
+//config:        Enable 's' in top (gives lots of memory info).
+
 #include "libbb.h"
 
 
@@ -41,10 +117,15 @@ typedef struct top_status_t {
        unsigned uid;
        char state[4];
        char comm[COMM_LEN];
+#if ENABLE_FEATURE_TOP_SMP_PROCESS
+       int last_seen_on_cpu;
+#endif
 } top_status_t;
 
 typedef struct jiffy_counts_t {
-       unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
+       /* Linux 2.4.x has only first four */
+       unsigned long long usr, nic, sys, idle;
+       unsigned long long iowait, irq, softirq, steal;
        unsigned long long total;
        unsigned long long busy;
 } jiffy_counts_t;
@@ -53,7 +134,7 @@ typedef struct jiffy_counts_t {
    the next. Used for finding deltas. */
 typedef struct save_hist {
        unsigned long ticks;
-       unsigned pid;
+       pid_t pid;
 } save_hist;
 
 typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
@@ -65,12 +146,20 @@ enum { SORT_DEPTH = 3 };
 struct globals {
        top_status_t *top;
        int ntop;
+       smallint inverted;
 #if ENABLE_FEATURE_TOPMEM
        smallint sort_field;
-       smallint inverted;
 #endif
+#if ENABLE_FEATURE_TOP_SMP_CPU
+       smallint smp_cpu_info; /* one/many cpu info lines? */
+#endif
+       unsigned lines;  /* screen height */
 #if ENABLE_FEATURE_USE_TERMIOS
        struct termios initial_settings;
+       int scroll_ofs;
+#define G_scroll_ofs G.scroll_ofs
+#else
+#define G_scroll_ofs 0
 #endif
 #if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
        cmp_funcp sort_function[1];
@@ -78,41 +167,51 @@ struct globals {
        cmp_funcp sort_function[SORT_DEPTH];
        struct save_hist *prev_hist;
        int prev_hist_count;
-       jiffy_counts_t jif, prev_jif;
+       jiffy_counts_t cur_jif, prev_jif;
        /* int hist_iterations; */
        unsigned total_pcpu;
        /* unsigned long total_vsz; */
 #endif
+#if ENABLE_FEATURE_TOP_SMP_CPU
+       /* Per CPU samples: current and last */
+       jiffy_counts_t *cpu_jif, *cpu_prev_jif;
+       int num_cpus;
+#endif
+#if ENABLE_FEATURE_USE_TERMIOS
+       char kbd_input[KEYCODE_BUFFER_SIZE];
+#endif
        char line_buf[80];
-};
-
+}; //FIX_ALIASING; - large code growth
 enum { LINE_BUF_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line_buf) };
-
 #define G (*(struct globals*)&bb_common_bufsiz1)
-#define INIT_G() \
-       do { \
-               struct G_sizecheck { \
-                       char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \
-               }; \
-       } while (0)
+struct BUG_bad_size {
+       char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1];
+       char BUG_line_buf_too_small[LINE_BUF_SIZE > 80 ? 1 : -1];
+};
 #define top              (G.top               )
 #define ntop             (G.ntop              )
 #define sort_field       (G.sort_field        )
 #define inverted         (G.inverted          )
+#define smp_cpu_info     (G.smp_cpu_info      )
 #define initial_settings (G.initial_settings  )
 #define sort_function    (G.sort_function     )
 #define prev_hist        (G.prev_hist         )
 #define prev_hist_count  (G.prev_hist_count   )
-#define jif              (G.jif               )
+#define cur_jif          (G.cur_jif           )
 #define prev_jif         (G.prev_jif          )
+#define cpu_jif          (G.cpu_jif           )
+#define cpu_prev_jif     (G.cpu_prev_jif      )
+#define num_cpus         (G.num_cpus          )
 #define total_pcpu       (G.total_pcpu        )
 #define line_buf         (G.line_buf          )
+#define INIT_G() do { } while (0)
 
 enum {
        OPT_d = (1 << 0),
        OPT_n = (1 << 1),
        OPT_b = (1 << 2),
-       OPT_EOF = (1 << 3), /* pseudo: "we saw EOF in stdin" */
+       OPT_m = (1 << 3),
+       OPT_EOF = (1 << 4), /* pseudo: "we saw EOF in stdin" */
 };
 #define OPT_BATCH_MODE (option_mask32 & OPT_b)
 
@@ -157,29 +256,89 @@ static int mult_lvl_cmp(void* a, void* b)
        for (i = 0; i < SORT_DEPTH; i++) {
                cmp_val = (*sort_function[i])(a, b);
                if (cmp_val != 0)
-                       return cmp_val;
+                       break;
        }
-       return 0;
+       return inverted ? -cmp_val : cmp_val;
 }
 
+static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
+{
+#if !ENABLE_FEATURE_TOP_SMP_CPU
+       static const char fmt[] = "cpu %llu %llu %llu %llu %llu %llu %llu %llu";
+#else
+       static const char fmt[] = "cp%*s %llu %llu %llu %llu %llu %llu %llu %llu";
+#endif
+       int ret;
+
+       if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
+               return 0;
+       ret = sscanf(line_buf, fmt,
+                       &p_jif->usr, &p_jif->nic, &p_jif->sys, &p_jif->idle,
+                       &p_jif->iowait, &p_jif->irq, &p_jif->softirq,
+                       &p_jif->steal);
+       if (ret >= 4) {
+               p_jif->total = p_jif->usr + p_jif->nic + p_jif->sys + p_jif->idle
+                       + p_jif->iowait + p_jif->irq + p_jif->softirq + p_jif->steal;
+               /* procps 2.x does not count iowait as busy time */
+               p_jif->busy = p_jif->total - p_jif->idle - p_jif->iowait;
+       }
+
+       return ret;
+}
 
 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("can't read /proc/stat");
+       FILE* fp = xfopen_for_read("stat");
+
+       /* We need to parse cumulative counts even if SMP CPU display is on,
+        * they are used to calculate per process CPU% */
+       prev_jif = cur_jif;
+       if (read_cpu_jiffy(fp, &cur_jif) < 4)
+               bb_error_msg_and_die("can't read '%s'", "/proc/stat");
+
+#if !ENABLE_FEATURE_TOP_SMP_CPU
+       fclose(fp);
+       return;
+#else
+       if (!smp_cpu_info) {
+               fclose(fp);
+               return;
        }
+
+       if (!num_cpus) {
+               /* First time here. How many CPUs?
+                * There will be at least 1 /proc/stat line with cpu%d
+                */
+               while (1) {
+                       cpu_jif = xrealloc_vector(cpu_jif, 1, num_cpus);
+                       if (read_cpu_jiffy(fp, &cpu_jif[num_cpus]) <= 4)
+                               break;
+                       num_cpus++;
+               }
+               if (num_cpus == 0) /* /proc/stat with only "cpu ..." line?! */
+                       smp_cpu_info = 0;
+
+               cpu_prev_jif = xzalloc(sizeof(cpu_prev_jif[0]) * num_cpus);
+
+               /* Otherwise the first per cpu display shows all 100% idles */
+               usleep(50000);
+       } else { /* Non first time invocation */
+               jiffy_counts_t *tmp;
+               int i;
+
+               /* First switch the sample pointers: no need to copy */
+               tmp = cpu_prev_jif;
+               cpu_prev_jif = cpu_jif;
+               cpu_jif = tmp;
+
+               /* Get the new samples */
+               for (i = 0; i < num_cpus; i++)
+                       read_cpu_jiffy(fp, &cpu_jif[i]);
+       }
+#endif
        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;
@@ -190,7 +349,7 @@ static void do_stats(void)
        get_jiffy_counts();
        total_pcpu = 0;
        /* total_vsz = 0; */
-       new_hist = xmalloc(sizeof(struct save_hist)*ntop);
+       new_hist = xmalloc(sizeof(new_hist[0]) * ntop);
        /*
         * Make a pass through the data to get stats.
         */
@@ -231,6 +390,7 @@ static void do_stats(void)
        prev_hist = new_hist;
        prev_hist_count = ntop;
 }
+
 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
@@ -258,18 +418,96 @@ static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
 }
 #endif
 
-static unsigned long display_header(int scr_width)
+#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
+static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
+{
+       /*
+        * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
+        */
+       unsigned total_diff;
+       jiffy_counts_t *p_jif, *p_prev_jif;
+       int i;
+# if ENABLE_FEATURE_TOP_SMP_CPU
+       int n_cpu_lines;
+# endif
+
+       /* using (unsigned) casts to make operations cheaper */
+# define  CALC_TOTAL_DIFF do { \
+       total_diff = (unsigned)(p_jif->total - p_prev_jif->total); \
+       if (total_diff == 0) total_diff = 1; \
+} while (0)
+
+# if ENABLE_FEATURE_TOP_DECIMALS
+#  define CALC_STAT(xxx) char xxx[8]
+#  define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
+#  define FMT "%s"
+# else
+#  define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
+#  define SHOW_STAT(xxx) xxx
+#  define FMT "%4u%% "
+# endif
+
+# if !ENABLE_FEATURE_TOP_SMP_CPU
+       {
+               i = 1;
+               p_jif = &cur_jif;
+               p_prev_jif = &prev_jif;
+# else
+       /* Loop thru CPU(s) */
+       n_cpu_lines = smp_cpu_info ? num_cpus : 1;
+       if (n_cpu_lines > *lines_rem_p)
+               n_cpu_lines = *lines_rem_p;
+
+       for (i = 0; i < n_cpu_lines; i++) {
+               p_jif = &cpu_jif[i];
+               p_prev_jif = &cpu_prev_jif[i];
+# endif
+               CALC_TOTAL_DIFF;
+
+               { /* Need a block: CALC_STAT are declarations */
+                       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. */
+# if ENABLE_FEATURE_TOP_SMP_CPU
+                               "CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
+                               (smp_cpu_info ? utoa(i) : ""),
+# else
+                               "CPU:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
+# endif
+                               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
+       *lines_rem_p -= i;
+}
+#else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
+# define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
+#endif
+
+static unsigned long display_header(int scr_width, int *lines_rem_p)
 {
        FILE *fp;
        char buf[80];
        char scrbuf[80];
        unsigned long total, used, mfree, shared, buffers, cached;
-#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
-       unsigned total_diff;
-#endif
 
        /* read memory info */
-       fp = xfopen("meminfo", "r");
+       fp = xfopen_for_read("meminfo");
 
        /*
         * Old kernels (such as 2.4.x) had a nice summary of memory info that
@@ -299,7 +537,6 @@ static unsigned long display_header(int scr_width)
                 * sizes in kilobytes. This should be safe for both 2.4 and
                 * 2.6.
                 */
-
                fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
 
                /*
@@ -317,104 +554,71 @@ static unsigned long display_header(int scr_width)
        fclose(fp);
 
        /* output memory info */
-       if (scr_width > sizeof(scrbuf))
+       if (scr_width > (int)sizeof(scrbuf))
                scr_width = sizeof(scrbuf);
        snprintf(scrbuf, scr_width,
                "Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
                used, mfree, shared, buffers, cached);
-       /* clear screen & go to top */
-       printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
+       /* go to top & clear to the end of screen */
+       printf(OPT_BATCH_MODE ? "%s\n" : "\033[H\033[J%s\n", scrbuf);
+       (*lines_rem_p)--;
 
-#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
-       /*
-        * xxx% = (jif.xxx - prev_jif.xxx) / (jif.total - prev_jif.total) * 100%
+       /* Display CPU time split as percentage of total time
+        * This displays either a cumulative line or one line per CPU
         */
-       /* using (unsigned) casts to make operations cheaper */
-       total_diff = ((unsigned)(jif.total - prev_jif.total) ? : 1);
-#if ENABLE_FEATURE_TOP_DECIMALS
-/* Generated code is approx +0.3k */
-#define CALC_STAT(xxx) char xxx[8]
-#define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(jif.xxx - prev_jif.xxx), total_diff)
-#define FMT "%s"
-#else
-#define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff
-#define SHOW_STAT(xxx) xxx
-#define FMT "%4u%% "
-#endif
-       { /* need block: CALC_STAT are declarations */
-               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. */
-                       "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
-#endif
+       display_cpus(scr_width, scrbuf, lines_rem_p);
 
        /* read load average as a string */
        buf[0] = '\0';
-       open_read_close("loadavg", buf, sizeof("N.NN N.NN N.NN")-1);
-       buf[sizeof("N.NN N.NN N.NN")-1] = '\0';
+       open_read_close("loadavg", buf, sizeof(buf) - 1);
+       buf[sizeof(buf) - 1] = '\n';
+       *strchr(buf, '\n') = '\0';
        snprintf(scrbuf, scr_width, "Load average: %s", buf);
        puts(scrbuf);
+       (*lines_rem_p)--;
 
        return total;
 }
 
-static NOINLINE void display_process_list(int count, int scr_width)
+static NOINLINE void display_process_list(int lines_rem, int scr_width)
 {
        enum {
-               BITS_PER_INT = sizeof(int)*8
+               BITS_PER_INT = sizeof(int) * 8
        };
 
-       top_status_t *s = top;
+       top_status_t *s;
        char vsz_str_buf[8];
-       unsigned long total_memory = display_header(scr_width); /* or use total_vsz? */
+       unsigned long total_memory = display_header(scr_width, &lines_rem); /* 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 tmp_unsigned;
        unsigned pcpu_shift, pcpu_scale, pcpu_half;
        unsigned busy_jifs;
+#endif
 
        /* 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");
-#else
-
-       /* !CPU_USAGE_PERCENTAGE */
-       printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
-               "  PID  PPID USER     STAT   VSZ %MEM COMMAND");
-#endif
+       printf(OPT_BATCH_MODE ? "%.*s" : "\033[7m%.*s\033[0m", scr_width,
+               "  PID  PPID USER     STAT   VSZ %VSZ"
+               IF_FEATURE_TOP_SMP_PROCESS(" CPU")
+               IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
+               " COMMAND");
+       lines_rem--;
 
 #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"
+# 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 "%4u%%"
+# define UPSCALE 100
+# define CALC_STAT(name, val) unsigned name = (val)
+# define SHOW_STAT(name) name
+# define FMT "%4u%%"
 #endif
        /*
-        * MEM% = s->vsz/MemTotal
+        * %VSZ = s->vsz/MemTotal
         */
        pmem_shift = BITS_PER_INT-11;
        pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
@@ -423,9 +627,9 @@ static NOINLINE void display_process_list(int count, int scr_width)
                pmem_scale /= 4;
                pmem_shift -= 2;
        }
-       pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 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;
+       busy_jifs = cur_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;
@@ -434,29 +638,36 @@ static NOINLINE void display_process_list(int count, int scr_width)
         * 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
+       /* (cur_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 = UPSCALE*64 * (uint16_t)busy_jifs;
+       if (pcpu_scale == 0)
+               pcpu_scale = 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);
+       tmp_unsigned = (uint16_t)(cur_jif.total - prev_jif.total) * total_pcpu;
+       if (tmp_unsigned != 0)
+               pcpu_scale /= tmp_unsigned;
        /* 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);
+       pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
        /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 #endif
 
-       scr_width += 2; /* account for leading '\n' and trailing NUL */
        /* Ok, all preliminary data is ready, go through the list */
-       while (count-- > 0) {
+       scr_width += 2; /* account for leading '\n' and trailing NUL */
+       if (lines_rem > ntop - G_scroll_ofs)
+               lines_rem = ntop - G_scroll_ofs;
+       s = top + G_scroll_ofs;
+       while (--lines_rem >= 0) {
                unsigned col;
                CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
@@ -466,31 +677,29 @@ static NOINLINE void display_process_list(int count, int scr_width)
                if (s->vsz >= 100000)
                        sprintf(vsz_str_buf, "%6ldm", s->vsz/1024);
                else
-                       sprintf(vsz_str_buf, "%7ld", s->vsz);
-               // PID PPID USER STAT VSZ %MEM [%CPU] COMMAND
+                       sprintf(vsz_str_buf, "%7lu", s->vsz);
+               /* PID PPID USER STAT VSZ %VSZ [%CPU] COMMAND */
                col = snprintf(line_buf, scr_width,
                                "\n" "%5u%6u %-8.8s %s%s" FMT
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
-                               FMT
-#endif
+                               IF_FEATURE_TOP_SMP_PROCESS(" %3d")
+                               IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
                                " ",
                                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_FEATURE_TOP_SMP_PROCESS(, s->last_seen_on_cpu)
+                               IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
                );
-               if (col + 1 < scr_width)
-                       read_cmdline(line_buf + col, scr_width - col - 1, s->pid, s->comm);
+               if ((int)(col + 1) < scr_width)
+                       read_cmdline(line_buf + col, scr_width - col, s->pid, s->comm);
                fputs(line_buf, stdout);
                /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
-                       jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
+                       cur_jif.busy - prev_jif.busy, cur_jif.total - prev_jif.total); */
                s++;
        }
        /* printf(" %d", hist_iterations); */
        bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
-       fflush(stdout);
+       fflush_all();
 }
 #undef UPSCALE
 #undef SHOW_STAT
@@ -502,29 +711,28 @@ static void clearmems(void)
        clear_username_cache();
        free(top);
        top = NULL;
-       ntop = 0;
 }
 
 #if ENABLE_FEATURE_USE_TERMIOS
-#include <termios.h>
-#include <signal.h>
 
 static void reset_term(void)
 {
-       tcsetattr(0, TCSANOW, &initial_settings);
+       if (!OPT_BATCH_MODE)
+               tcsetattr_stdin_TCSANOW(&initial_settings);
        if (ENABLE_FEATURE_CLEAN_UP) {
                clearmems();
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
                free(prev_hist);
-#endif
+# endif
        }
 }
 
-static void sig_catcher(int sig ATTRIBUTE_UNUSED)
+static void sig_catcher(int sig)
 {
        reset_term();
-       exit(1);
+       kill_myself_with_sig(sig);
 }
+
 #endif /* FEATURE_USE_TERMIOS */
 
 /*
@@ -551,6 +759,7 @@ enum { NUM_SORT_FIELD = 7 };
 #define topmem ((topmem_status_t*)top)
 
 #if ENABLE_FEATURE_TOPMEM
+
 static int topmem_sort(char *a, char *b)
 {
        int n;
@@ -559,141 +768,104 @@ static int topmem_sort(char *a, char *b)
        n = offsetof(topmem_status_t, vsz) + (sort_field * sizeof(mem_t));
        l = *(mem_t*)(a + n);
        r = *(mem_t*)(b + n);
-//     if (l == r) {
-//             l = a->mapped_rw;
-//             r = b->mapped_rw;
-//     }
+       if (l == r) {
+               l = ((topmem_status_t*)a)->dirty;
+               r = ((topmem_status_t*)b)->dirty;
+       }
        /* We want to avoid unsigned->signed and truncation errors */
        /* l>r: -1, l=r: 0, l<r: 1 */
        n = (l > r) ? -1 : (l != r);
        return inverted ? -n : n;
 }
 
-/* Cut "NNNN " out of "    NNNN kb" */
-static char *grab_number(char *str, const char *match, unsigned sz)
-{
-       if (strncmp(str, match, sz) == 0) {
-               str = skip_whitespace(str + sz);
-               (skip_non_whitespace(str))[1] = '\0';
-               return xstrdup(str);
-       }
-       return NULL;
-}
-
 /* display header info (meminfo / loadavg) */
-static void display_topmem_header(int scr_width)
+static void display_topmem_header(int scr_width, int *lines_rem_p)
 {
-       char linebuf[128];
-       int i;
-       FILE *fp;
-       union {
-               struct {
-                       /*  1 */ char *total;
-                       /*  2 */ char *mfree;
-                       /*  3 */ char *buf;
-                       /*  4 */ char *cache;
-                       /*  5 */ char *swaptotal;
-                       /*  6 */ char *swapfree;
-                       /*  7 */ char *dirty;
-                       /*  8 */ char *mwrite;
-                       /*  9 */ char *anon;
-                       /* 10 */ char *map;
-                       /* 11 */ char *slab;
-               } u;
-               char *str[11];
-       } Z;
-#define total     Z.u.total
-#define mfree     Z.u.mfree
-#define buf       Z.u.buf
-#define cache     Z.u.cache
-#define swaptotal Z.u.swaptotal
-#define swapfree  Z.u.swapfree
-#define dirty     Z.u.dirty
-#define mwrite    Z.u.mwrite
-#define anon      Z.u.anon
-#define map       Z.u.map
-#define slab      Z.u.slab
-#define str       Z.str
-
-       memset(&Z, 0, sizeof(Z));
+       enum {
+               TOTAL = 0, MFREE, BUF, CACHE,
+               SWAPTOTAL, SWAPFREE, DIRTY,
+               MWRITE, ANON, MAP, SLAB,
+               NUM_FIELDS
+       };
+       static const char match[NUM_FIELDS][12] = {
+               "\x09" "MemTotal:",  // TOTAL
+               "\x08" "MemFree:",   // MFREE
+               "\x08" "Buffers:",   // BUF
+               "\x07" "Cached:",    // CACHE
+               "\x0a" "SwapTotal:", // SWAPTOTAL
+               "\x09" "SwapFree:",  // SWAPFREE
+               "\x06" "Dirty:",     // DIRTY
+               "\x0a" "Writeback:", // MWRITE
+               "\x0a" "AnonPages:", // ANON
+               "\x07" "Mapped:",    // MAP
+               "\x05" "Slab:",      // SLAB
+       };
+       char meminfo_buf[4 * 1024];
+       const char *Z[NUM_FIELDS];
+       unsigned i;
+       int sz;
+
+       for (i = 0; i < NUM_FIELDS; i++)
+               Z[i] = "?";
 
        /* read memory info */
-       fp = xfopen("meminfo", "r");
-       while (fgets(linebuf, sizeof(linebuf), fp)) {
-               char *p;
-
-#define SCAN(match, name) \
-               p = grab_number(linebuf, match, sizeof(match)-1); \
-               if (p) { name = p; continue; }
-
-               SCAN("MemTotal:", total);
-               SCAN("MemFree:", mfree);
-               SCAN("Buffers:", buf);
-               SCAN("Cached:", cache);
-               SCAN("SwapTotal:", swaptotal);
-               SCAN("SwapFree:", swapfree);
-               SCAN("Dirty:", dirty);
-               SCAN("Writeback:", mwrite);
-               SCAN("AnonPages:", anon);
-               SCAN("Mapped:", map);
-               SCAN("Slab:", slab);
-#undef SCAN
+       sz = open_read_close("meminfo", meminfo_buf, sizeof(meminfo_buf) - 1);
+       if (sz >= 0) {
+               char *p = meminfo_buf;
+               meminfo_buf[sz] = '\0';
+               /* Note that fields always appear in the match[] order */
+               for (i = 0; i < NUM_FIELDS; i++) {
+                       char *found = strstr(p, match[i] + 1);
+                       if (found) {
+                               /* Cut "NNNN" out of "    NNNN kb" */
+                               char *s = skip_whitespace(found + match[i][0]);
+                               p = skip_non_whitespace(s);
+                               *p++ = '\0';
+                               Z[i] = s;
+                       }
+               }
        }
-       fclose(fp);
 
-#define S(s) (s ? s : "0 ")
-       snprintf(linebuf, sizeof(linebuf),
-               "Mem %stotal %sanon %smap %sfree",
-               S(total), S(anon), S(map), S(mfree));
-       printf(OPT_BATCH_MODE ? "%.*s\n" : "\e[H\e[J%.*s\n", scr_width, linebuf);
-
-       snprintf(linebuf, sizeof(linebuf),
-               " %sslab %sbuf %scache %sdirty %swrite",
-               S(slab), S(buf), S(cache), S(dirty), S(mwrite));
-       printf("%.*s\n", scr_width, linebuf);
-
-       snprintf(linebuf, sizeof(linebuf),
-               "Swap %stotal %sfree", // TODO: % used?
-               S(swaptotal), S(swapfree));
-       printf("%.*s\n", scr_width, linebuf);
-#undef S
-
-       for (i = 0; i < ARRAY_SIZE(str); i++)
-               free(str[i]);
-#undef total
-#undef free
-#undef buf
-#undef cache
-#undef swaptotal
-#undef swapfree
-#undef dirty
-#undef write
-#undef anon
-#undef map
-#undef slab
-#undef str
+       snprintf(line_buf, LINE_BUF_SIZE,
+               "Mem total:%s anon:%s map:%s free:%s",
+               Z[TOTAL], Z[ANON], Z[MAP], Z[MFREE]);
+       printf(OPT_BATCH_MODE ? "%.*s\n" : "\033[H\033[J%.*s\n", scr_width, line_buf);
+
+       snprintf(line_buf, LINE_BUF_SIZE,
+               " slab:%s buf:%s cache:%s dirty:%s write:%s",
+               Z[SLAB], Z[BUF], Z[CACHE], Z[DIRTY], Z[MWRITE]);
+       printf("%.*s\n", scr_width, line_buf);
+
+       snprintf(line_buf, LINE_BUF_SIZE,
+               "Swap total:%s free:%s", // TODO: % used?
+               Z[SWAPTOTAL], Z[SWAPFREE]);
+       printf("%.*s\n", scr_width, line_buf);
+
+       (*lines_rem_p) -= 3;
 }
 
 static void ulltoa6_and_space(unsigned long long ul, char buf[6])
 {
        /* see http://en.wikipedia.org/wiki/Tera */
-       smart_ulltoa5(ul, buf, " mgtpezy");
-       buf[5] = ' ';
+       smart_ulltoa5(ul, buf, " mgtpezy")[0] = ' ';
 }
 
-static NOINLINE void display_topmem_process_list(int count, int scr_width)
+static NOINLINE void display_topmem_process_list(int lines_rem, int scr_width)
 {
 #define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
 #define MIN_WIDTH sizeof(HDR_STR)
-       const topmem_status_t *s = topmem;
+       const topmem_status_t *s = topmem + G_scroll_ofs;
 
-       display_topmem_header(scr_width);
+       display_topmem_header(scr_width, &lines_rem);
        strcpy(line_buf, HDR_STR " COMMAND");
-       line_buf[5 + sort_field * 6] = '*';
+       line_buf[11 + sort_field * 6] = "^_"[inverted];
        printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width, line_buf);
+       lines_rem--;
 
-       while (--count >= 0) {
-               // PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND
+       if (lines_rem > ntop - G_scroll_ofs)
+               lines_rem = ntop - G_scroll_ofs;
+       while (--lines_rem >= 0) {
+               /* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
                ulltoa6_and_space(s->pid     , &line_buf[0*6]);
                ulltoa6_and_space(s->vsz     , &line_buf[1*6]);
                ulltoa6_and_space(s->vszrw   , &line_buf[2*6]);
@@ -703,19 +875,20 @@ static NOINLINE void display_topmem_process_list(int count, int scr_width)
                ulltoa6_and_space(s->dirty_sh, &line_buf[6*6]);
                ulltoa6_and_space(s->stack   , &line_buf[7*6]);
                line_buf[8*6] = '\0';
-               if (scr_width > MIN_WIDTH) {
+               if (scr_width > (int)MIN_WIDTH) {
                        read_cmdline(&line_buf[8*6], scr_width - MIN_WIDTH, s->pid, s->comm);
                }
                printf("\n""%.*s", scr_width, line_buf);
                s++;
        }
        bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
-       fflush(stdout);
+       fflush_all();
 #undef HDR_STR
 #undef MIN_WIDTH
 }
+
 #else
-void display_topmem_process_list(int count, int scr_width);
+void display_topmem_process_list(int lines_rem, int scr_width);
 int topmem_sort(char *a, char *b);
 #endif /* TOPMEM */
 
@@ -732,54 +905,252 @@ enum {
                | PSSCAN_UTIME
                | PSSCAN_STATE
                | PSSCAN_COMM
+               | PSSCAN_CPU
                | PSSCAN_UIDGID,
        TOPMEM_MASK = 0
                | PSSCAN_PID
                | PSSCAN_SMAPS
                | PSSCAN_COMM,
+       EXIT_MASK = (unsigned)-1,
 };
 
-int top_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int top_main(int argc ATTRIBUTE_UNUSED, char **argv)
-{
-       int count, lines, col;
-       unsigned interval;
-       int iterations;
-       char *sinterval;
-       SKIP_FEATURE_TOPMEM(const) unsigned scan_mask = TOP_MASK;
 #if ENABLE_FEATURE_USE_TERMIOS
-       struct termios new_settings;
+static unsigned handle_input(unsigned scan_mask, unsigned interval)
+{
        struct pollfd pfd[1];
-       unsigned char c;
+
+       if (option_mask32 & OPT_EOF) {
+               /* EOF on stdin ("top </dev/null") */
+               sleep(interval);
+               return scan_mask;
+       }
 
        pfd[0].fd = 0;
        pfd[0].events = POLLIN;
-#endif /* FEATURE_USE_TERMIOS */
+
+       while (1) {
+               int32_t c;
+
+               c = read_key(STDIN_FILENO, G.kbd_input, interval * 1000);
+               if (c == -1 && errno != EAGAIN) {
+                       /* error/EOF */
+                       option_mask32 |= OPT_EOF;
+                       break;
+               }
+               interval = 0;
+
+               if (c == initial_settings.c_cc[VINTR])
+                       return EXIT_MASK;
+               if (c == initial_settings.c_cc[VEOF])
+                       return EXIT_MASK;
+
+               if (c == KEYCODE_UP) {
+                       G_scroll_ofs--;
+                       goto normalize_ofs;
+               }
+               if (c == KEYCODE_DOWN) {
+                       G_scroll_ofs++;
+                       goto normalize_ofs;
+               }
+               if (c == KEYCODE_HOME) {
+                       G_scroll_ofs = 0;
+                       break;
+               }
+               if (c == KEYCODE_END) {
+                       G_scroll_ofs = ntop - G.lines / 2;
+                       goto normalize_ofs;
+               }
+               if (c == KEYCODE_PAGEUP) {
+                       G_scroll_ofs -= G.lines / 2;
+                       goto normalize_ofs;
+               }
+               if (c == KEYCODE_PAGEDOWN) {
+                       G_scroll_ofs += G.lines / 2;
+ normalize_ofs:
+                       if (G_scroll_ofs >= ntop)
+                               G_scroll_ofs = ntop - 1;
+                       if (G_scroll_ofs < 0)
+                               G_scroll_ofs = 0;
+                       break;
+               }
+
+               c |= 0x20; /* lowercase */
+               if (c == 'q')
+                       return EXIT_MASK;
+
+               if (c == 'n') {
+                       IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
+                       sort_function[0] = pid_sort;
+                       continue;
+               }
+               if (c == 'm') {
+                       IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
+                       sort_function[0] = mem_sort;
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+                       sort_function[1] = pcpu_sort;
+                       sort_function[2] = time_sort;
+# endif
+                       continue;
+               }
+# if ENABLE_FEATURE_SHOW_THREADS
+               if (c == 'h'
+               IF_FEATURE_TOPMEM(&& scan_mask != TOPMEM_MASK)
+               ) {
+                       scan_mask ^= PSSCAN_TASKS;
+                       continue;
+               }
+# endif
+# if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
+               if (c == 'p') {
+                       IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
+                       sort_function[0] = pcpu_sort;
+                       sort_function[1] = mem_sort;
+                       sort_function[2] = time_sort;
+                       continue;
+               }
+               if (c == 't') {
+                       IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
+                       sort_function[0] = time_sort;
+                       sort_function[1] = mem_sort;
+                       sort_function[2] = pcpu_sort;
+                       continue;
+               }
+#  if ENABLE_FEATURE_TOPMEM
+               if (c == 's') {
+                       scan_mask = TOPMEM_MASK;
+                       free(prev_hist);
+                       prev_hist = NULL;
+                       prev_hist_count = 0;
+                       sort_field = (sort_field + 1) % NUM_SORT_FIELD;
+                       continue;
+               }
+#  endif
+               if (c == 'r') {
+                       inverted ^= 1;
+                       continue;
+               }
+#  if ENABLE_FEATURE_TOP_SMP_CPU
+               /* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
+               if (c == 'c' || c == '1') {
+                       /* User wants to toggle per cpu <> aggregate */
+                       if (smp_cpu_info) {
+                               free(cpu_prev_jif);
+                               free(cpu_jif);
+                               cpu_jif = &cur_jif;
+                               cpu_prev_jif = &prev_jif;
+                       } else {
+                               /* Prepare for xrealloc() */
+                               cpu_jif = cpu_prev_jif = NULL;
+                       }
+                       num_cpus = 0;
+                       smp_cpu_info = !smp_cpu_info;
+                       get_jiffy_counts();
+                       continue;
+               }
+#  endif
+# endif
+               break; /* unknown key -> force refresh */
+       }
+
+       return scan_mask;
+}
+#endif
+
+//usage:#if ENABLE_FEATURE_SHOW_THREADS || ENABLE_FEATURE_TOP_SMP_CPU
+//usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...) __VA_ARGS__
+//usage:#else
+//usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...)
+//usage:#endif
+//usage:#define top_trivial_usage
+//usage:       "[-b] [-nCOUNT] [-dSECONDS]" IF_FEATURE_TOPMEM(" [-m]")
+//usage:#define top_full_usage "\n\n"
+//usage:       "Provide a view of process activity in real time."
+//usage:   "\n""Read the status of all processes from /proc each SECONDS"
+//usage:   "\n""and display a screenful of them."
+//usage:   "\n""Keys:"
+//usage:   "\n""       N/M"
+//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/P")
+//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/T")
+//usage:           ": " IF_FEATURE_TOPMEM("show CPU usage, ") "sort by pid/mem"
+//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/cpu")
+//usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/time")
+//usage:       IF_FEATURE_TOPMEM(
+//usage:   "\n""       S: show memory"
+//usage:       )
+//usage:   "\n""       R: reverse sort"
+//usage:       IF_SHOW_THREADS_OR_TOP_SMP(
+//usage:   "\n""       "
+//usage:                IF_FEATURE_SHOW_THREADS("H: toggle threads")
+//usage:                IF_FEATURE_SHOW_THREADS(IF_FEATURE_TOP_SMP_CPU(", "))
+//usage:                IF_FEATURE_TOP_SMP_CPU("1: toggle SMP")
+//usage:       )
+//usage:   "\n""       Q,^C: exit"
+//usage:   "\n"
+//usage:   "\n""Options:"
+//usage:   "\n""       -b      Batch mode"
+//usage:   "\n""       -n N    Exit after N iterations"
+//usage:   "\n""       -d N    Delay between updates"
+//usage:       IF_FEATURE_TOPMEM(
+//usage:   "\n""       -m      Same as 's' key"
+//usage:       )
+
+/* Interactive testing:
+ * echo sss | ./busybox top
+ * - shows memory screen
+ * echo sss | ./busybox top -bn1 >mem
+ * - saves memory screen - the *whole* list, not first NROWS processes!
+ * echo .m.s.s.s.s.s.s.q | ./busybox top -b >z
+ * - saves several different screens, and exits
+ *
+ * TODO: -i STRING param as a better alternative?
+ */
+
+int top_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int top_main(int argc UNUSED_PARAM, char **argv)
+{
+       int iterations;
+       unsigned col;
+       unsigned interval;
+       char *str_interval, *str_iterations;
+       unsigned scan_mask = TOP_MASK;
+#if ENABLE_FEATURE_USE_TERMIOS
+       struct termios new_settings;
+#endif
 
        INIT_G();
 
        interval = 5; /* default update interval is 5 seconds */
        iterations = 0; /* infinite */
+#if ENABLE_FEATURE_TOP_SMP_CPU
+       /*num_cpus = 0;*/
+       /*smp_cpu_info = 0;*/  /* to start with show aggregate */
+       cpu_jif = &cur_jif;
+       cpu_prev_jif = &prev_jif;
+#endif
 
        /* all args are options; -n NUM */
-       opt_complementary = "-:n+";
-       getopt32(argv, "d:n:b", &sinterval, &iterations);
-       if (option_mask32 & OPT_d) {
+       opt_complementary = "-"; /* options can be specified w/o dash */
+       col = getopt32(argv, "d:n:b"IF_FEATURE_TOPMEM("m"), &str_interval, &str_iterations);
+#if ENABLE_FEATURE_TOPMEM
+       if (col & OPT_m) /* -m (busybox specific) */
+               scan_mask = TOPMEM_MASK;
+#endif
+       if (col & OPT_d) {
+               /* work around for "-d 1" -> "-d -1" done by getopt32
+                * (opt_complementary == "-" does this) */
+               if (str_interval[0] == '-')
+                       str_interval++;
                /* Need to limit it to not overflow poll timeout */
-               interval = xatou16(sinterval); // -d
+               interval = xatou16(str_interval);
+       }
+       if (col & OPT_n) {
+               if (str_iterations[0] == '-')
+                       str_iterations++;
+               iterations = xatou(str_iterations);
        }
 
        /* change to /proc */
        xchdir("/proc");
-#if ENABLE_FEATURE_USE_TERMIOS
-       tcgetattr(0, (void *) &initial_settings);
-       memcpy(&new_settings, &initial_settings, sizeof(new_settings));
-       /* unbuffered input, turn off echo */
-       new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
-
-       bb_signals(BB_FATAL_SIGS, sig_catcher);
-       tcsetattr(0, TCSANOW, (void *) &new_settings);
-#endif /* FEATURE_USE_TERMIOS */
 
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
        sort_function[0] = pcpu_sort;
@@ -787,34 +1158,57 @@ int top_main(int argc ATTRIBUTE_UNUSED, char **argv)
        sort_function[2] = time_sort;
 #else
        sort_function[0] = mem_sort;
-#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
+#endif
 
-       while (1) {
+       if (OPT_BATCH_MODE) {
+               option_mask32 |= OPT_EOF;
+       }
+#if ENABLE_FEATURE_USE_TERMIOS
+       else {
+               tcgetattr(0, (void *) &initial_settings);
+               memcpy(&new_settings, &initial_settings, sizeof(new_settings));
+               /* unbuffered input, turn off echo */
+               new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
+               tcsetattr_stdin_TCSANOW(&new_settings);
+       }
+
+       bb_signals(BB_FATAL_SIGS, sig_catcher);
+
+       /* Eat initial input, if any */
+       scan_mask = handle_input(scan_mask, 0);
+#endif
+
+       while (scan_mask != EXIT_MASK) {
                procps_status_t *p = NULL;
 
-               lines = 24; /* default */
-               col = 79;
+               if (OPT_BATCH_MODE) {
+                       G.lines = INT_MAX;
+                       col = LINE_BUF_SIZE - 2; /* +2 bytes for '\n', NUL */
+               } else {
+                       G.lines = 24; /* default */
+                       col = 79;
 #if ENABLE_FEATURE_USE_TERMIOS
-               /* We output to stdout, we need size of stdout (not stdin)! */
-               get_terminal_width_height(STDOUT_FILENO, &col, &lines);
-               if (lines < 5 || col < 10) {
-                       sleep(interval);
-                       continue;
+                       /* We output to stdout, we need size of stdout (not stdin)! */
+                       get_terminal_width_height(STDOUT_FILENO, &col, &G.lines);
+                       if (G.lines < 5 || col < 10) {
+                               sleep(interval);
+                               continue;
+                       }
+#endif
+                       if (col > LINE_BUF_SIZE - 2)
+                               col = LINE_BUF_SIZE - 2;
                }
-#endif /* FEATURE_USE_TERMIOS */
-               if (col > LINE_BUF_SIZE-2) /* +2 bytes for '\n', NUL, */
-                       col = LINE_BUF_SIZE-2;
-               if (!ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && scan_mask == TOP_MASK)
-                       lines -= 3;
-               else
-                       lines -= 4;
 
                /* read process IDs & status for all the processes */
+               ntop = 0;
                while ((p = procps_scan(p, scan_mask)) != NULL) {
                        int n;
-                       if (scan_mask == TOP_MASK) {
+#if ENABLE_FEATURE_TOPMEM
+                       if (scan_mask != TOPMEM_MASK)
+#endif
+                       {
                                n = ntop;
-                               top = xrealloc(top, (++ntop) * sizeof(*top));
+                               top = xrealloc_vector(top, 6, ntop++);
                                top[n].pid = p->pid;
                                top[n].ppid = p->ppid;
                                top[n].vsz = p->vsz;
@@ -824,30 +1218,35 @@ int top_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                top[n].uid = p->uid;
                                strcpy(top[n].state, p->state);
                                strcpy(top[n].comm, p->comm);
-                       } else { /* TOPMEM */
+#if ENABLE_FEATURE_TOP_SMP_PROCESS
+                               top[n].last_seen_on_cpu = p->last_seen_on_cpu;
+#endif
+                       }
 #if ENABLE_FEATURE_TOPMEM
-                               if (!(p->mapped_ro | p->mapped_rw))
+                       else { /* TOPMEM */
+                               if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
                                        continue; /* kernel threads are ignored */
                                n = ntop;
-                               top = xrealloc(topmem, (++ntop) * sizeof(*topmem));
+                               /* No bug here - top and topmem are the same */
+                               top = xrealloc_vector(topmem, 6, ntop++);
                                strcpy(topmem[n].comm, p->comm);
                                topmem[n].pid      = p->pid;
-                               topmem[n].vsz      = p->mapped_rw + p->mapped_ro;
-                               topmem[n].vszrw    = p->mapped_rw;
-                               topmem[n].rss_sh   = p->shared_clean + p->shared_dirty;
-                               topmem[n].rss      = p->private_clean + p->private_dirty + topmem[n].rss_sh;
-                               topmem[n].dirty    = p->private_dirty + p->shared_dirty;
-                               topmem[n].dirty_sh = p->shared_dirty;
-                               topmem[n].stack    = p->stack;
-#endif
+                               topmem[n].vsz      = p->smaps.mapped_rw + p->smaps.mapped_ro;
+                               topmem[n].vszrw    = p->smaps.mapped_rw;
+                               topmem[n].rss_sh   = p->smaps.shared_clean + p->smaps.shared_dirty;
+                               topmem[n].rss      = p->smaps.private_clean + p->smaps.private_dirty + topmem[n].rss_sh;
+                               topmem[n].dirty    = p->smaps.private_dirty + p->smaps.shared_dirty;
+                               topmem[n].dirty_sh = p->smaps.shared_dirty;
+                               topmem[n].stack    = p->smaps.stack;
                        }
+#endif
                } /* end of "while we read /proc" */
                if (ntop == 0) {
                        bb_error_msg("no process info in /proc");
                        break;
                }
 
-               if (scan_mask == TOP_MASK) {
+               if (scan_mask != TOPMEM_MASK) {
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
                        if (!prev_hist_count) {
                                do_stats();
@@ -856,26 +1255,22 @@ int top_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                continue;
                        }
                        do_stats();
-/* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
+                       /* 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[0]));
-#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
+#endif
                }
 #if ENABLE_FEATURE_TOPMEM
                else { /* TOPMEM */
                        qsort(topmem, ntop, sizeof(topmem_status_t), (void*)topmem_sort);
                }
 #endif
-               count = lines;
-               if (OPT_BATCH_MODE || count > ntop) {
-                       count = ntop;
-               }
-               if (scan_mask == TOP_MASK)
-                       display_process_list(count, col);
+               if (scan_mask != TOPMEM_MASK)
+                       display_process_list(G.lines, col);
 #if ENABLE_FEATURE_TOPMEM
                else
-                       display_topmem_process_list(count, col);
+                       display_topmem_process_list(G.lines, col);
 #endif
                clearmems();
                if (iterations >= 0 && !--iterations)
@@ -883,59 +1278,9 @@ int top_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #if !ENABLE_FEATURE_USE_TERMIOS
                sleep(interval);
 #else
-               if (option_mask32 & (OPT_b|OPT_EOF))
-                        /* batch mode, or EOF on stdin ("top </dev/null") */
-                       sleep(interval);
-               else if (safe_poll(pfd, 1, interval * 1000) > 0) {
-                       if (safe_read(0, &c, 1) != 1) { /* error/EOF? */
-                               option_mask32 |= OPT_EOF;
-                               continue;
-                       }
-                       if (c == initial_settings.c_cc[VINTR])
-                               break;
-                       c |= 0x20; /* lowercase */
-                       if (c == 'q')
-                               break;
-                       if (c == 'n') {
-                               USE_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
-                               sort_function[0] = pid_sort;
-                       }
-                       if (c == 'm') {
-                               USE_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
-                               sort_function[0] = mem_sort;
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
-                               sort_function[1] = pcpu_sort;
-                               sort_function[2] = time_sort;
-#endif
-                       }
-#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
-                       if (c == 'p') {
-                               USE_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
-                               sort_function[0] = pcpu_sort;
-                               sort_function[1] = mem_sort;
-                               sort_function[2] = time_sort;
-                       }
-                       if (c == 't') {
-                               USE_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
-                               sort_function[0] = time_sort;
-                               sort_function[1] = mem_sort;
-                               sort_function[2] = pcpu_sort;
-                       }
-#if ENABLE_FEATURE_TOPMEM
-                       if (c == 's') {
-                               scan_mask = TOPMEM_MASK;
-                               free(prev_hist);
-                               prev_hist = NULL;
-                               prev_hist_count = 0;
-                               sort_field = (sort_field + 1) % NUM_SORT_FIELD;
-                       }
-                       if (c == 'r')
-                               inverted ^= 1;
-#endif
-#endif
-               }
+               scan_mask = handle_input(scan_mask, interval);
 #endif /* FEATURE_USE_TERMIOS */
-       } /* end of "while (1)" */
+       } /* end of "while (not Q)" */
 
        bb_putchar('\n');
 #if ENABLE_FEATURE_USE_TERMIOS