diff mbox series

[net-next,v3,1/2] tcp: add a common helper to debug the underlying issue

Message ID 20241023081452.9151-2-kerneljasonxing@gmail.com (mailing list archive)
State Accepted
Commit 386c2b877b97cde53c6e422f9081ae133492fd05
Delegated to: Netdev Maintainers
Headers show
Series tcp: add tcp_warn_once() common helper | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 12 this patch: 12
netdev/build_tools success Errors and warnings before: 157 (+1) this patch: 157 (+1)
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 15 this patch: 15
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 913 this patch: 913
netdev/checkpatch warning WARNING: line length of 83 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 2 this patch: 2
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-10-23--12-00 (tests: 777)

Commit Message

Jason Xing Oct. 23, 2024, 8:14 a.m. UTC 
From: Jason Xing <kernelxing@tencent.com>

Following the commit c8770db2d544 ("tcp: check skb is non-NULL
in tcp_rto_delta_us()"), we decided to add a helper so that it's
easier to get verbose warning on either cases.

Link: https://lore.kernel.org/all/5632e043-bdba-4d75-bc7e-bf58014492fd@redhat.com/
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Cc: Neal Cardwell <ncardwell@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
---
v3
Link: https://lore.kernel.org/all/f6e70c8d-b9d8-4d15-bb25-69fbec0d138a@kernel.org/
1. add reviewed-by tag (David)

v2
Link: https://lore.kernel.org/all/38811a75-ae98-48e7-96c0-bb1a39a0d722@kernel.org/
1. fix "break quoted strings at a space character" warning (David Ahern)
---
 include/net/tcp.h | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)
diff mbox series

Patch

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 739a9fb83d0c..8b8d94bb1746 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2430,6 +2430,19 @@  void tcp_plb_update_state(const struct sock *sk, struct tcp_plb_state *plb,
 void tcp_plb_check_rehash(struct sock *sk, struct tcp_plb_state *plb);
 void tcp_plb_update_state_upon_rto(struct sock *sk, struct tcp_plb_state *plb);
 
+static inline void tcp_warn_once(const struct sock *sk, bool cond, const char *str)
+{
+	WARN_ONCE(cond,
+		  "%sout:%u sacked:%u lost:%u retrans:%u tlp_high_seq:%u sk_state:%u ca_state:%u advmss:%u mss_cache:%u pmtu:%u\n",
+		  str,
+		  tcp_sk(sk)->packets_out, tcp_sk(sk)->sacked_out,
+		  tcp_sk(sk)->lost_out, tcp_sk(sk)->retrans_out,
+		  tcp_sk(sk)->tlp_high_seq, sk->sk_state,
+		  inet_csk(sk)->icsk_ca_state,
+		  tcp_sk(sk)->advmss, tcp_sk(sk)->mss_cache,
+		  inet_csk(sk)->icsk_pmtu_cookie);
+}
+
 /* At how many usecs into the future should the RTO fire? */
 static inline s64 tcp_rto_delta_us(const struct sock *sk)
 {
@@ -2441,17 +2454,7 @@  static inline s64 tcp_rto_delta_us(const struct sock *sk)
 
 		return rto_time_stamp_us - tcp_sk(sk)->tcp_mstamp;
 	} else {
-		WARN_ONCE(1,
-			"rtx queue empty: "
-			"out:%u sacked:%u lost:%u retrans:%u "
-			"tlp_high_seq:%u sk_state:%u ca_state:%u "
-			"advmss:%u mss_cache:%u pmtu:%u\n",
-			tcp_sk(sk)->packets_out, tcp_sk(sk)->sacked_out,
-			tcp_sk(sk)->lost_out, tcp_sk(sk)->retrans_out,
-			tcp_sk(sk)->tlp_high_seq, sk->sk_state,
-			inet_csk(sk)->icsk_ca_state,
-			tcp_sk(sk)->advmss, tcp_sk(sk)->mss_cache,
-			inet_csk(sk)->icsk_pmtu_cookie);
+		tcp_warn_once(sk, 1, "rtx queue empty: ");
 		return jiffies_to_usecs(rto);
 	}