auto import from //depot/cupcake/@135843

1 files changed, 442 insertions, 0 deletions

diff --git a/latencytop/latencytop.c b/latencytop/latencytop.c
new file mode 100644
index 00000000..78d7c71d
--- /dev/null
+++ b/latencytop/latencytop.c
@@ -0,0 +1,442 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#define MAX_LINE 512
+#define MAX_FILENAME 64
+
+const char *EXPECTED_VERSION = "Latency Top version : v0.1\n";
+const char *SYSCTL_FILE = "/proc/sys/kernel/latencytop";
+const char *GLOBAL_STATS_FILE = "/proc/latency_stats";
+const char *THREAD_STATS_FILE_FORMAT = "/proc/%d/task/%d/latency";
+
+struct latency_entry {
+    struct latency_entry *next;
+    unsigned long count;
+    unsigned long max;
+    unsigned long total;
+    char reason[MAX_LINE];
+};
+
+static inline void check_latencytop() { }
+
+static struct latency_entry *read_global_stats(struct latency_entry *list, int erase);
+static struct latency_entry *read_process_stats(struct latency_entry *list, int erase, int pid);
+static struct latency_entry *read_thread_stats(struct latency_entry *list, int erase, int pid, int tid, int fatal);
+
+static struct latency_entry *alloc_latency_entry(void);
+static void free_latency_entry(struct latency_entry *e);
+
+static void set_latencytop(int on);
+static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list);
+static void erase_latency_file(FILE *f);
+
+static struct latency_entry *find_latency_entry(struct latency_entry *e, char *reason);
+static void print_latency_entries(struct latency_entry *head);
+
+static void signal_handler(int sig);
+static void disable_latencytop(void);
+
+static int numcmp(const long long a, const long long b);
+static int lat_cmp(const void *a, const void *b);
+
+static void clear_screen(void);
+static void usage(const char *cmd);
+
+struct latency_entry *free_entries;
+
+int main(int argc, char *argv[]) {
+    struct latency_entry *e;
+    int delay, iterations;
+    int pid, tid;
+    int count, erase;
+    int i;
+
+    delay = 1;
+    iterations = 0;
+    pid = tid = 0;
+    
+    for (i = 1; i < argc; i++) {
+        if (!strcmp(argv[i], "-d")) {
+            if (i >= argc - 1) {
+                fprintf(stderr, "Option -d expects an argument.\n");
+                exit(EXIT_FAILURE);
+            }
+            delay = atoi(argv[++i]);
+            continue;
+        }
+        if (!strcmp(argv[i], "-n")) {
+            if (i >= argc - 1) {
+                fprintf(stderr, "Option -n expects an argument.\n");
+                exit(EXIT_FAILURE);
+            }
+            iterations = atoi(argv[++i]);
+            continue;
+        }
+        if (!strcmp(argv[i], "-h")) {
+            usage(argv[0]);
+            exit(EXIT_SUCCESS);
+        }
+        if (!strcmp(argv[i], "-p")) {
+            if (i >= argc - 1) {
+                fprintf(stderr, "Option -p expects an argument.\n");
+                exit(EXIT_FAILURE);
+            }
+            pid = atoi(argv[++i]);
+            continue;
+        }
+        if (!strcmp(argv[i], "-t")) {
+            if (i >= argc - 1) {
+                fprintf(stderr, "Option -t expects an argument.\n");
+                exit(EXIT_FAILURE);
+            }
+            tid = atoi(argv[++i]);
+            continue;
+        }
+        fprintf(stderr, "Invalid argument \"%s\".\n", argv[i]);
+        usage(argv[0]);
+        exit(EXIT_FAILURE);
+    }
+
+    if (tid && !pid) {
+        fprintf(stderr, "If you provide a thread ID with -t, you must provide a process ID with -p.\n");
+        exit(EXIT_FAILURE);
+    }
+
+    check_latencytop();
+
+    free_entries = NULL;
+
+    signal(SIGINT, &signal_handler);
+    signal(SIGTERM, &signal_handler);
+
+    atexit(&disable_latencytop);
+
+    set_latencytop(1);
+
+    count = 0;
+    erase = 1;
+
+    while ((iterations == 0) || (count++ < iterations)) {
+
+        sleep(delay);
+
+        e = NULL;
+        if (pid) {
+            if (tid) {
+                e = read_thread_stats(e, erase, pid, tid, 1);
+            } else {
+                e = read_process_stats(e, erase, pid);
+            }
+        } else {
+            e = read_global_stats(e, erase);
+        }
+        erase = 0;
+
+        clear_screen();
+        if (pid) {
+            if (tid) {
+                printf("Latencies for thread %d in process %d:\n", tid, pid);
+            } else {
+                printf("Latencies for process %d:\n", pid);
+            }
+        } else {
+            printf("Latencies across all processes:\n");
+        }
+        print_latency_entries(e);
+    }
+
+    set_latencytop(0);
+
+    return 0;
+}
+
+static struct latency_entry *read_global_stats(struct latency_entry *list, int erase) {
+    FILE *f;
+    struct latency_entry *e;
+
+    if (erase) {
+        f = fopen(GLOBAL_STATS_FILE, "w");
+        if (!f) {
+            fprintf(stderr, "Could not open global latency stats file: %s\n", strerror(errno));
+            exit(EXIT_FAILURE);
+        }
+        fprintf(f, "erase\n");
+        fclose(f);
+    }
+    
+    f = fopen(GLOBAL_STATS_FILE, "r");
+    if (!f) {
+        fprintf(stderr, "Could not open global latency stats file: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    e = read_latency_file(f, list);
+
+    fclose(f);
+
+    return e;
+}
+
+static struct latency_entry *read_process_stats(struct latency_entry *list, int erase, int pid) {
+    char dirname[MAX_FILENAME];
+    DIR *dir;
+    struct dirent *ent;
+    struct latency_entry *e;
+    int tid;
+
+    sprintf(dirname, "/proc/%d/task", pid);
+    dir = opendir(dirname);
+    if (!dir) {
+        fprintf(stderr, "Could not open task dir for process %d.\n", pid);
+        fprintf(stderr, "Perhaps the process has terminated?\n");
+        exit(EXIT_FAILURE);
+    }
+
+    e = list;
+    while ((ent = readdir(dir))) {
+        if (!isdigit(ent->d_name[0]))
+            continue;
+
+        tid = atoi(ent->d_name);
+
+        e = read_thread_stats(e, erase, pid, tid, 0);
+    }
+
+    closedir(dir);
+
+    return e;
+}
+
+static struct latency_entry *read_thread_stats(struct latency_entry *list, int erase, int pid, int tid, int fatal) {
+    char filename[MAX_FILENAME];
+    FILE *f;
+    struct latency_entry *e;
+
+    sprintf(filename, THREAD_STATS_FILE_FORMAT, pid, tid);
+
+    if (erase) {
+        f = fopen(filename, "w");
+        if (!f) {
+            if (fatal) {
+                fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
+                fprintf(stderr, "Perhaps the process or thread has terminated?\n");
+                exit(EXIT_FAILURE);
+            } else {
+                return list;
+            }
+        }
+        fprintf(f, "erase\n");
+        fclose(f);
+    }
+    
+    f = fopen(GLOBAL_STATS_FILE, "r");
+    if (!f) {
+        if (fatal) {
+            fprintf(stderr, "Could not open %s: %s\n", filename, strerror(errno));
+            fprintf(stderr, "Perhaps the process or thread has terminated?\n");
+            exit(EXIT_FAILURE);
+        } else {
+            return list;
+        }
+    }
+
+    e = read_latency_file(f, list);
+
+    fclose(f);
+
+    return e;
+}
+
+static struct latency_entry *alloc_latency_entry(void) {
+    struct latency_entry *e;
+
+    if (free_entries) {
+        e = free_entries;
+        free_entries = free_entries->next;
+    } else {
+        e = calloc(1, sizeof(struct latency_entry));
+        if (!e) {
+            fprintf(stderr, "Could not allocate latency entry: %s\n", strerror(errno));
+            exit(EXIT_FAILURE);
+        }
+    }
+
+    return e;
+}
+
+static void free_latency_entry(struct latency_entry *e) {
+    e->next = free_entries;
+    free_entries = e;
+}
+
+static struct latency_entry *find_latency_entry(struct latency_entry *head, char *reason) {
+    struct latency_entry *e;
+
+    e = head;
+
+    while (e) {
+        if (!strcmp(e->reason, reason))
+            return e;
+        e = e->next;
+    }
+
+    return NULL;
+}
+
+static void set_latencytop(int on) {
+    FILE *f;
+
+    f = fopen(SYSCTL_FILE, "w");
+    if (!f) {
+        fprintf(stderr, "Could not open %s: %s\n", SYSCTL_FILE, strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    fprintf(f, "%d\n", on);
+
+    fclose(f);
+}
+
+static void erase_latency_file(FILE *f) {
+    fprintf(f, "erase\n");
+}
+
+static struct latency_entry *read_latency_file(FILE *f, struct latency_entry *list) {
+    struct latency_entry *e, *head;
+    char line[MAX_LINE];
+    unsigned long count, max, total;
+    char reason[MAX_LINE];
+
+    head = list;
+
+    if (!fgets(line, MAX_LINE, f)) {
+        fprintf(stderr, "Could not read latency file version: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    if (strcmp(line, EXPECTED_VERSION) != 0) {
+        fprintf(stderr, "Expected version: %s\n", EXPECTED_VERSION);
+        fprintf(stderr, "But got version: %s", line);
+        exit(EXIT_FAILURE);
+    }
+
+    while (fgets(line, MAX_LINE, f)) {
+        sscanf(line, "%ld %ld %ld %s", &count, &total, &max, reason);
+        if (max > 0 || total > 0) {
+            e = find_latency_entry(head, reason);
+            if (e) {
+                e->count += count;
+                if (max > e->max)
+                    e->max = max;
+                e->total += total;
+            } else {
+                e = alloc_latency_entry();
+                e->count = count;
+                e->max = max;
+                e->total = total;
+                strcpy(e->reason, reason);
+                e->next = head;
+                head = e;
+            }
+        }
+    }
+
+    return head;
+}
+
+static void print_latency_entries(struct latency_entry *head) {
+    struct latency_entry *e, **array;
+    unsigned long average;
+    int i, count;
+
+    e = head;
+    count = 0;
+    while (e) {
+        count++;
+        e = e->next;
+    }
+
+    e = head;
+    array = calloc(count, sizeof(struct latency_entry *));
+    if (!array) {
+        fprintf(stderr, "Error allocating array: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    for (i = 0; i < count; i++) {
+        array[i] = e;
+        e = e->next;
+    }
+
+    qsort(array, count, sizeof(struct latency_entry *), &lat_cmp);
+
+    printf("%10s  %10s  %7s  %s\n", "Maximum", "Average", "Count", "Reason");
+    for (i = 0; i < count; i++) {
+        e = array[i];
+        average = e->total / e->count;
+        printf("%4lu.%02lu ms  %4lu.%02lu ms  %7ld  %s\n",
+            e->max / 1000, (e->max % 1000) / 10,
+            average / 1000, (average % 1000) / 10,
+            e->count,
+            e->reason);
+    }
+
+    free(array);
+}
+
+static void signal_handler(int sig) {
+    exit(EXIT_SUCCESS);
+}
+
+static void disable_latencytop(void) {
+    set_latencytop(0);
+}
+
+static void clear_screen(void) {
+    printf("\n\n");
+}
+
+static void usage(const char *cmd) {
+    fprintf(stderr, "Usage: %s [ -d delay ] [ -n iterations ] [ -p pid [ -t tid ] ] [ -h ]\n"
+                    "    -d delay       Time to sleep between updates.\n"
+                    "    -n iterations  Number of updates to show (0 = infinite).\n"
+                    "    -p pid         Process to monitor (default is all).\n"
+                    "    -t tid         Thread (within specified process) to monitor (default is all).\n"
+                    "    -h             Display this help screen.\n",
+        cmd);
+}
+
+static int numcmp(const long long a, const long long b) {
+    if (a < b) return -1;
+    if (a > b) return 1;
+    return 0;
+}
+
+static int lat_cmp(const void *a, const void *b) {
+    const struct latency_entry *pa, *pb;
+
+    pa = (*((struct latency_entry **)a));
+    pb = (*((struct latency_entry **)b));
+
+    return numcmp(pb->max, pa->max);
+}