2 files changed, 314 insertions, 163 deletions

diff --git a/procps/pmap.c b/procps/pmap.c
index 49f7688d9..3069856a4 100644
--- a/procps/pmap.c
+++ b/procps/pmap.c
@@ -29,10 +29,14 @@
 
 #if ULLONG_MAX == 0xffffffff
 # define TABS "\t"
+# define SIZEWIDTHx "7"
+# define SIZEWIDTH  "9"
 # define AFMTLL "8"
 # define DASHES ""
 #else
 # define TABS "\t\t"
+# define SIZEWIDTHx "15"
+# define SIZEWIDTH  "17"
 # define AFMTLL "16"
 # define DASHES "--------"
 #endif
@@ -42,49 +46,145 @@ enum {
         OPT_q = 1 << 1,
 };
 
-static void print_smaprec(struct smaprec *currec, void *data)
-{
-        unsigned opt = (uintptr_t)data;
+struct smaprec {
+        // For mixed 32/64 userspace, 32-bit pmap still needs
+        // 64-bit field here to correctly show 64-bit processes:
+        unsigned long long smap_start;
+        // Make size wider too:
+        // I've seen 1203765248 kb large "---p" mapping in a browser,
+        // this cuts close to 4 terabytes.
+        unsigned long long smap_size;
+        // (strictly speaking, other fields need to be wider too,
+        // but they are in kbytes, not bytes, and they hold sizes,
+        // not start addresses, sizes tend to be less than 4 terabytes)
+        unsigned long private_dirty;
+        unsigned long smap_pss, smap_swap;
+        char smap_mode[5];
+        char *smap_name;
+};
 
+// How long the filenames and command lines we want to handle?
+#define PMAP_BUFSZ 4096
+
+static void print_smaprec(struct smaprec *currec)
+{
         printf("%0" AFMTLL "llx ", currec->smap_start);
 
-        if (opt & OPT_x)
-                printf("%7lu %7lu %7lu %7lu ",
+        if (option_mask32 & OPT_x)
+                printf("%7llu %7lu %7lu %7lu ",
                         currec->smap_size,
                         currec->smap_pss,
                         currec->private_dirty,
                         currec->smap_swap);
         else
-                printf("%7luK", currec->smap_size);
+                printf("%7lluK", currec->smap_size);
 
-        printf(" %.4s  %s\n", currec->smap_mode, currec->smap_name);
+        printf(" %.4s  %s\n", currec->smap_mode, currec->smap_name ? : "  [ anon ]");
+}
+
+/* libbb's procps_read_smaps() looks somewhat similar,
+ * but the collected information is sufficiently different
+ * that merging them into one function is not a good idea
+ * (unless you feel masochistic today).
+ */
+static int read_smaps(pid_t pid, char buf[PMAP_BUFSZ], struct smaprec *total)
+{
+        FILE *file;
+        struct smaprec currec;
+        char filename[sizeof("/proc/%u/smaps") + sizeof(int)*3];
+
+        sprintf(filename, "/proc/%u/smaps", (int)pid);
+
+        file = fopen_for_read(filename);
+        if (!file)
+                return 1;
+
+        memset(&currec, 0, sizeof(currec));
+        while (fgets(buf, PMAP_BUFSZ, file)) {
+                // Each mapping datum has this form:
+                // f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
+                // Size:                nnn kB
+                // Rss:                 nnn kB
+                // .....
+
+                char *tp, *p;
+
+                if (buf[0] == 'S' || buf[0] == 'P') {
+#define SCAN(S, X) \
+                        if (memcmp(buf, S, sizeof(S)-1) == 0) { \
+                                tp = skip_whitespace(buf + sizeof(S)-1); \
+                                total->X += currec.X = fast_strtoul_10(&tp); \
+                                continue; \
+                        }
+                        SCAN("Pss:"          , smap_pss     );
+                        SCAN("Swap:"         , smap_swap    );
+                        SCAN("Private_Dirty:", private_dirty);
+#undef SCAN
+                }
+                tp = strchr(buf, '-');
+                if (tp) {
+                        // We reached next mapping - the line of this form:
+                        // f7d29000-f7d39000 rw-s FILEOFS M:m INODE FILENAME
+
+                        // If we have a previous record, there's nothing more
+                        // for it, print and clear currec
+                        if (currec.smap_size)
+                                print_smaprec(&currec);
+                        free(currec.smap_name);
+                        memset(&currec, 0, sizeof(currec));
+
+                        *tp = ' ';
+                        tp = buf;
+                        currec.smap_start = fast_strtoull_16(&tp);
+                        currec.smap_size = (fast_strtoull_16(&tp) - currec.smap_start) >> 10;
+                        strncpy(currec.smap_mode, tp, sizeof(currec.smap_mode)-1);
+
+                        // skipping "rw-s FILEOFS M:m INODE "
+                        tp = skip_fields(tp, 4);
+                        tp = skip_whitespace(tp); // there may be many spaces, can't just "tp++"
+                        p = strchrnul(tp, '\n');
+                        if (p != tp) {
+                                currec.smap_name = xstrndup(tp, p - tp);
+                        }
+                        total->smap_size += currec.smap_size;
+                }
+        } // while (got line)
+        fclose(file);
+
+        if (currec.smap_size)
+                print_smaprec(&currec);
+        free(currec.smap_name);
+
+        return 0;
 }
 
 static int procps_get_maps(pid_t pid, unsigned opt)
 {
         struct smaprec total;
         int ret;
-        char buf[256];
+        char buf[PMAP_BUFSZ];
+
+        ret = read_cmdline(buf, sizeof(buf), pid, NULL);
+        if (ret < 0)
+                return ret;
 
-        read_cmdline(buf, sizeof(buf), pid, NULL);
         printf("%u: %s\n", (int)pid, buf);
 
         if (!(opt & OPT_q) && (opt & OPT_x))
                 puts("Address" TABS "  Kbytes     PSS   Dirty    Swap  Mode  Mapping");
 
         memset(&total, 0, sizeof(total));
-
-        ret = procps_read_smaps(pid, &total, print_smaprec, (void*)(uintptr_t)opt);
+        ret = read_smaps(pid, buf, &total);
         if (ret)
                 return ret;
 
         if (!(opt & OPT_q)) {
                 if (opt & OPT_x)
                         printf("--------" DASHES "  ------  ------  ------  ------\n"
-                                "total" TABS " %7lu %7lu %7lu %7lu\n",
+                                "total kB %"SIZEWIDTHx"llu %7lu %7lu %7lu\n",
                                 total.smap_size, total.smap_pss, total.private_dirty, total.smap_swap);
                 else
-                        printf("mapped: %luK\n", total.smap_size);
+                        printf(" total %"SIZEWIDTH"lluK\n", total.smap_size);
         }
 
         return 0;
diff --git a/procps/top.c b/procps/top.c
index 09d31c673..96b3e2d4e 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -117,10 +117,15 @@
 
 #include "libbb.h"
 
-#define ESC "\033"
+#define ESC     "\033"
+#define HOME    ESC"[H"
+#define CLREOS  ESC"[J"
+#define CLREOL  ESC"[K"
+#define REVERSE ESC"[7m"
+#define NORMAL  ESC"[m"
 
 typedef struct top_status_t {
-        unsigned long vsz;
+        unsigned long memsize;
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
         unsigned long ticks;
         unsigned pcpu; /* delta of ticks */
@@ -161,13 +166,16 @@ struct globals {
         top_status_t *top;
         int ntop;
         smallint inverted;
+        smallint not_first_line;
 #if ENABLE_FEATURE_TOPMEM
         smallint sort_field;
 #endif
 #if ENABLE_FEATURE_TOP_SMP_CPU
         smallint smp_cpu_info; /* one/many cpu info lines? */
 #endif
-        unsigned lines;  /* screen height */
+        int lines_remaining;
+        unsigned lines;     /* screen height */
+        unsigned scr_width; /* width, clamped <= LINE_BUF_SIZE-2 */
 #if ENABLE_FEATURE_TOP_INTERACTIVE
         struct termios initial_settings;
         int scroll_ofs;
@@ -212,7 +220,6 @@ struct globals {
 #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 { \
         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
         BUILD_BUG_ON(LINE_BUF_SIZE <= 80); \
@@ -241,8 +248,8 @@ static int pid_sort(top_status_t *P, top_status_t *Q)
 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 (Q->memsize < P->memsize) return -1;
+        return Q->memsize != P->memsize; /* 0 if ==, 1 if > */
 }
 
 
@@ -283,9 +290,9 @@ static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
 #endif
         int ret;
 
-        if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
+        if (!fgets(G.line_buf, LINE_BUF_SIZE, fp) || G.line_buf[0] != 'c' /* not "cpu" */)
                 return 0;
-        ret = sscanf(line_buf, fmt,
+        ret = sscanf(G.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);
@@ -362,7 +369,7 @@ static void do_stats(void)
 
         get_jiffy_counts();
         total_pcpu = 0;
-        /* total_vsz = 0; */
+        /* total_memsize = 0; */
         new_hist = xmalloc(sizeof(new_hist[0]) * ntop);
         /*
          * Make a pass through the data to get stats.
@@ -394,7 +401,7 @@ static void do_stats(void)
                         i = (i+1) % prev_hist_count;
                         /* hist_iterations++; */
                 } while (i != last_i);
-                /* total_vsz += cur->vsz; */
+                /* total_memsize += cur->memsize; */
         }
 
         /*
@@ -407,6 +414,38 @@ static void do_stats(void)
 
 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 
+static void print_line_buf(void)
+{
+        const char *fmt;
+
+        G.lines_remaining--;
+        fmt = OPT_BATCH_MODE ? "\n""%.*s" : "\n""%.*s"CLREOL;
+        if (!G.not_first_line) {
+                G.not_first_line = 1;
+                /* Go to top */
+                fmt = OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL;
+        }
+        printf(fmt, G.scr_width - 1, G.line_buf);
+}
+
+static void print_line_bold(void)
+{
+        G.lines_remaining--;
+//we never print first line in bold
+//      if (!G.not_first_line) {
+//              printf(OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL, G.scr_width - 1, G.line_buf);
+//              G.not_first_line = 1;
+//      } else {
+                printf(OPT_BATCH_MODE ? "\n""%.*s" : "\n"REVERSE"%.*s"NORMAL CLREOL, G.scr_width - 1, G.line_buf);
+//      }
+}
+
+static void print_end(void)
+{
+        fputs_stdout(OPT_BATCH_MODE ? "\n" : CLREOS"\r");
+        G.not_first_line = 0; /* next print will be "first line" (will clear the screen) */
+}
+
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
 /* formats 7 char string (8 with terminating NUL) */
 static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
@@ -433,7 +472,7 @@ static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
 #endif
 
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
-static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
+static void display_cpus(void)
 {
         /*
          * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
@@ -469,8 +508,8 @@ static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
 # 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;
+        if (n_cpu_lines > G.lines_remaining)
+                n_cpu_lines = G.lines_remaining;
 
         for (i = 0; i < n_cpu_lines; i++) {
                 p_jif = &cpu_jif[i];
@@ -488,7 +527,7 @@ static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
                         CALC_STAT(softirq);
                         /*CALC_STAT(steal);*/
 
-                        snprintf(scrbuf, scr_width,
+                        sprintf(G.line_buf,
                                 /* 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",
@@ -501,16 +540,15 @@ static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
                                 /*, SHOW_STAT(steal) - what is this 'steal' thing? */
                                 /* I doubt anyone wants to know it */
                         );
-                        puts(scrbuf);
+                        print_line_buf();
                 }
         }
 # 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)
+# define display_cpus() ((void)0)
 #endif
 
 enum {
@@ -564,52 +602,55 @@ static void parse_meminfo(unsigned long meminfo[MI_MAX])
         fclose(f);
 }
 
-static unsigned long display_header(int scr_width, int *lines_rem_p)
+static void cmdline_to_line_buf_and_print(unsigned offset, unsigned pid, const char *comm)
+{
+        int width = G.scr_width - offset;
+        if (width > 1) /* wider than to fit just the NUL? */
+                read_cmdline(G.line_buf + offset, width, pid, comm);
+//TODO: read_cmdline() sanitizes control chars, but not chars above 0x7e
+        print_line_buf();
+}
+
+static unsigned long display_header(void)
 {
-        char scrbuf[100]; /* [80] was a bit too low on 8Gb ram box */
         char *buf;
         unsigned long meminfo[MI_MAX];
 
         parse_meminfo(meminfo);
 
         /* Output memory info */
-        if (scr_width > (int)sizeof(scrbuf))
-                scr_width = sizeof(scrbuf);
-        snprintf(scrbuf, scr_width,
+        sprintf(G.line_buf,
                 "Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
                 meminfo[MI_MEMTOTAL] - meminfo[MI_MEMFREE],
                 meminfo[MI_MEMFREE],
                 meminfo[MI_MEMSHARED] + meminfo[MI_SHMEM],
                 meminfo[MI_BUFFERS],
                 meminfo[MI_CACHED]);
-        /* Go to top & clear to the end of screen */
-        printf(OPT_BATCH_MODE ? "%s\n" : ESC"[H" ESC"[J" "%s\n", scrbuf);
-        (*lines_rem_p)--;
+        print_line_buf();
 
         /* Display CPU time split as percentage of total time.
          * This displays either a cumulative line or one line per CPU.
          */
-        display_cpus(scr_width, scrbuf, lines_rem_p);
+        display_cpus();
 
         /* Read load average as a string */
-        buf = stpcpy(scrbuf, "Load average: ");
-        open_read_close("loadavg", buf, sizeof(scrbuf) - sizeof("Load average: "));
-        scrbuf[scr_width - 1] = '\0';
+        buf = stpcpy(G.line_buf, "Load average: ");
+        open_read_close("loadavg", buf, sizeof(G.line_buf) - sizeof("Load average: "));
+        G.line_buf[sizeof(G.line_buf) - 1] = '\0'; /* paranoia */
         strchrnul(buf, '\n')[0] = '\0';
-        puts(scrbuf);
-        (*lines_rem_p)--;
+        print_line_buf();
 
         return meminfo[MI_MEMTOTAL];
 }
 
-static NOINLINE void display_process_list(int lines_rem, int scr_width)
+static NOINLINE void display_process_list(void)
 {
         enum {
                 BITS_PER_INT = sizeof(int) * 8
         };
 
         top_status_t *s;
-        unsigned long total_memory = display_header(scr_width, &lines_rem); /* or use total_vsz? */
+        unsigned long total_memory = display_header();
         /* xxx_shift and xxx_scale variables allow us to replace
          * expensive divides with multiply and shift */
         unsigned pmem_shift, pmem_scale, pmem_half;
@@ -621,7 +662,7 @@ static NOINLINE void display_process_list(int lines_rem, int scr_width)
 
 #if ENABLE_FEATURE_TOP_DECIMALS
 # define UPSCALE 1000
-typedef struct { unsigned quot, rem; } bb_div_t;
+        typedef struct { unsigned quot, rem; } bb_div_t;
 /* Used to have "div_t name = div((val), 10)" here
  * (IOW: intended to use libc-compatible way to divide and use
  * both result and remainder, but musl does not inline div()...)
@@ -629,28 +670,34 @@ typedef struct { unsigned quot, rem; } bb_div_t;
  */
 # define CALC_STAT(name, val) bb_div_t name = { (val) / 10, (val) % 10 }
 # define SHOW_STAT(name) name.quot, '0'+name.rem
+# define SANITIZE(name)  if (name.quot > 99) name.quot = 99, name.rem = (unsigned char)('+' - '0')
 # define FMT "%3u.%c"
 #else
 # define UPSCALE 100
 # define CALC_STAT(name, val) unsigned name = (val)
+# define SANITIZE(name)  if (name > 99) name = 99
 # define SHOW_STAT(name) name
 # define FMT "%4u%%"
 #endif
 
-        /* what info of the processes is shown */
-        printf(OPT_BATCH_MODE ? "%.*s" : ESC"[7m" "%.*s" ESC"[m", scr_width,
-                "  PID  PPID USER     STAT   VSZ %VSZ"
+        strcpy(G.line_buf, "  PID  PPID USER     STAT   RSS %RSS"
                 IF_FEATURE_TOP_SMP_PROCESS(" CPU")
                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
                 " COMMAND");
-        lines_rem--;
-
-        /*
-         * %VSZ = s->vsz/MemTotal
+        print_line_bold();
+
+        /* %RSS = s->memsize / MemTotal * 100%
+         * Calculate this with multiply and shift. Example:
+         * shift = 12
+         * scale = 100 * 0x1000 / total_memory
+         * percent_mem = (size_mem * scale) >> shift
+         *            ~= (size_mem >> shift) * scale
+         *            ~= (size_mem >> shift) * 100 * (1 << shift) / total_memory
+         *            ~= size_mem * 100 / total_memory
          */
         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 */
+        /* s->memsize is in kb. we want (s->memsize * pmem_scale) to never overflow */
         while (pmem_scale >= 512) {
                 pmem_scale /= 4;
                 pmem_shift -= 2;
@@ -689,25 +736,29 @@ typedef struct { unsigned quot, rem; } bb_div_t;
         pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 #endif
+        if (G.lines_remaining > ntop - G_scroll_ofs)
+                G.lines_remaining = ntop - G_scroll_ofs;
 
         /* Ok, all preliminary data is ready, go through the list */
-        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) {
+        while (G.lines_remaining > 0) {
                 int n;
                 char *ppu;
                 char ppubuf[sizeof(int)*3 * 2 + 12];
-                char vsz_str_buf[8];
+                char memsize_str_buf[8];
                 unsigned col;
 
-                CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
+                CALC_STAT(pmem, (s->memsize*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
+                /* VSZ can be much larger than total memory
+                 * (seen values close to 2Tbyte), don't try to display
+                 * "uses 12345.6% of MemTotal" (won't fit the column)
+                 */
+                SANITIZE(pmem);
 
-                smart_ulltoa5(s->vsz, vsz_str_buf, " mgtpezy");
+                smart_ulltoa5(s->memsize, memsize_str_buf, " mgtpezy");
                 /* PID PPID USER STAT VSZ %VSZ [%CPU] COMMAND */
                 n = sprintf(ppubuf, "%5u %5u %-8.8s", s->pid, s->ppid, get_cached_username(s->uid));
                 ppu = ppubuf;
@@ -736,27 +787,23 @@ typedef struct { unsigned quot, rem; } bb_div_t;
                         ppu[6+6+8] = '\0'; /* truncate USER */
                 }
  shortened:
-                col = snprintf(line_buf, scr_width,
-                                "\n" "%s %s  %.5s" FMT
+                col = sprintf(G.line_buf,
+                                "%s %s  %.5s" FMT
                                 IF_FEATURE_TOP_SMP_PROCESS(" %3d")
                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
                                 " ",
                                 ppu,
-                                s->state, vsz_str_buf,
+                                s->state, memsize_str_buf,
                                 SHOW_STAT(pmem)
                                 IF_FEATURE_TOP_SMP_PROCESS(, s->last_seen_on_cpu)
                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
                 );
-                if ((int)(scr_width - col) > 1)
-                        read_cmdline(line_buf + col, scr_width - col, s->pid, s->comm);
-                fputs_stdout(line_buf);
+                cmdline_to_line_buf_and_print(col, s->pid, s->comm);
                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
                         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_all();
 }
 #undef UPSCALE
 #undef SHOW_STAT
@@ -828,36 +875,34 @@ static int topmem_sort(char *a, char *b)
 }
 
 /* display header info (meminfo / loadavg) */
-static void display_topmem_header(int scr_width, int *lines_rem_p)
+static void display_topmem_header(void)
 {
         unsigned long meminfo[MI_MAX];
 
         parse_meminfo(meminfo);
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 "Mem total:%lu anon:%lu map:%lu free:%lu",
                 meminfo[MI_MEMTOTAL],
                 meminfo[MI_ANONPAGES],
                 meminfo[MI_MAPPED],
                 meminfo[MI_MEMFREE]);
-        printf(OPT_BATCH_MODE ? "%.*s\n" : ESC"[H" ESC"[J" "%.*s\n", scr_width, line_buf);
+        print_line_buf();
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 " slab:%lu buf:%lu cache:%lu dirty:%lu write:%lu",
                 meminfo[MI_SLAB],
                 meminfo[MI_BUFFERS],
                 meminfo[MI_CACHED],
                 meminfo[MI_DIRTY],
                 meminfo[MI_WRITEBACK]);
-        printf("%.*s\n", scr_width, line_buf);
+        print_line_buf();
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 "Swap total:%lu free:%lu", // TODO: % used?
                 meminfo[MI_SWAPTOTAL],
                 meminfo[MI_SWAPFREE]);
-        printf("%.*s\n", scr_width, line_buf);
-
-        (*lines_rem_p) -= 3;
+        print_line_buf();
 }
 
 /* see http://en.wikipedia.org/wiki/Tera */
@@ -870,75 +915,57 @@ static void ulltoa4_and_space(unsigned long long ul, char buf[5])
         smart_ulltoa4(ul, buf, " mgtpezy")[0] = ' ';
 }
 
-static NOINLINE void display_topmem_process_list(int lines_rem, int scr_width)
+static NOINLINE void display_topmem_process_list(void)
 {
-#define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
-#define MIN_WIDTH sizeof(HDR_STR)
         const topmem_status_t *s = topmem + G_scroll_ofs;
         char *cp, ch;
 
-        display_topmem_header(scr_width, &lines_rem);
+        display_topmem_header();
 
-        strcpy(line_buf, HDR_STR " COMMAND");
+        strcpy(G.line_buf, "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK COMMAND");
         /* Mark the ^FIELD^ we sort by */
-        cp = &line_buf[5 + sort_field * 6];
+        cp = &G.line_buf[5 + sort_field * 6];
         ch = "^_"[inverted];
         cp[6] = ch;
         do *cp++ = ch; while (*cp == ' ');
+        print_line_bold();
 
-        printf(OPT_BATCH_MODE ? "%.*s" : ESC"[7m" "%.*s" ESC"[m", scr_width, line_buf);
-        lines_rem--;
-
-        if (lines_rem > ntop - G_scroll_ofs)
-                lines_rem = ntop - G_scroll_ofs;
-        while (--lines_rem >= 0) {
+        if (G.lines_remaining > ntop - G_scroll_ofs)
+                G.lines_remaining = ntop - G_scroll_ofs;
+        while (G.lines_remaining > 0) {
                 /* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
-                int n = sprintf(line_buf, "%5u ", s->pid);
+                int n = sprintf(G.line_buf, "%5u ", s->pid);
                 if (n > 7) {
                         /* PID is 7 chars long (up to 4194304) */
-                        ulltoa4_and_space(s->vsz  , &line_buf[8]);
-                        ulltoa4_and_space(s->vszrw, &line_buf[8+5]);
+                        ulltoa4_and_space(s->vsz  , &G.line_buf[8]);
+                        ulltoa4_and_space(s->vszrw, &G.line_buf[8+5]);
                         /* the next field (RSS) starts at 8+10 = 3*6 */
                 } else {
                         if (n == 7) /* PID is 6 chars long */
-                                ulltoa4_and_space(s->vsz, &line_buf[7]);
+                                ulltoa4_and_space(s->vsz, &G.line_buf[7]);
                                 /* the next field (VSZRW) starts at 7+5 = 2*6 */
                         else /* PID is 5 chars or less */
-                                ulltoa5_and_space(s->vsz, &line_buf[6]);
-                        ulltoa5_and_space(s->vszrw, &line_buf[2*6]);
-                }
-                ulltoa5_and_space(s->rss     , &line_buf[3*6]);
-                ulltoa5_and_space(s->rss_sh  , &line_buf[4*6]);
-                ulltoa5_and_space(s->dirty   , &line_buf[5*6]);
-                ulltoa5_and_space(s->dirty_sh, &line_buf[6*6]);
-                ulltoa5_and_space(s->stack   , &line_buf[7*6]);
-                line_buf[8*6] = '\0';
-                if (scr_width > (int)MIN_WIDTH) {
-                        read_cmdline(&line_buf[8*6], scr_width - MIN_WIDTH, s->pid, s->comm);
+                                ulltoa5_and_space(s->vsz, &G.line_buf[6]);
+                        ulltoa5_and_space(s->vszrw, &G.line_buf[2*6]);
                 }
-                printf("\n""%.*s", scr_width, line_buf);
+                ulltoa5_and_space(s->rss     , &G.line_buf[3*6]);
+                ulltoa5_and_space(s->rss_sh  , &G.line_buf[4*6]);
+                ulltoa5_and_space(s->dirty   , &G.line_buf[5*6]);
+                ulltoa5_and_space(s->dirty_sh, &G.line_buf[6*6]);
+                ulltoa5_and_space(s->stack   , &G.line_buf[7*6]);
+                G.line_buf[8*6] = '\0';
+                cmdline_to_line_buf_and_print(8*6, s->pid, s->comm);
                 s++;
         }
-        bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
-        fflush_all();
-#undef HDR_STR
-#undef MIN_WIDTH
 }
 
-#else
-void display_topmem_process_list(int lines_rem, int scr_width);
-int topmem_sort(char *a, char *b);
-#endif /* TOPMEM */
-
-/*
- * end TOPMEM support
- */
+#endif /* end TOPMEM support */
 
 enum {
         TOP_MASK = 0
                 | PSSCAN_PID
                 | PSSCAN_PPID
-                | PSSCAN_VSZ
+                | PSSCAN_RSS
                 | PSSCAN_STIME
                 | PSSCAN_UTIME
                 | PSSCAN_STATE
@@ -950,7 +977,7 @@ enum {
                 | PSSCAN_SMAPS
                 | PSSCAN_COMM,
         EXIT_MASK = 0,
-        NO_RESCAN_MASK = (unsigned)-1,
+        ONLY_REDRAW = (unsigned)-1,
 };
 
 #if ENABLE_FEATURE_TOP_INTERACTIVE
@@ -963,15 +990,22 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
         }
 
         while (1) {
-                int32_t c;
+                int32_t c, cc;
 
                 c = safe_read_key(STDIN_FILENO, G.kbd_input, interval * 1000);
-                if (c == -1 && errno != EAGAIN) {
-                        /* error/EOF */
-                        option_mask32 |= OPT_EOF;
+                if (c == -1) {
+                        if (errno != EAGAIN)
+                                /* error/EOF */
+                                option_mask32 |= OPT_EOF;
+                        /* else: timeout - rescan and refresh */
                         break;
                 }
                 interval = 0;
+                /* "continue" statements below return to do one additional
+                 * quick attempt to read a key. This prevents
+                 * long sequence of e.g. "nnnnnnnnnnnnnnnnnnnnnnnnnn"
+                 * to cause lots of rescans.
+                 */
 
                 if (c == initial_settings.c_cc[VINTR])
                         return EXIT_MASK;
@@ -1005,9 +1039,10 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
                                 G_scroll_ofs = ntop - 1;
                         if (G_scroll_ofs < 0)
                                 G_scroll_ofs = 0;
-                        return NO_RESCAN_MASK;
+                        return ONLY_REDRAW;
                 }
 
+                cc = c;
                 c |= 0x20; /* lowercase */
                 if (c == 'q')
                         return EXIT_MASK;
@@ -1055,9 +1090,17 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
                         continue;
                 }
 #  if ENABLE_FEATURE_TOPMEM
+                if (cc == 'S') {
+                        if (--sort_field < 0)
+                                sort_field = NUM_SORT_FIELD - 1;
+                        if (--sort_field < 0)
+                                sort_field = NUM_SORT_FIELD - 1;
+                }
                 if (c == 's') {
-                        scan_mask = TOPMEM_MASK;
                         sort_field = (sort_field + 1) % NUM_SORT_FIELD;
+                        if (scan_mask == TOPMEM_MASK)
+                                return ONLY_REDRAW;
+                        scan_mask = TOPMEM_MASK;
                         free(prev_hist);
                         prev_hist = NULL;
                         prev_hist_count = 0;
@@ -1066,7 +1109,7 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
 #  endif
                 if (c == 'r') {
                         inverted ^= 1;
-                        continue;
+                        return ONLY_REDRAW;
                 }
 #  if ENABLE_FEATURE_TOP_SMP_CPU
                 /* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
@@ -1088,8 +1131,8 @@ static unsigned handle_input(unsigned scan_mask, duration_t interval)
                 }
 #  endif
 # endif
-                break; /* unknown key -> force refresh */
-        }
+                /* Unknown key. Eat remaining buffered input (if any) */
+        } /* while (1) */
 
         return scan_mask;
 }
@@ -1155,7 +1198,7 @@ int top_main(int argc UNUSED_PARAM, char **argv)
 {
         duration_t interval;
         int iterations;
-        unsigned col;
+        unsigned opt;
         char *str_interval, *str_iterations;
         unsigned scan_mask = TOP_MASK;
 
@@ -1172,13 +1215,13 @@ int top_main(int argc UNUSED_PARAM, char **argv)
 
         /* all args are options; -n NUM */
         make_all_argv_opts(argv); /* options can be specified w/o dash */
-        col = getopt32(argv, "d:n:bHm", &str_interval, &str_iterations);
+        opt = getopt32(argv, "d:n:bHm", &str_interval, &str_iterations);
         /* NB: -m and -H are accepted even if not configured */
 #if ENABLE_FEATURE_TOPMEM
-        if (col & OPT_m) /* -m (busybox specific) */
+        if (opt & OPT_m) /* -m (busybox specific) */
                 scan_mask = TOPMEM_MASK;
 #endif
-        if (col & OPT_d) {
+        if (opt & OPT_d) {
                 /* work around for "-d 1" -> "-d -1" done by make_all_argv_opts() */
                 if (str_interval[0] == '-')
                         str_interval++;
@@ -1187,18 +1230,17 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                 if (interval > INT_MAX / 1000)
                         interval = INT_MAX / 1000;
         }
-        if (col & OPT_n) {
+        if (opt & OPT_n) {
                 if (str_iterations[0] == '-')
                         str_iterations++;
                 iterations = xatou(str_iterations);
         }
 #if ENABLE_FEATURE_SHOW_THREADS
-        if (col & OPT_H) {
+        if (opt & OPT_H) {
                 scan_mask |= PSSCAN_TASKS;
         }
 #endif
 
-        /* change to /proc */
         xchdir("/proc");
 
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
@@ -1226,23 +1268,22 @@ int top_main(int argc UNUSED_PARAM, char **argv)
 #endif
 
         while (scan_mask != EXIT_MASK) {
-                IF_FEATURE_TOP_INTERACTIVE(unsigned new_mask;)
+                IF_FEATURE_TOP_INTERACTIVE(unsigned new_mask = scan_mask;)
                 procps_status_t *p = NULL;
 
-                if (OPT_BATCH_MODE) {
-                        G.lines = INT_MAX;
-                        col = LINE_BUF_SIZE - 2; /* +2 bytes for '\n', NUL */
-                } else {
+                G.lines = INT_MAX;
+                G.scr_width = LINE_BUF_SIZE - 2; /* +2 bytes for '\n', NUL */
+                if (!OPT_BATCH_MODE) {
                         G.lines = 24; /* default */
-                        col = 79;
+                        G.scr_width = 80;
                         /* 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) {
+                        get_terminal_width_height(STDOUT_FILENO, &G.scr_width, &G.lines);
+                        if (G.lines < 5 || G.scr_width < 10) {
                                 sleep_for_duration(interval);
                                 continue;
                         }
-                        if (col > LINE_BUF_SIZE - 2)
-                                col = LINE_BUF_SIZE - 2;
+                        if (G.scr_width > LINE_BUF_SIZE - 2)
+                                G.scr_width = LINE_BUF_SIZE - 2;
                 }
 
                 /* read process IDs & status for all the processes */
@@ -1255,7 +1296,7 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                                 top = xrealloc_vector(top, 6, ntop++);
                                 top[n].pid = p->pid;
                                 top[n].ppid = p->ppid;
-                                top[n].vsz = p->vsz;
+                                top[n].memsize = p->rss;
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
                                 top[n].ticks = p->stime + p->utime;
 #endif
@@ -1268,20 +1309,20 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                         }
 #if ENABLE_FEATURE_TOPMEM
                         else { /* TOPMEM */
-                                if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
+                                if (!(p->mapped_ro | p->mapped_rw))
                                         continue; /* kernel threads are ignored */
                                 n = ntop;
                                 /* 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->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;
+                                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
                 } /* end of "while we read /proc" */
@@ -1310,30 +1351,40 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                         qsort(topmem, ntop, sizeof(topmem_status_t), (void*)topmem_sort);
                 }
 #endif
- IF_FEATURE_TOP_INTERACTIVE(display:)
+ IF_FEATURE_TOP_INTERACTIVE(redraw:)
+                G.lines_remaining = G.lines;
                 IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
-                        display_process_list(G.lines, col);
+                        display_process_list();
                 }
 #if ENABLE_FEATURE_TOPMEM
                 else { /* TOPMEM */
-                        display_topmem_process_list(G.lines, col);
+                        display_topmem_process_list();
                 }
 #endif
+                print_end();
+                fflush_all();
                 if (iterations >= 0 && !--iterations)
                         break;
 #if !ENABLE_FEATURE_TOP_INTERACTIVE
                 clearmems();
                 sleep_for_duration(interval);
 #else
-                new_mask = handle_input(scan_mask, interval);
-                if (new_mask == NO_RESCAN_MASK)
-                        goto display;
+                new_mask = handle_input(scan_mask,
+                        /* After "redraw with no rescan", have one
+                         * key timeout shorter that normal
+                         * (IOW: rescan sooner):
+                         */
+                        (new_mask == ONLY_REDRAW ? 1 : interval)
+                );
+                if (new_mask == ONLY_REDRAW)
+                        goto redraw;
                 scan_mask = new_mask;
                 clearmems();
 #endif
         } /* end of "while (not Q)" */
 
-        bb_putchar('\n');
+        if (!OPT_BATCH_MODE)
+                bb_putchar('\n');
 #if ENABLE_FEATURE_TOP_INTERACTIVE
         reset_term();
 #endif