perf_counter tools: remove glib dependency and fix bugs in kerneltop.c

The glib dependency in kerneltop.c is only for a little bit of list
manipulation, and I find it inconvenient.  This adds a 'next' field to
struct source_line, which lets us link them together into a list.  The
code to do the linking ourselves turns out to be no longer or more
difficult than using glib.

This also fixes a few other problems:

- We need to #include <limits.h> to get PATH_MAX on powerpc.

- We need to #include <linux/types.h> rather than have our own
  definitions of __u64 and __s64; on powerpc the installed headers
  define them to be unsigned long and long respectively, and if we
  have our own, different definition here that causes a compile error.

- This takes out the x86 setting of errno from -ret in
  sys_perf_counter_open.  My experiments on x86 indicate that the
  glibc syscall() does this for us already.

- We had two CPU migration counters in the default set, which seems
  unnecessary; I changed one of them to a context switch counter.

- In perfstat mode we were printing CPU cycles and instructions as
  milliseconds, and the cpu clock and task clock counters as events.
  This fixes that.

- In perfstat mode we were still printing a blank line after the first
  counter, which was a holdover from when a task clock counter was
  automatically included as the first counter.  This removes the blank
  line.

- On a test machine here, parse_symbols() and parse_vmlinux() were
  taking long enough (almost 0.5 seconds) for the mmap buffer to
  overflow before we got to the first mmap_read() call, so this moves
  them before we open all the counters.

- The error message if sys_perf_counter_open fails needs to use errno,
  not -fd[i][counter].

Signed-off-by: Paul Mackerras <paulus@samba.org>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Mike Galbraith <efault@gmx.de>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Orig-LKML-Reference: <18888.29986.340328.540512@cargo.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 46 insertions, 68 deletions

diff --git a/Documentation/perf_counter/Makefile b/Documentation/perf_counter/Makefile
index 666da95a7877..194b66215588 100644
--- a/Documentation/perf_counter/Makefile
+++ b/Documentation/perf_counter/Makefile
@@ -3,7 +3,7 @@ BINS = kerneltop perfstat
 all: $(BINS)
 
 kerneltop: kerneltop.c ../../include/linux/perf_counter.h
-        cc -O6 -Wall -lrt `pkg-config --cflags --libs glib-2.0` -o $@ $<
+        cc -O6 -Wall -lrt -o $@ $<
 
 perfstat: kerneltop
         ln -sf kerneltop perfstat
diff --git a/Documentation/perf_counter/kerneltop.c b/Documentation/perf_counter/kerneltop.c
index 2ab29b5e32e8..ea13e4e67229 100644
--- a/Documentation/perf_counter/kerneltop.c
+++ b/Documentation/perf_counter/kerneltop.c
@@ -3,7 +3,7 @@
 
    Build with:
 
-     cc -O6 -Wall -lrt `pkg-config --cflags --libs glib-2.0` -o kerneltop kerneltop.c
+     cc -O6 -Wall -c -o kerneltop.o kerneltop.c -lrt
 
    Sample output:
 
@@ -56,6 +56,7 @@
   *   Yanmin Zhang <yanmin.zhang@intel.com>
   *   Wu Fengguang <fengguang.wu@intel.com>
   *   Mike Galbraith <efault@gmx.de>
+  *   Paul Mackerras <paulus@samba.org>
   *
   * Released under the GPL v2. (and only v2, not any later version)
   */
@@ -68,6 +69,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
 #include <getopt.h>
 #include <assert.h>
 #include <fcntl.h>
@@ -76,8 +78,6 @@
 #include <ctype.h>
 #include <time.h>
 
-#include <glib.h>
-
 #include <sys/syscall.h>
 #include <sys/ioctl.h>
 #include <sys/poll.h>
@@ -87,6 +87,7 @@
 #include <sys/mman.h>
 
 #include <linux/unistd.h>
+#include <linux/types.h>
 
 #include "../../include/linux/perf_counter.h"
 
@@ -114,11 +115,6 @@
 #define __user
 #define asmlinkage
 
-typedef unsigned int            __u32;
-typedef unsigned long long      __u64;
-typedef long long               __s64;
-
-
 #ifdef __x86_64__
 #define __NR_perf_counter_open 295
 #define rmb()           asm volatile("lfence" ::: "memory")
@@ -146,17 +142,8 @@ asmlinkage int sys_perf_counter_open(
         int                             group_fd,
         unsigned long                   flags)
 {
-        int ret;
-
-        ret = syscall(
+        return syscall(
                 __NR_perf_counter_open, hw_event_uptr, pid, cpu, group_fd, flags);
-#if defined(__x86_64__) || defined(__i386__)
-        if (ret < 0 && ret > -4096) {
-                errno = -ret;
-                ret = -1;
-        }
-#endif
-        return ret;
 }
 
 #define MAX_COUNTERS                    64
@@ -170,7 +157,7 @@ static int			system_wide			=  0;
 static int                      nr_counters                     =  0;
 static __u64                    event_id[MAX_COUNTERS]          = {
         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK),
-        EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
+        EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES),
         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
         EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS),
 
@@ -202,14 +189,15 @@ static int			delay_secs			=  2;
 static int                      zero;
 static int                      dump_symtab;
 
-static GList                    *lines;
-
 struct source_line {
         uint64_t                EIP;
         unsigned long           count;
         char                    *line;
+        struct source_line      *next;
 };
 
+static struct source_line       *lines;
+static struct source_line       **lines_tail;
 
 const unsigned int default_count[] = {
         1000000,
@@ -519,9 +507,8 @@ int do_perfstat(int argc, char *argv[])
                         count += single_count;
                 }
 
-                if (!PERF_COUNTER_RAW(event_id[counter]) &&
-                    (event_id[counter] == PERF_COUNT_CPU_CLOCK ||
-                     event_id[counter] == PERF_COUNT_TASK_CLOCK)) {
+                if (event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_CLOCK) ||
+                    event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK)) {
 
                         double msecs = (double)count / 1000000;
 
@@ -531,8 +518,6 @@ int do_perfstat(int argc, char *argv[])
                         fprintf(stderr, " %14Ld  %-20s (events)\n",
                                 count, event_name(counter));
                 }
-                if (!counter)
-                        fprintf(stderr, "\n");
         }
         fprintf(stderr, "\n");
         fprintf(stderr, " Wall-clock time elapsed: %12.6f msecs\n",
@@ -554,7 +539,7 @@ struct sym_entry {
         char                    *sym;
         unsigned long           count[MAX_COUNTERS];
         int                     skip;
-        GList                   *source;
+        struct source_line      *source;
 };
 
 #define MAX_SYMS                100000
@@ -855,6 +840,7 @@ static void parse_vmlinux(char *filename)
         if (!file)
                 return;
 
+        lines_tail = &lines;
         while (!feof(file)) {
                 struct source_line *src;
                 size_t dummy = 0;
@@ -873,7 +859,9 @@ static void parse_vmlinux(char *filename)
                 if (c)
                         *c = 0;
 
-                lines = g_list_prepend(lines, src);
+                src->next = NULL;
+                *lines_tail = src;
+                lines_tail = &src->next;
 
                 if (strlen(src->line)>8 && src->line[8] == ':')
                         src->EIP = strtoull(src->line, NULL, 16);
@@ -881,52 +869,43 @@ static void parse_vmlinux(char *filename)
                         src->EIP = strtoull(src->line, NULL, 16);
         }
         pclose(file);
-        lines = g_list_reverse(lines);
 }
 
 static void record_precise_ip(uint64_t ip)
 {
         struct source_line *line;
-        GList *item;
 
-        item = g_list_first(lines);
-        while (item) {
-                line = item->data;
+        for (line = lines; line; line = line->next) {
                 if (line->EIP == ip)
                         line->count++;
                 if (line->EIP > ip)
                         break;
-                item = g_list_next(item);
         }
 }
 
 static void lookup_sym_in_vmlinux(struct sym_entry *sym)
 {
         struct source_line *line;
-        GList *item;
         char pattern[PATH_MAX];
         sprintf(pattern, "<%s>:", sym->sym);
 
-        item = g_list_first(lines);
-        while (item) {
-                line = item->data;
+        for (line = lines; line; line = line->next) {
                 if (strstr(line->line, pattern)) {
-                        sym->source = item;
+                        sym->source = line;
                         break;
                 }
-                item = g_list_next(item);
         }
 }
 
-void show_lines(GList *item_queue, int item_queue_count)
+static void show_lines(struct source_line *line_queue, int line_queue_count)
 {
         int i;
         struct source_line *line;
 
-        for (i = 0; i < item_queue_count; i++) {
-                line = item_queue->data;
+        line = line_queue;
+        for (i = 0; i < line_queue_count; i++) {
                 printf("%8li\t%s\n", line->count, line->line);
-                item_queue = g_list_next(item_queue);
+                line = line->next;
         }
 }
 
@@ -935,10 +914,9 @@ void show_lines(GList *item_queue, int item_queue_count)
 static void show_details(struct sym_entry *sym)
 {
         struct source_line *line;
-        GList *item;
+        struct source_line *line_queue = NULL;
         int displayed = 0;
-        GList *item_queue = NULL;
-        int item_queue_count = 0;
+        int line_queue_count = 0;
 
         if (!sym->source)
                 lookup_sym_in_vmlinux(sym);
@@ -947,30 +925,29 @@ static void show_details(struct sym_entry *sym)
 
         printf("Showing details for %s\n", sym->sym);
 
-        item = sym->source;
-        while (item) {
-                line = item->data;
+        line = sym->source;
+        while (line) {
                 if (displayed && strstr(line->line, ">:"))
                         break;
 
-                if (!item_queue_count)
-                        item_queue = item;
-                item_queue_count ++;
+                if (!line_queue_count)
+                        line_queue = line;
+                line_queue_count ++;
 
                 if (line->count >= count_filter) {
-                        show_lines(item_queue, item_queue_count);
-                        item_queue_count = 0;
-                        item_queue = NULL;
-                } else if (item_queue_count > TRACE_COUNT) {
-                        item_queue = g_list_next(item_queue);
-                        item_queue_count --;
+                        show_lines(line_queue, line_queue_count);
+                        line_queue_count = 0;
+                        line_queue = NULL;
+                } else if (line_queue_count > TRACE_COUNT) {
+                        line_queue = line_queue->next;
+                        line_queue_count --;
                 }
 
                 line->count = 0;
                 displayed++;
                 if (displayed > 300)
                         break;
-                item = g_list_next(item);
+                line = line->next;
         }
 }
 
@@ -1201,6 +1178,10 @@ int main(int argc, char *argv[])
         if (tid != -1 || profile_cpu != -1)
                 nr_cpus = 1;
 
+        parse_symbols();
+        if (vmlinux && sym_filter_entry)
+                parse_vmlinux(vmlinux);
+
         for (i = 0; i < nr_cpus; i++) {
                 group_fd = -1;
                 for (counter = 0; counter < nr_counters; counter++) {
@@ -1216,15 +1197,16 @@ int main(int argc, char *argv[])
                         hw_event.nmi            = nmi;
 
                         fd[i][counter] = sys_perf_counter_open(&hw_event, tid, cpu, group_fd, 0);
-                        fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
                         if (fd[i][counter] < 0) {
+                                int err = errno;
                                 printf("kerneltop error: syscall returned with %d (%s)\n",
-                                        fd[i][counter], strerror(-fd[i][counter]));
-                                if (fd[i][counter] == -1)
+                                        fd[i][counter], strerror(err));
+                                if (err == EPERM)
                                         printf("Are you root?\n");
                                 exit(-1);
                         }
                         assert(fd[i][counter] >= 0);
+                        fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
 
                         /*
                          * First counter acts as the group leader:
@@ -1248,10 +1230,6 @@ int main(int argc, char *argv[])
                 }
         }
 
-        parse_symbols();
-        if (vmlinux && sym_filter_entry)
-                parse_vmlinux(vmlinux);
-
         printf("KernelTop refresh period: %d seconds\n", delay_secs);
         last_refresh = time(NULL);