fix pep8 lint errors in biolatency and biosnoop

Signed-off-by: Alexei Starovoitov <ast@fb.com>
diff --git a/tools/biolatency b/tools/biolatency
index 3b14667..46bebc4 100755
--- a/tools/biolatency
+++ b/tools/biolatency
@@ -1,14 +1,15 @@
 #!/usr/bin/python
+# @lint-avoid-python-3-compatibility-imports
 #
-# biolatency	Summarize block device I/O latency as a histogram.
-#		For Linux, uses BCC, eBPF.
+# biolatency    Summarize block device I/O latency as a histogram.
+#       For Linux, uses BCC, eBPF.
 #
 # USAGE: biolatency [-h] [-T] [-Q] [-m] [-D] [interval] [count]
 #
 # Copyright (c) 2015 Brendan Gregg.
 # Licensed under the Apache License, Version 2.0 (the "License")
 #
-# 20-Sep-2015	Brendan Gregg	Created this.
+# 20-Sep-2015   Brendan Gregg   Created this.
 
 from __future__ import print_function
 from bcc import BPF
@@ -24,21 +25,21 @@
     ./biolatency -D         # show each disk device separately
 """
 parser = argparse.ArgumentParser(
-	description="Summarize block device I/O latency as a histogram",
-	formatter_class=argparse.RawDescriptionHelpFormatter,
-	epilog=examples)
+    description="Summarize block device I/O latency as a histogram",
+    formatter_class=argparse.RawDescriptionHelpFormatter,
+    epilog=examples)
 parser.add_argument("-T", "--timestamp", action="store_true",
-	help="include timestamp on output")
+    help="include timestamp on output")
 parser.add_argument("-Q", "--queued", action="store_true",
-	help="include OS queued time in I/O time")
+    help="include OS queued time in I/O time")
 parser.add_argument("-m", "--milliseconds", action="store_true",
-	help="millisecond histogram")
+    help="millisecond histogram")
 parser.add_argument("-D", "--disks", action="store_true",
-	help="print a histogram per disk device")
+    help="print a histogram per disk device")
 parser.add_argument("interval", nargs="?", default=99999999,
-	help="output interval, in seconds")
+    help="output interval, in seconds")
 parser.add_argument("count", nargs="?", default=99999999,
-	help="number of outputs")
+    help="number of outputs")
 args = parser.parse_args()
 countdown = int(args.count)
 debug = 0
@@ -49,8 +50,8 @@
 #include <linux/blkdev.h>
 
 typedef struct disk_key {
-	char disk[DISK_NAME_LEN];
-	u64 slot;
+    char disk[DISK_NAME_LEN];
+    u64 slot;
 } disk_key_t;
 BPF_HASH(start, struct request *);
 STORAGE
@@ -58,60 +59,60 @@
 // time block I/O
 int trace_req_start(struct pt_regs *ctx, struct request *req)
 {
-	u64 ts = bpf_ktime_get_ns();
-	start.update(&req, &ts);
-	return 0;
+    u64 ts = bpf_ktime_get_ns();
+    start.update(&req, &ts);
+    return 0;
 }
 
 // output
 int trace_req_completion(struct pt_regs *ctx, struct request *req)
 {
-	u64 *tsp, delta;
+    u64 *tsp, delta;
 
-	// fetch timestamp and calculate delta
-	tsp = start.lookup(&req);
-	if (tsp == 0) {
-		return 0;	// missed issue
-	}
-	delta = bpf_ktime_get_ns() - *tsp;
-	FACTOR
+    // fetch timestamp and calculate delta
+    tsp = start.lookup(&req);
+    if (tsp == 0) {
+        return 0;   // missed issue
+    }
+    delta = bpf_ktime_get_ns() - *tsp;
+    FACTOR
 
-	// store as histogram
-	STORE
+    // store as histogram
+    STORE
 
-	start.delete(&req);
-	return 0;
+    start.delete(&req);
+    return 0;
 }
 """
 
 # code substitutions
 if args.milliseconds:
-	bpf_text = bpf_text.replace('FACTOR', 'delta /= 1000000;')
-	label = "msecs"
+    bpf_text = bpf_text.replace('FACTOR', 'delta /= 1000000;')
+    label = "msecs"
 else:
-	bpf_text = bpf_text.replace('FACTOR', 'delta /= 1000;')
-	label = "usecs"
+    bpf_text = bpf_text.replace('FACTOR', 'delta /= 1000;')
+    label = "usecs"
 if args.disks:
-	bpf_text = bpf_text.replace('STORAGE',
-	    'BPF_HISTOGRAM(dist, disk_key_t);')
-	bpf_text = bpf_text.replace('STORE',
-	    'disk_key_t key = {.slot = bpf_log2l(delta)}; ' +
-	    'bpf_probe_read(&key.disk, sizeof(key.disk), ' +
-	    'req->rq_disk->disk_name); dist.increment(key);')
+    bpf_text = bpf_text.replace('STORAGE',
+        'BPF_HISTOGRAM(dist, disk_key_t);')
+    bpf_text = bpf_text.replace('STORE',
+        'disk_key_t key = {.slot = bpf_log2l(delta)}; ' +
+        'bpf_probe_read(&key.disk, sizeof(key.disk), ' +
+        'req->rq_disk->disk_name); dist.increment(key);')
 else:
-	bpf_text = bpf_text.replace('STORAGE', 'BPF_HISTOGRAM(dist);')
-	bpf_text = bpf_text.replace('STORE',
-	    'dist.increment(bpf_log2l(delta));')
+    bpf_text = bpf_text.replace('STORAGE', 'BPF_HISTOGRAM(dist);')
+    bpf_text = bpf_text.replace('STORE',
+        'dist.increment(bpf_log2l(delta));')
 if debug:
-	print(bpf_text)
+    print(bpf_text)
 
 # load BPF program
 b = BPF(text=bpf_text)
 if args.queued:
-	b.attach_kprobe(event="blk_account_io_start", fn_name="trace_req_start")
+    b.attach_kprobe(event="blk_account_io_start", fn_name="trace_req_start")
 else:
-	b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
-	b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
+    b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
+    b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
 b.attach_kprobe(event="blk_account_io_completion",
     fn_name="trace_req_completion")
 
@@ -121,18 +122,18 @@
 exiting = 0 if args.interval else 1
 dist = b.get_table("dist")
 while (1):
-	try:
-		sleep(int(args.interval))
-	except KeyboardInterrupt:
-		exiting=1
+    try:
+        sleep(int(args.interval))
+    except KeyboardInterrupt:
+        exiting = 1
 
-	print()
-	if args.timestamp:
-		print("%-8s\n" % strftime("%H:%M:%S"), end="")
+    print()
+    if args.timestamp:
+        print("%-8s\n" % strftime("%H:%M:%S"), end="")
 
-	dist.print_log2_hist(label, "disk")
-	dist.clear()
+    dist.print_log2_hist(label, "disk")
+    dist.clear()
 
-	countdown -= 1
-	if exiting or countdown == 0:
-		exit()
+    countdown -= 1
+    if exiting or countdown == 0:
+        exit()
diff --git a/tools/biosnoop b/tools/biosnoop
index 633ab61..1d12f9e 100755
--- a/tools/biosnoop
+++ b/tools/biosnoop
@@ -1,7 +1,8 @@
 #!/usr/bin/python
+# @lint-avoid-python-3-compatibility-imports
 #
-# biosnoop	Trace block device I/O and print details including issuing PID.
-#		For Linux, uses BCC, eBPF.
+# biosnoop  Trace block device I/O and print details including issuing PID.
+#       For Linux, uses BCC, eBPF.
 #
 # This uses in-kernel eBPF maps to cache process details (PID and comm) by I/O
 # request, as well as a starting timestamp for calculating I/O latency.
@@ -9,7 +10,7 @@
 # Copyright (c) 2015 Brendan Gregg.
 # Licensed under the Apache License, Version 2.0 (the "License")
 #
-# 16-Sep-2015	Brendan Gregg	Created this.
+# 16-Sep-2015   Brendan Gregg   Created this.
 
 from __future__ import print_function
 from bcc import BPF
@@ -20,7 +21,7 @@
 #include <linux/blkdev.h>
 
 struct val_t {
-	char name[TASK_COMM_LEN];
+    char name[TASK_COMM_LEN];
 };
 
 BPF_HASH(start, struct request *);
@@ -30,74 +31,74 @@
 // cache PID and comm by-req
 int trace_pid_start(struct pt_regs *ctx, struct request *req)
 {
-	u32 pid;
-	struct val_t val = {};
+    u32 pid;
+    struct val_t val = {};
 
-	pid = bpf_get_current_pid_tgid();
-	pidbyreq.update(&req, &pid);
-	if (bpf_get_current_comm(&val.name, sizeof(val.name)) == 0) {
-		commbyreq.update(&req, &val);
-	}
+    pid = bpf_get_current_pid_tgid();
+    pidbyreq.update(&req, &pid);
+    if (bpf_get_current_comm(&val.name, sizeof(val.name)) == 0) {
+        commbyreq.update(&req, &val);
+    }
 
-	return 0;
+    return 0;
 }
 
 // time block I/O
 int trace_req_start(struct pt_regs *ctx, struct request *req)
 {
-	u64 ts;
+    u64 ts;
 
-	ts = bpf_ktime_get_ns();
-	start.update(&req, &ts);
+    ts = bpf_ktime_get_ns();
+    start.update(&req, &ts);
 
-	return 0;
+    return 0;
 }
 
 // output
 int trace_req_completion(struct pt_regs *ctx, struct request *req)
 {
-	u64 *tsp, delta;
-	u32 *pidp = 0;
-	struct val_t *valp;
+    u64 *tsp, delta;
+    u32 *pidp = 0;
+    struct val_t *valp;
 
-	// fetch timestamp and calculate delta
-	tsp = start.lookup(&req);
-	if (tsp == 0) {
-		// missed tracing issue
-		return 0;
-	}
-	delta = bpf_ktime_get_ns() - *tsp;
+    // fetch timestamp and calculate delta
+    tsp = start.lookup(&req);
+    if (tsp == 0) {
+        // missed tracing issue
+        return 0;
+    }
+    delta = bpf_ktime_get_ns() - *tsp;
 
-	//
-	// Fetch and output issuing pid and comm.
-	// As bpf_trace_prink() is limited to a maximum of 1 string and 2
-	// integers, we'll use more than one to output the data.
-	//
-	valp = commbyreq.lookup(&req);
-	pidp = pidbyreq.lookup(&req);
-	if (pidp == 0 || valp == 0) {
-		bpf_trace_printk("0 0 ? %d\\n", req->__data_len);
-	} else {
-		bpf_trace_printk("0 %d %s %d\\n", *pidp, valp->name,
-		    req->__data_len);
-	}
+    //
+    // Fetch and output issuing pid and comm.
+    // As bpf_trace_prink() is limited to a maximum of 1 string and 2
+    // integers, we'll use more than one to output the data.
+    //
+    valp = commbyreq.lookup(&req);
+    pidp = pidbyreq.lookup(&req);
+    if (pidp == 0 || valp == 0) {
+        bpf_trace_printk("0 0 ? %d\\n", req->__data_len);
+    } else {
+        bpf_trace_printk("0 %d %s %d\\n", *pidp, valp->name,
+            req->__data_len);
+    }
 
-	// output remaining details
-	if (req->cmd_flags & REQ_WRITE) {
-		bpf_trace_printk("1 W %s %d %d ?\\n", req->rq_disk->disk_name,
-		    req->__sector, delta / 1000);
-	} else {
-		bpf_trace_printk("1 R %s %d %d ?\\n", req->rq_disk->disk_name,
-		    req->__sector, delta / 1000);
-	}
+    // output remaining details
+    if (req->cmd_flags & REQ_WRITE) {
+        bpf_trace_printk("1 W %s %d %d ?\\n", req->rq_disk->disk_name,
+            req->__sector, delta / 1000);
+    } else {
+        bpf_trace_printk("1 R %s %d %d ?\\n", req->rq_disk->disk_name,
+            req->__sector, delta / 1000);
+    }
 
-	start.delete(&req);
-	pidbyreq.delete(&req);
-	commbyreq.delete(&req);
+    start.delete(&req);
+    pidbyreq.delete(&req);
+    commbyreq.delete(&req);
 
-	return 0;
+    return 0;
 }
-""")
+""", debug=0)
 b.attach_kprobe(event="blk_account_io_start", fn_name="trace_pid_start")
 b.attach_kprobe(event="blk_start_request", fn_name="trace_req_start")
 b.attach_kprobe(event="blk_mq_start_request", fn_name="trace_req_start")
@@ -112,21 +113,21 @@
 
 # format output
 while 1:
-	(task, pid, cpu, flags, ts, msg) = b.trace_fields()
-	args = msg.split(" ")
+    (task, pid, cpu, flags, ts, msg) = b.trace_fields()
+    args = msg.split(" ")
 
-	if start_ts == 0:
-		start_ts = ts
+    if start_ts == 0:
+        start_ts = ts
 
-	if args[0] == "0":
-		(real_pid, real_comm, bytes_s) = (args[1], args[2], args[3])
-		continue
-	else:
-		(type_s, disk_s, sector_s, us_s) = (args[1], args[2], args[3],
-		    args[4])
+    if args[0] == "0":
+        (real_pid, real_comm, bytes_s) = (args[1], args[2], args[3])
+        continue
+    else:
+        (type_s, disk_s, sector_s, us_s) = (args[1], args[2], args[3],
+            args[4])
 
-	ms = float(int(us_s, 10)) / 1000
+    ms = float(int(us_s, 10)) / 1000
 
-	print("%-14.9f %-14.14s %-6s %-7s %-2s %-9s %-7s %7.2f" % (
-	    ts - start_ts, real_comm, real_pid, disk_s, type_s, sector_s,
-	    bytes_s, ms))
+    print("%-14.9f %-14.14s %-6s %-7s %-2s %-9s %-7s %7.2f" % (
+        ts - start_ts, real_comm, real_pid, disk_s, type_s, sector_s,
+        bytes_s, ms))
diff --git a/tools/biosnoop_example.txt b/tools/biosnoop_example.txt
index 7d02d0d..b5cee7f 100644
--- a/tools/biosnoop_example.txt
+++ b/tools/biosnoop_example.txt
@@ -36,11 +36,11 @@
 avg-cpu:  %user   %nice %system %iowait  %steal   %idle
            0.12    0.00    0.12    0.00    0.00   99.75
 
-Device:         rrqm/s   wrqm/s     r/s     w/s    rkB/s    wkB/s avgrq-sz avgqu-sz   await r_await w_await  svctm  %util
-xvda              0.00     0.00    0.00    4.00     0.00    16.00     8.00     0.00    0.00    0.00    0.00   0.00   0.00
-xvdb              0.00     0.00    0.00    0.00     0.00     0.00     0.00     0.00    0.00    0.00    0.00   0.00   0.00
-xvdc              0.00     0.00    0.00    0.00     0.00     0.00     0.00     0.00    0.00    0.00    0.00   0.00   0.00
-md0               0.00     0.00    0.00    0.00     0.00     0.00     0.00     0.00    0.00    0.00    0.00   0.00   0.00
+Device: rrqm/s  wrqm/s    r/s    w/s  rkB/s  wkB/s  await  svctm  %util
+xvda      0.00    0.00   0.00   4.00   0.00  16.00   0.00   0.00   0.00
+xvdb      0.00    0.00   0.00   0.00   0.00   0.00   0.00   0.00   0.00
+xvdc      0.00    0.00   0.00   0.00   0.00   0.00   0.00   0.00   0.00
+md0       0.00    0.00   0.00   0.00   0.00   0.00   0.00   0.00   0.00
 
 There are 4 write IOPS.