Add speed testing script

utils/speed_tester.py

@@ -0,0 +1,85 @@
+#!/usr/bin/python3
+
+'''This script executes random-sized reads and writes to one or more block devices to test them.
+It will destroy the contents of the block device.'''
+
+import sys
+import os
+import mmap
+import random
+import time
+
+class BlockDevice:
+    def __init__(self, path, sectorsize = 512):
+        self.path = path
+        self.dev = os.fdopen(os.open(path, os.O_RDWR | os.O_DIRECT | os.O_SYNC), "rb+", 0)
+        self.sectorsize = sectorsize
+
+    def write_block(self, first_sector, sector_count, seed):
+        rnd = random.Random(seed)
+        buffer = mmap.mmap(-1, sector_count * self.sectorsize)
+        buffer.write(rnd.randbytes(sector_count * self.sectorsize))
+        
+        start = time.time()
+        self.dev.seek(first_sector * self.sectorsize)
+        self.dev.write(buffer)
+        elapsed = time.time() - start
+        speed = sector_count * self.sectorsize / elapsed / 1e6
+
+        print("Wrote  %16s, %8d, %8d, %8d, %8.3f MB/s" % (self.path, first_sector, sector_count, seed, speed))
+        return speed
+
+    def verify_block(self, first_sector, sector_count, seed):
+        rnd = random.Random(seed)
+        buffer = mmap.mmap(-1, sector_count * self.sectorsize)
+
+        start = time.time()
+        self.dev.seek(first_sector * self.sectorsize)
+        self.dev.readinto(buffer)
+        elapsed = time.time() - start
+        speed = sector_count * self.sectorsize / elapsed / 1e6
+
+        print("Verify %16s, %8d, %8d, %8d, %8.3f MB/s" % (self.path, first_sector, sector_count, seed, speed))
+
+        buffer.seek(0)
+        actual = buffer.read(sector_count * self.sectorsize)
+        expected = rnd.randbytes(sector_count * self.sectorsize)
+        if expected != actual:
+            print("Compare error, device = %s, sectorsize = %d, first_sector = %d, sector_count = %d, seed = %d"
+                % (self.path, self.sectorsize, first_sector, sector_count, seed))
+            fname = "%d" % time.time()
+            open(fname + ".expected", "wb").write(expected)
+            open(fname + ".actual", "wb").write(actual)
+            print("Saved data to %s.expected/actual" % fname)
+            raise Exception("Compare error")
+        
+        return speed
+
+if __name__ == "__main__":
+    blockdev = BlockDevice(sys.argv[1])
+    
+    seed = 1
+    
+    results = '# ReqSize(B)  RdSpeed(MB/s)  WrSpeed(MB/s)\n'
+    for i in range(12):
+        seed += 1
+        seccount = 2**i
+        wr_speeds = []
+        rd_speeds = []
+        samplecount = 8
+        for i in range(samplecount):
+            wr_speeds.append(blockdev.write_block(0, seccount, seed))
+            time.sleep(0.2)
+            rd_speeds.append(blockdev.verify_block(0, seccount, seed))
+            time.sleep(0.2)
+
+        # Get median
+        wr_speeds.sort()
+        rd_speeds.sort()
+        wr_speed = wr_speeds[samplecount//2]
+        rd_speed = rd_speeds[samplecount//2]
+        
+        results += '%8d %8.3f %8.3f\n' % (seccount * 512, rd_speed, wr_speed)
+    
+    print(results)
+