bcc/tools: Add cpu filter (-c CPU) for softirqs & hardirqs
diff --git a/tools/hardirqs.py b/tools/hardirqs.py
index 0eedddd..4e373d9 100755
--- a/tools/hardirqs.py
+++ b/tools/hardirqs.py
@@ -4,7 +4,7 @@
# hardirqs Summarize hard IRQ (interrupt) event time.
# For Linux, uses BCC, eBPF.
#
-# USAGE: hardirqs [-h] [-T] [-N] [-C] [-d] [interval] [outputs]
+# USAGE: hardirqs [-h] [-T] [-N] [-C] [-d] [-c CPU] [interval] [outputs]
#
# Thanks Amer Ather for help understanding irq behavior.
#
@@ -13,6 +13,7 @@
#
# 19-Oct-2015 Brendan Gregg Created this.
# 22-May-2021 Hengqi Chen Migrated to kernel tracepoints.
+# 07-Mar-2022 Rocky Xing Added CPU filter support.
from __future__ import print_function
from bcc import BPF
@@ -25,6 +26,7 @@
./hardirqs -d # show hard irq event time as histograms
./hardirqs 1 10 # print 1 second summaries, 10 times
./hardirqs -NT 1 # 1s summaries, nanoseconds, and timestamps
+ ./hardirqs -c 1 # sum hard irq event time on CPU 1 only
"""
parser = argparse.ArgumentParser(
description="Summarize hard irq event time as histograms",
@@ -38,6 +40,8 @@
help="show event counts instead of timing")
parser.add_argument("-d", "--dist", action="store_true",
help="show distributions as histograms")
+parser.add_argument("-c", "--cpu", type=int,
+ help="trace this CPU only")
parser.add_argument("interval", nargs="?", default=99999999,
help="output interval, in seconds")
parser.add_argument("outputs", nargs="?", default=99999999,
@@ -94,9 +98,12 @@
{
struct entry_key key = {};
irq_name_t name = {};
+ u32 cpu = bpf_get_smp_processor_id();
+
+ FILTER_CPU
key.tid = bpf_get_current_pid_tgid();
- key.cpu_id = bpf_get_smp_processor_id();
+ key.cpu_id = cpu;
TP_DATA_LOC_READ_STR(&name.name, name, sizeof(name));
irqnames.update(&key, &name);
@@ -106,9 +113,12 @@
TRACEPOINT_PROBE(irq, irq_handler_exit)
{
struct entry_key key = {};
+ u32 cpu = bpf_get_smp_processor_id();
+
+ FILTER_CPU
key.tid = bpf_get_current_pid_tgid();
- key.cpu_id = bpf_get_smp_processor_id();
+ key.cpu_id = cpu;
// check ret value of irq handler is not IRQ_NONE to make sure
// the current event belong to this irq handler
@@ -137,9 +147,12 @@
u64 ts = bpf_ktime_get_ns();
irq_name_t name = {};
struct entry_key key = {};
+ u32 cpu = bpf_get_smp_processor_id();
+
+ FILTER_CPU
key.tid = bpf_get_current_pid_tgid();
- key.cpu_id = bpf_get_smp_processor_id();
+ key.cpu_id = cpu;
TP_DATA_LOC_READ_STR(&name.name, name, sizeof(name));
irqnames.update(&key, &name);
@@ -152,9 +165,10 @@
u64 *tsp, delta;
irq_name_t *namep;
struct entry_key key = {};
+ u32 cpu = bpf_get_smp_processor_id();
key.tid = bpf_get_current_pid_tgid();
- key.cpu_id = bpf_get_smp_processor_id();
+ key.cpu_id = cpu;
// check ret value of irq handler is not IRQ_NONE to make sure
// the current event belong to this irq handler
@@ -195,6 +209,11 @@
'irq_key_t key = {.slot = 0 /* ignore */};' +
'bpf_probe_read_kernel(&key.name, sizeof(key.name), name);' +
'dist.atomic_increment(key, delta);')
+if args.cpu is not None:
+ bpf_text = bpf_text.replace('FILTER_CPU',
+ 'if (cpu != %d) { return 0; }' % int(args.cpu))
+else:
+ bpf_text = bpf_text.replace('FILTER_CPU', '')
if debug or args.ebpf:
print(bpf_text)
if args.ebpf: