dumpstate: refine calculated eMMC performance values
Correct the raw performance with the average queue depth. Add a
report for I/O per second, and the average queue depth. Round
values up.
Bug: 26966375
Change-Id: I2a8d233872d5e5ff79d433abba3c34d5945701f4
diff --git a/cmds/dumpstate/dumpstate.cpp b/cmds/dumpstate/dumpstate.cpp
index 84a0100..db12bf2 100644
--- a/cmds/dumpstate/dumpstate.cpp
+++ b/cmds/dumpstate/dumpstate.cpp
@@ -113,8 +113,88 @@
static const char mmcblk0[] = "/sys/block/mmcblk0/";
unsigned long worst_write_perf = 20000; /* in KB/s */
+//
+// stat offsets
+// Name units description
+// ---- ----- -----------
+// read I/Os requests number of read I/Os processed
+#define __STAT_READ_IOS 0
+// read merges requests number of read I/Os merged with in-queue I/O
+#define __STAT_READ_MERGES 1
+// read sectors sectors number of sectors read
+#define __STAT_READ_SECTORS 2
+// read ticks milliseconds total wait time for read requests
+#define __STAT_READ_TICKS 3
+// write I/Os requests number of write I/Os processed
+#define __STAT_WRITE_IOS 4
+// write merges requests number of write I/Os merged with in-queue I/O
+#define __STAT_WRITE_MERGES 5
+// write sectors sectors number of sectors written
+#define __STAT_WRITE_SECTORS 6
+// write ticks milliseconds total wait time for write requests
+#define __STAT_WRITE_TICKS 7
+// in_flight requests number of I/Os currently in flight
+#define __STAT_IN_FLIGHT 8
+// io_ticks milliseconds total time this block device has been active
+#define __STAT_IO_TICKS 9
+// time_in_queue milliseconds total wait time for all requests
+#define __STAT_IN_QUEUE 10
+#define __STAT_NUMBER_FIELD 11
+//
+// read I/Os, write I/Os
+// =====================
+//
+// These values increment when an I/O request completes.
+//
+// read merges, write merges
+// =========================
+//
+// These values increment when an I/O request is merged with an
+// already-queued I/O request.
+//
+// read sectors, write sectors
+// ===========================
+//
+// These values count the number of sectors read from or written to this
+// block device. The "sectors" in question are the standard UNIX 512-byte
+// sectors, not any device- or filesystem-specific block size. The
+// counters are incremented when the I/O completes.
+#define SECTOR_SIZE 512
+//
+// read ticks, write ticks
+// =======================
+//
+// These values count the number of milliseconds that I/O requests have
+// waited on this block device. If there are multiple I/O requests waiting,
+// these values will increase at a rate greater than 1000/second; for
+// example, if 60 read requests wait for an average of 30 ms, the read_ticks
+// field will increase by 60*30 = 1800.
+//
+// in_flight
+// =========
+//
+// This value counts the number of I/O requests that have been issued to
+// the device driver but have not yet completed. It does not include I/O
+// requests that are in the queue but not yet issued to the device driver.
+//
+// io_ticks
+// ========
+//
+// This value counts the number of milliseconds during which the device has
+// had I/O requests queued.
+//
+// time_in_queue
+// =============
+//
+// This value counts the number of milliseconds that I/O requests have waited
+// on this block device. If there are multiple I/O requests waiting, this
+// value will increase as the product of the number of milliseconds times the
+// number of requests waiting (see "read ticks" above for an example).
+#define S_TO_MS 1000
+//
+
static int dump_stat_from_fd(const char *title __unused, const char *path, int fd) {
- unsigned long fields[11], read_perf, write_perf;
+ unsigned long long fields[__STAT_NUMBER_FIELD];
bool z;
char *cp, *buffer = NULL;
size_t i = 0;
@@ -134,7 +214,7 @@
}
z = true;
for (cp = buffer, i = 0; i < (sizeof(fields) / sizeof(fields[0])); ++i) {
- fields[i] = strtol(cp, &cp, 0);
+ fields[i] = strtoull(cp, &cp, 10);
if (fields[i] != 0) {
z = false;
}
@@ -151,17 +231,51 @@
printf("%s: %s\n", path, buffer);
free(buffer);
- read_perf = 0;
- if (fields[3]) {
- read_perf = 512 * fields[2] / fields[3];
- }
- write_perf = 0;
- if (fields[7]) {
- write_perf = 512 * fields[6] / fields[7];
- }
- printf("%s: read: %luKB/s write: %luKB/s\n", path, read_perf, write_perf);
- if ((write_perf > 1) && (write_perf < worst_write_perf)) {
- worst_write_perf = write_perf;
+ if (fields[__STAT_IO_TICKS]) {
+ unsigned long read_perf = 0;
+ unsigned long read_ios = 0;
+ if (fields[__STAT_READ_TICKS]) {
+ unsigned long long divisor = fields[__STAT_READ_TICKS]
+ * fields[__STAT_IO_TICKS];
+ read_perf = ((unsigned long long)SECTOR_SIZE
+ * fields[__STAT_READ_SECTORS]
+ * fields[__STAT_IN_QUEUE] + (divisor >> 1))
+ / divisor;
+ read_ios = ((unsigned long long)S_TO_MS * fields[__STAT_READ_IOS]
+ * fields[__STAT_IN_QUEUE] + (divisor >> 1))
+ / divisor;
+ }
+
+ unsigned long write_perf = 0;
+ unsigned long write_ios = 0;
+ if (fields[__STAT_WRITE_TICKS]) {
+ unsigned long long divisor = fields[__STAT_WRITE_TICKS]
+ * fields[__STAT_IO_TICKS];
+ write_perf = ((unsigned long long)SECTOR_SIZE
+ * fields[__STAT_WRITE_SECTORS]
+ * fields[__STAT_IN_QUEUE] + (divisor >> 1))
+ / divisor;
+ write_ios = ((unsigned long long)S_TO_MS * fields[__STAT_WRITE_IOS]
+ * fields[__STAT_IN_QUEUE] + (divisor >> 1))
+ / divisor;
+ }
+
+ unsigned queue = (fields[__STAT_IN_QUEUE]
+ + (fields[__STAT_IO_TICKS] >> 1))
+ / fields[__STAT_IO_TICKS];
+
+ if (!write_perf && !write_ios) {
+ printf("%s: perf(ios) rd: %luKB/s(%lu/s) q: %u\n",
+ path, read_perf, read_ios, queue);
+ } else {
+ printf("%s: perf(ios) rd: %luKB/s(%lu/s) wr: %luKB/s(%lu/s) q: %u\n",
+ path, read_perf, read_ios, write_perf, write_ios, queue);
+ }
+
+ /* bugreport timeout factor adjustment */
+ if ((write_perf > 1) && (write_perf < worst_write_perf)) {
+ worst_write_perf = write_perf;
+ }
}
return 0;
}