FM / examples

/usr/share/doc/bpftrace/examples

Name	Size	Mode	Actions
bashreadline_example.txt	722	0644	edit dl rm
biolatency_example.txt	1790	0644	edit dl rm
biosnoop_example.txt	2056	0644	edit dl rm
biostacks_example.txt	1914	0644	edit dl rm
bitesize_example.txt	3003	0644	edit dl rm
capable_example.txt	2659	0644	edit dl rm
cpuwalk_example.txt	4919	0644	edit dl rm
dcsnoop_example.txt	4612	0644	edit dl rm
execsnoop_example.txt	1535	0644	edit dl rm
gethostlatency_example.txt	923	0644	edit dl rm
killsnoop_example.txt	846	0644	edit dl rm
loads_example.txt	864	0644	edit dl rm
mdflush_example.txt	1866	0644	edit dl rm
naptime_example.txt	844	0644	edit dl rm
oomkill_example.txt	1668	0644	edit dl rm
opensnoop_example.txt	2528	0644	edit dl rm
pidpersec_example.txt	1504	0644	edit dl rm
runqlat_example.txt	8632	0644	edit dl rm
runqlen_example.txt	980	0644	edit dl rm
setuids_example.txt	2441	0644	edit dl rm
ssllatency_example.txt	4510	0644	edit dl rm
sslsnoop_example.txt	1916	0644	edit dl rm
statsnoop_example.txt	2738	0644	edit dl rm
swapin_example.txt	549	0644	edit dl rm
syncsnoop_example.txt	541	0644	edit dl rm
syscount_example.txt	1144	0644	edit dl rm
tcpaccept_example.txt	1350	0644	edit dl rm
tcpconnect_example.txt	1085	0644	edit dl rm
tcpdrop_example.txt	1256	0644	edit dl rm
tcplife_example.txt	1597	0644	edit dl rm
tcpretrans_example.txt	1153	0644	edit dl rm
tcpsynbl_example.txt	940	0644	edit dl rm
threadsnoop_example.txt	1182	0644	edit dl rm
undump_example.txt	680	0644	edit dl rm
vfscount_example.txt	1199	0644	edit dl rm
vfsstat_example.txt	929	0644	edit dl rm
writeback_example.txt	1962	0644	edit dl rm
xfsdist_example.txt	3419	0644	edit dl rm

Edit: /usr/share/doc/bpftrace/examples/tcpdrop_example.txt (1256B)

Demonstrations of tcpdrop, the Linux bpftrace/eBPF version.

tcpdrop prints details of TCP packets or segments that were dropped by the
kernel, including the kernel stack trace that led to the drop:

# ./tcpdrop.bt
TIME     PID      COMM             SADDR:SPORT           DADDR:DPORT           STATE
00:39:21 0        swapper/2         10.231.244.31:3306     10.229.20.82:50552  ESTABLISHE
	tcp_drop+0x1
	tcp_v4_do_rcv+0x135
	tcp_v4_rcv+0x9c7
	ip_local_deliver_finish+0x62
	ip_local_deliver+0x6f
	ip_rcv_finish+0x129
	ip_rcv+0x28f
	__netif_receive_skb_core+0x432
	__netif_receive_skb+0x18
	netif_receive_skb_internal+0x37
	napi_gro_receive+0xc5
	ena_clean_rx_irq+0x3c3
	ena_io_poll+0x33f
	net_rx_action+0x140
	__softirqentry_text_start+0xdf
	irq_exit+0xb6
	do_IRQ+0x82
	ret_from_intr+0x0
	native_safe_halt+0x6
	default_idle+0x20
	arch_cpu_idle+0x15
	default_idle_call+0x23
	do_idle+0x17f
	cpu_startup_entry+0x73
	rest_init+0xae
	start_kernel+0x4dc
	x86_64_start_reservations+0x24
	x86_64_start_kernel+0x74
	secondary_startup_64+0xa5
[...]

The last column shows the state of the TCP session.

This tool is useful for debugging high rates of drops, which can cause the
remote end to do timer-based retransmits, hurting performance.

USAGE:

# ./tcpdrop.bt

cmd: