Commit d6d4ff33 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

tcp: inline tcp_chrono_start() 



tcp_chrono_start() is small enough, and used in TCP sendmsg()
fast path (from tcp_skb_entail()).

Note clang is already inlining it from functions in tcp_output.c.

Inlining it improves performance and reduces bloat :

$ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
add/remove: 0/2 grow/shrink: 1/0 up/down: 1/-84 (-83)
Function                                     old     new   delta
tcp_skb_entail                               280     281      +1
__pfx_tcp_chrono_start                        16       -     -16
tcp_chrono_start                              68       -     -68
Total: Before=25192434, After=25192351, chg -0.00%

Note that tcp_chrono_stop() is too big.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarNeal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20260308123549.2924460-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 4b78c9cb

include/net/tcp.h

+24 −1
Original line number Diff line number Diff line
@@ -2159,7 +2159,30 @@ enum tcp_chrono { 
	__TCP_CHRONO_MAX,

};



void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type);

static inline void tcp_chrono_set(struct tcp_sock *tp, const enum tcp_chrono new)

{

	const u32 now = tcp_jiffies32;

	enum tcp_chrono old = tp->chrono_type;



	if (old > TCP_CHRONO_UNSPEC)

		tp->chrono_stat[old - 1] += now - tp->chrono_start;

	tp->chrono_start = now;

	tp->chrono_type = new;

}



static inline void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type)

{

	struct tcp_sock *tp = tcp_sk(sk);



	/* If there are multiple conditions worthy of tracking in a

	 * chronograph then the highest priority enum takes precedence

	 * over the other conditions. So that if something "more interesting"

	 * starts happening, stop the previous chrono and start a new one.

	 */

	if (type > tp->chrono_type)

		tcp_chrono_set(tp, type);

}



void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type);



/* This helper is needed, because skb->tcp_tsorted_anchor uses

net/ipv4/tcp_output.c

+0 −24
Original line number Diff line number Diff line
@@ -2903,30 +2903,6 @@ static bool tcp_small_queue_check(struct sock *sk, const struct sk_buff *skb, 
	return false;

}



static void tcp_chrono_set(struct tcp_sock *tp, const enum tcp_chrono new)

{

	const u32 now = tcp_jiffies32;

	enum tcp_chrono old = tp->chrono_type;



	if (old > TCP_CHRONO_UNSPEC)

		tp->chrono_stat[old - 1] += now - tp->chrono_start;

	tp->chrono_start = now;

	tp->chrono_type = new;

}



void tcp_chrono_start(struct sock *sk, const enum tcp_chrono type)

{

	struct tcp_sock *tp = tcp_sk(sk);



	/* If there are multiple conditions worthy of tracking in a

	 * chronograph then the highest priority enum takes precedence

	 * over the other conditions. So that if something "more interesting"

	 * starts happening, stop the previous chrono and start a new one.

	 */

	if (type > tp->chrono_type)

		tcp_chrono_set(tp, type);

}



void tcp_chrono_stop(struct sock *sk, const enum tcp_chrono type)

{

	struct tcp_sock *tp = tcp_sk(sk);