Prefer new zram ABI
Starting with Linux 4.1, reading from /dev/block/zram*/mem_used_total
logs this warning:
"Attribute mem_used_total (and others) will be removed. See zram
documentation."
mem_used_total and several related counters are now consolidated under a
new node mm_stat. Prefer that when it's available.
Bug: 25951511
Change-Id: I0862c3cd1af5d003158aca6be42db25e4bebe7c7
Signed-off-by: Greg Hackmann <ghackmann@google.com>
diff --git a/core/jni/android_os_Debug.cpp b/core/jni/android_os_Debug.cpp
index 1ee7ea8..71f881e 100644
--- a/core/jni/android_os_Debug.cpp
+++ b/core/jni/android_os_Debug.cpp
@@ -595,6 +595,36 @@
MEMINFO_COUNT
};
+static long get_zram_mem_used()
+{
+#define ZRAM_SYSFS "/sys/block/zram0/"
+ FILE *f = fopen(ZRAM_SYSFS "mm_stat", "r");
+ if (f) {
+ long mem_used_total = 0;
+
+ int matched = fscanf(f, "%*d %*d %ld %*d %*d %*d %*d", &mem_used_total);
+ if (matched != 1)
+ ALOGW("failed to parse " ZRAM_SYSFS "mm_stat");
+
+ fclose(f);
+ return mem_used_total;
+ }
+
+ f = fopen(ZRAM_SYSFS "mem_used_total", "r");
+ if (f) {
+ long mem_used_total = 0;
+
+ int matched = fscanf(f, "%ld", &mem_used_total);
+ if (matched != 1)
+ ALOGW("failed to parse " ZRAM_SYSFS "mem_used_total");
+
+ fclose(f);
+ return mem_used_total;
+ }
+
+ return 0;
+}
+
static void android_os_Debug_getMemInfo(JNIEnv *env, jobject clazz, jlongArray out)
{
char buffer[1024];
@@ -680,15 +710,7 @@
if (*p) p++;
}
- fd = open("/sys/block/zram0/mem_used_total", O_RDONLY);
- if (fd >= 0) {
- len = read(fd, buffer, sizeof(buffer)-1);
- close(fd);
- if (len > 0) {
- buffer[len] = 0;
- mem[MEMINFO_ZRAM_TOTAL] = atoll(buffer)/1024;
- }
- }
+ mem[MEMINFO_ZRAM_TOTAL] = get_zram_mem_used() / 1024;
// Recompute Vmalloc Used since the value in meminfo
// doesn't account for I/O remapping which doesn't use RAM.
mem[MEMINFO_VMALLOC_USED] = get_allocated_vmalloc_memory() / 1024;