From: Eric Dumazet <edumazet@google.com>
To: "David S . Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Paolo Abeni <pabeni@redhat.com>
Cc: Simon Horman <horms@kernel.org>,
Kuniyuki Iwashima <kuniyu@google.com>,
Willem de Bruijn <willemb@google.com>,
netdev@vger.kernel.org, eric.dumazet@gmail.com,
Eric Dumazet <edumazet@google.com>
Subject: [PATCH net-next] net: use ktime_t in struct scm_timestamping_internal
Date: Wed, 4 Mar 2026 01:27:47 +0000 [thread overview]
Message-ID: <20260304012747.881644-1-edumazet@google.com> (raw)
Instead of using struct timespec64 in scm_timestamping_internal,
use ktime_t, saving 24 bytes in kernel stack.
This makes tcp_update_recv_tstamps() small enough to be inlined.
The ktime_t -> timespec64 conversions happen after socket lock
has been released in tcp_recvmsg(), and only if the application
requested them.
$ scripts/bloat-o-meter -t vmlinux.0 vmlinux
add/remove: 0/2 grow/shrink: 5/4 up/down: 146/-277 (-131)
Function old new delta
tcp_zerocopy_receive 2383 2425 +42
mptcp_recvmsg 1565 1607 +42
tcp_recvmsg_locked 3797 3823 +26
put_cmsg_scm_timestamping64 131 149 +18
put_cmsg_scm_timestamping 131 149 +18
__pfx_tcp_update_recv_tstamps 16 - -16
do_tcp_getsockopt 4024 4006 -18
tcp_recv_timestamp 474 430 -44
tcp_zc_handle_leftover 417 371 -46
__sock_recv_timestamp 1087 1031 -56
tcp_update_recv_tstamps 97 - -97
Total: Before=25223788, After=25223657, chg -0.00%
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
include/linux/socket.h | 2 +-
include/net/tcp.h | 11 ++++++--
net/core/scm.c | 12 ++++++---
net/ipv4/tcp.c | 61 +++++++++++++++---------------------------
net/socket.c | 23 ++++++++--------
5 files changed, 51 insertions(+), 58 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index ec715ad4bf25f5f759d2cab3c6b796fed84df932..ec4a0a0257939a5363c55bed3ccb20182965b2e3 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -415,7 +415,7 @@ struct __kernel_timespec;
struct old_timespec32;
struct scm_timestamping_internal {
- struct timespec64 ts[3];
+ ktime_t ts[3];
};
extern void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_internal *tss);
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9cf8785ef0b42460a2389b4aa75570b3aa31cbb4..fea6081cf6c798fe5f3f3b3ab3335619d7324f6e 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -503,8 +503,15 @@ int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int flags);
int tcp_set_rcvlowat(struct sock *sk, int val);
int tcp_set_window_clamp(struct sock *sk, int val);
-void tcp_update_recv_tstamps(struct sk_buff *skb,
- struct scm_timestamping_internal *tss);
+
+static inline void
+tcp_update_recv_tstamps(struct sk_buff *skb,
+ struct scm_timestamping_internal *tss)
+{
+ tss->ts[0] = skb->tstamp;
+ tss->ts[2] = skb_hwtstamps(skb)->hwtstamp;
+}
+
void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
struct scm_timestamping_internal *tss);
void tcp_data_ready(struct sock *sk);
diff --git a/net/core/scm.c b/net/core/scm.c
index a29aa8fb8065665f8a8f2255ec3e55df973a6b0a..eec13f50ecaf6fa7caf9316bf17ab401d98d0efc 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -318,8 +318,10 @@ void put_cmsg_scm_timestamping64(struct msghdr *msg, struct scm_timestamping_int
int i;
for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
- tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
- tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
+ struct timespec64 tv = ktime_to_timespec64(tss_internal->ts[i]);
+
+ tss.ts[i].tv_sec = tv.tv_sec;
+ tss.ts[i].tv_nsec = tv.tv_nsec;
}
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_NEW, sizeof(tss), &tss);
@@ -332,8 +334,10 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter
int i;
for (i = 0; i < ARRAY_SIZE(tss.ts); i++) {
- tss.ts[i].tv_sec = tss_internal->ts[i].tv_sec;
- tss.ts[i].tv_nsec = tss_internal->ts[i].tv_nsec;
+ struct timespec64 tv = ktime_to_timespec64(tss_internal->ts[i]);
+
+ tss.ts[i].tv_sec = tv.tv_sec;
+ tss.ts[i].tv_nsec = tv.tv_nsec;
}
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPING_OLD, sizeof(tss), &tss);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 1790d2fa75ade77cda8d0a593e689ea4432734dd..3d77d90c14fe13777d17563e17596066c44c66bd 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1871,20 +1871,6 @@ int tcp_set_rcvlowat(struct sock *sk, int val)
}
EXPORT_IPV6_MOD(tcp_set_rcvlowat);
-void tcp_update_recv_tstamps(struct sk_buff *skb,
- struct scm_timestamping_internal *tss)
-{
- if (skb->tstamp)
- tss->ts[0] = ktime_to_timespec64(skb->tstamp);
- else
- tss->ts[0] = (struct timespec64) {0};
-
- if (skb_hwtstamps(skb)->hwtstamp)
- tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
- else
- tss->ts[2] = (struct timespec64) {0};
-}
-
#ifdef CONFIG_MMU
static const struct vm_operations_struct tcp_vm_ops = {
};
@@ -2376,22 +2362,23 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
{
int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
u32 tsflags = READ_ONCE(sk->sk_tsflags);
- bool has_timestamping = false;
- if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
+ if (tss->ts[0]) {
if (sock_flag(sk, SOCK_RCVTSTAMP)) {
+ struct timespec64 tv = ktime_to_timespec64(tss->ts[0]);
+
if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
if (new_tstamp) {
struct __kernel_timespec kts = {
- .tv_sec = tss->ts[0].tv_sec,
- .tv_nsec = tss->ts[0].tv_nsec,
+ .tv_sec = tv.tv_sec,
+ .tv_nsec = tv.tv_nsec,
};
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
sizeof(kts), &kts);
} else {
struct __kernel_old_timespec ts_old = {
- .tv_sec = tss->ts[0].tv_sec,
- .tv_nsec = tss->ts[0].tv_nsec,
+ .tv_sec = tv.tv_sec,
+ .tv_nsec = tv.tv_nsec,
};
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
sizeof(ts_old), &ts_old);
@@ -2399,41 +2386,37 @@ void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
} else {
if (new_tstamp) {
struct __kernel_sock_timeval stv = {
- .tv_sec = tss->ts[0].tv_sec,
- .tv_usec = tss->ts[0].tv_nsec / 1000,
+ .tv_sec = tv.tv_sec,
+ .tv_usec = tv.tv_nsec / 1000,
};
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
sizeof(stv), &stv);
} else {
- struct __kernel_old_timeval tv = {
- .tv_sec = tss->ts[0].tv_sec,
- .tv_usec = tss->ts[0].tv_nsec / 1000,
+ struct __kernel_old_timeval otv = {
+ .tv_sec = tv.tv_sec,
+ .tv_usec = tv.tv_nsec / 1000,
};
put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
- sizeof(tv), &tv);
+ sizeof(otv), &otv);
}
}
}
- if (tsflags & SOF_TIMESTAMPING_SOFTWARE &&
+ if (!(tsflags & SOF_TIMESTAMPING_SOFTWARE &&
(tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
- !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)))
- has_timestamping = true;
- else
- tss->ts[0] = (struct timespec64) {0};
+ !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))))
+ tss->ts[0] = 0;
}
- if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
- if (tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
+ if (tss->ts[2]) {
+ if (!(tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
(tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
- !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)))
- has_timestamping = true;
- else
- tss->ts[2] = (struct timespec64) {0};
+ !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))))
+ tss->ts[2] = 0;
}
- if (has_timestamping) {
- tss->ts[1] = (struct timespec64) {0};
+ if (tss->ts[0] | tss->ts[2]) {
+ tss->ts[1] = 0;
if (sock_flag(sk, SOCK_TSTAMP_NEW))
put_cmsg_scm_timestamping64(msg, tss);
else
diff --git a/net/socket.c b/net/socket.c
index 05952188127f5bce41494e99e86418249e9022f2..68829d09bcf1468dee49864c5e4ea52362c3c6c7 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -912,11 +912,10 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
{
int need_software_tstamp = sock_flag(sk, SOCK_RCVTSTAMP);
int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
- struct scm_timestamping_internal tss;
- int empty = 1, false_tstamp = 0;
struct skb_shared_hwtstamps *shhwtstamps =
skb_hwtstamps(skb);
- int if_index;
+ struct scm_timestamping_internal tss;
+ int if_index, false_tstamp = 0;
ktime_t hwtstamp;
u32 tsflags;
@@ -961,12 +960,12 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
memset(&tss, 0, sizeof(tss));
tsflags = READ_ONCE(sk->sk_tsflags);
- if ((tsflags & SOF_TIMESTAMPING_SOFTWARE &&
- (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
- skb_is_err_queue(skb) ||
- !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER))) &&
- ktime_to_timespec64_cond(skb->tstamp, tss.ts + 0))
- empty = 0;
+ if (tsflags & SOF_TIMESTAMPING_SOFTWARE &&
+ (tsflags & SOF_TIMESTAMPING_RX_SOFTWARE ||
+ skb_is_err_queue(skb) ||
+ !(tsflags & SOF_TIMESTAMPING_OPT_RX_FILTER)))
+ tss.ts[0] = skb->tstamp;
+
if (shhwtstamps &&
(tsflags & SOF_TIMESTAMPING_RAW_HARDWARE &&
(tsflags & SOF_TIMESTAMPING_RX_HARDWARE ||
@@ -983,15 +982,15 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk,
hwtstamp = ptp_convert_timestamp(&hwtstamp,
READ_ONCE(sk->sk_bind_phc));
- if (ktime_to_timespec64_cond(hwtstamp, tss.ts + 2)) {
- empty = 0;
+ if (hwtstamp) {
+ tss.ts[2] = hwtstamp;
if ((tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) &&
!skb_is_err_queue(skb))
put_ts_pktinfo(msg, skb, if_index);
}
}
- if (!empty) {
+ if (tss.ts[0] | tss.ts[2]) {
if (sock_flag(sk, SOCK_TSTAMP_NEW))
put_cmsg_scm_timestamping64(msg, &tss);
else
--
2.53.0.473.g4a7958ca14-goog
next reply other threads:[~2026-03-04 1:27 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-04 1:27 Eric Dumazet [this message]
2026-03-04 3:26 ` [PATCH net-next] net: use ktime_t in struct scm_timestamping_internal Willem de Bruijn
2026-03-04 7:11 ` Jason Xing
2026-03-05 2:56 ` Eric Dumazet
2026-03-05 2:40 ` patchwork-bot+netdevbpf
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