bcc/tools: Add biopattern.py to identify disk access patterns
diff --git a/tools/biopattern.py b/tools/biopattern.py
new file mode 100755
index 0000000..9bfc077
--- /dev/null
+++ b/tools/biopattern.py
@@ -0,0 +1,140 @@
+#!/usr/bin/python
+# @lint-avoid-python-3-compatibility-imports
+#
+# biopattern - Identify random/sequential disk access patterns.
+# For Linux, uses BCC, eBPF.
+#
+# Copyright (c) 2022 Rocky Xing.
+# Licensed under the Apache License, Version 2.0 (the "License")
+#
+# 21-Feb-2022 Rocky Xing Created this.
+
+from __future__ import print_function
+from bcc import BPF
+from time import sleep, strftime
+import argparse
+import os
+
+examples = """examples:
+ ./biopattern # show block device I/O pattern.
+ ./biopattern 1 10 # print 1 second summaries, 10 times
+ ./biopattern -d sdb # show sdb only
+"""
+parser = argparse.ArgumentParser(
+ description="Show block device I/O pattern.",
+ formatter_class=argparse.RawDescriptionHelpFormatter,
+ epilog=examples)
+parser.add_argument("-d", "--disk", type=str,
+ help="Trace this disk only")
+parser.add_argument("interval", nargs="?", default=99999999,
+ help="Output interval in seconds")
+parser.add_argument("count", nargs="?", default=99999999,
+ help="Number of outputs")
+args = parser.parse_args()
+countdown = int(args.count)
+
+bpf_text="""
+struct counter {
+ u64 last_sector;
+ u64 bytes;
+ u32 sequential;
+ u32 random;
+};
+
+BPF_HASH(counters, u32, struct counter);
+
+TRACEPOINT_PROBE(block, block_rq_complete)
+{
+ struct counter *counterp;
+ struct counter zero = {};
+ u32 dev = args->dev;
+ u64 sector = args->sector;
+ u32 nr_sector = args->nr_sector;
+
+ DISK_FILTER
+
+ counterp = counters.lookup_or_try_init(&dev, &zero);
+ if (counterp == 0) {
+ return 0;
+ }
+
+ if (counterp->last_sector) {
+ if (counterp->last_sector == sector) {
+ __sync_fetch_and_add(&counterp->sequential, 1);
+ } else {
+ __sync_fetch_and_add(&counterp->random, 1);
+ }
+ __sync_fetch_and_add(&counterp->bytes, nr_sector * 512);
+ }
+ counterp->last_sector = sector + nr_sector;
+
+ return 0;
+}
+"""
+
+dev_minor_bits = 20
+
+def mkdev(major, minor):
+ return (major << dev_minor_bits) | minor
+
+
+partitions = {}
+
+with open("/proc/partitions", 'r') as f:
+ lines = f.readlines()
+ for line in lines[2:]:
+ words = line.strip().split()
+ major = int(words[0])
+ minor = int(words[1])
+ part_name = words[3]
+ partitions[mkdev(major, minor)] = part_name
+
+if args.disk is not None:
+ disk_path = os.path.join('/dev', args.disk)
+ if os.path.exists(disk_path) == False:
+ print("no such disk '%s'" % args.disk)
+ exit(1)
+
+ stat_info = os.stat(disk_path)
+ major = os.major(stat_info.st_rdev)
+ minor = os.minor(stat_info.st_rdev)
+ bpf_text = bpf_text.replace('DISK_FILTER',
+ 'if (dev != %s) { return 0; }' % mkdev(major, minor))
+else:
+ bpf_text = bpf_text.replace('DISK_FILTER', '')
+
+b = BPF(text=bpf_text)
+
+exiting = 0 if args.interval else 1
+counters = b.get_table("counters")
+
+print("%-9s %-7s %5s %5s %8s %10s" %
+ ("TIME", "DISK", "%RND", "%SEQ", "COUNT", "KBYTES"))
+
+while True:
+ try:
+ sleep(int(args.interval))
+ except KeyboardInterrupt:
+ exiting = 1
+
+ for k, v in counters.items():
+ total = v.random + v.sequential
+ if total == 0:
+ continue
+
+ part_name = partitions.get(k.value, "Unknown")
+
+ print("%-9s %-7s %5d %5d %8d %10d" % (
+ strftime("%H:%M:%S"),
+ part_name,
+ v.random * 100 / total,
+ v.sequential * 100 / total,
+ total,
+ v.bytes / 1024))
+
+ counters.clear()
+
+ countdown -= 1
+ if exiting or countdown == 0:
+ exit()
+