perf kmem: Collect cross node allocation statistics

Show cross node memory allocations:

 # ./perf kmem

 SUMMARY
 =======
 ...
 Cross node allocations: 0/3633

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: linux-mm@kvack.org <linux-mm@kvack.org>
LKML-Reference: <4B0B6E87.10906@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/tools/perf/builtin-kmem.c b/tools/perf/builtin-kmem.c
index dc86f1e64b66b2ca8831d366607e5c2f7051bbaa..1ecf3f4415cecc20ac989ca039b18cc9e94f716c 100644 (file)
--- a/tools/perf/builtin-kmem.c
+++ b/tools/perf/builtin-kmem.c
@@ -36,6 +36,9 @@ static char                   default_sort_order[] = "frag,hit,bytes";
 static char                    *cwd;
 static int                     cwdlen;
 
+static int                     *cpunode_map;
+static int                     max_cpu_num;
+
 struct alloc_stat {
        union {
                u64     call_site;
@@ -54,12 +57,74 @@ static struct rb_root root_caller_stat;
 static struct rb_root root_caller_sorted;
 
 static unsigned long total_requested, total_allocated;
+static unsigned long nr_allocs, nr_cross_allocs;
 
 struct raw_event_sample {
        u32 size;
        char data[0];
 };
 
+#define PATH_SYS_NODE  "/sys/devices/system/node"
+
+static void init_cpunode_map(void)
+{
+       FILE *fp;
+       int i;
+
+       fp = fopen("/sys/devices/system/cpu/kernel_max", "r");
+       if (!fp) {
+               max_cpu_num = 4096;
+               return;
+       }
+
+       if (fscanf(fp, "%d", &max_cpu_num) < 1)
+               die("Failed to read 'kernel_max' from sysfs");
+       max_cpu_num++;
+
+       cpunode_map = calloc(max_cpu_num, sizeof(int));
+       if (!cpunode_map)
+               die("calloc");
+       for (i = 0; i < max_cpu_num; i++)
+               cpunode_map[i] = -1;
+       fclose(fp);
+}
+
+static void setup_cpunode_map(void)
+{
+       struct dirent *dent1, *dent2;
+       DIR *dir1, *dir2;
+       unsigned int cpu, mem;
+       char buf[PATH_MAX];
+
+       init_cpunode_map();
+
+       dir1 = opendir(PATH_SYS_NODE);
+       if (!dir1)
+               return;
+
+       while (true) {
+               dent1 = readdir(dir1);
+               if (!dent1)
+                       break;
+
+               if (sscanf(dent1->d_name, "node%u", &mem) < 1)
+                       continue;
+
+               snprintf(buf, PATH_MAX, "%s/%s", PATH_SYS_NODE, dent1->d_name);
+               dir2 = opendir(buf);
+               if (!dir2)
+                       continue;
+               while (true) {
+                       dent2 = readdir(dir2);
+                       if (!dent2)
+                               break;
+                       if (sscanf(dent2->d_name, "cpu%u", &cpu) < 1)
+                               continue;
+                       cpunode_map[cpu] = mem;
+               }
+       }
+}
+
 static int
 process_comm_event(event_t *event, unsigned long offset, unsigned long head)
 {
@@ -157,15 +222,16 @@ static void insert_caller_stat(unsigned long call_site,
 
 static void process_alloc_event(struct raw_event_sample *raw,
                                struct event *event,
-                               int cpu __used,
+                               int cpu,
                                u64 timestamp __used,
                                struct thread *thread __used,
-                               int node __used)
+                               int node)
 {
        unsigned long call_site;
        unsigned long ptr;
        int bytes_req;
        int bytes_alloc;
+       int node1, node2;
 
        ptr = raw_field_value(event, "ptr", raw->data);
        call_site = raw_field_value(event, "call_site", raw->data);
@@ -177,6 +243,14 @@ static void process_alloc_event(struct raw_event_sample *raw,
 
        total_requested += bytes_req;
        total_allocated += bytes_alloc;
+
+       if (node) {
+               node1 = cpunode_map[cpu];
+               node2 = raw_field_value(event, "node", raw->data);
+               if (node1 != node2)
+                       nr_cross_allocs++;
+       }
+       nr_allocs++;
 }
 
 static void process_free_event(struct raw_event_sample *raw __used,
@@ -359,6 +433,7 @@ static void print_summary(void)
               total_allocated - total_requested);
        printf("Internal fragmentation: %f%%\n",
               fragmentation(total_requested, total_allocated));
+       printf("Cross CPU allocations: %lu/%lu\n", nr_cross_allocs, nr_allocs);
 }
 
 static void print_result(void)
@@ -685,6 +760,8 @@ int cmd_kmem(int argc, const char **argv, const char *prefix __used)
        if (list_empty(&alloc_sort))
                setup_sorting(&alloc_sort, default_sort_order);
 
+       setup_cpunode_map();
+
        return __cmd_kmem();
 }