Hi Eric, Thank you for the review! On 05/04/2024 15:29, Eric Dumazet wrote: > On Fri, Apr 5, 2024 at 3:06 PM Matthieu Baerts (NGI0) > <matttbe@xxxxxxxxxx> wrote: >> >> From: Geliang Tang <tanggeliang@xxxxxxxxxx> >> >> This patch adds "last time" fields last_data_sent, last_data_recv and >> last_ack_recv in struct mptcp_sock to record the last time data_sent, >> data_recv and ack_recv happened. They all are initialized as >> tcp_jiffies32 in __mptcp_init_sock(), and updated as tcp_jiffies32 too >> when data is sent in __subflow_push_pending(), data is received in >> __mptcp_move_skbs_from_subflow(), and ack is received in ack_update_msk(). >> >> Similar to tcpi_last_data_sent, tcpi_last_data_recv and tcpi_last_ack_recv >> exposed with TCP, this patch exposes the last time "an action happened" for >> MPTCP in mptcp_info, named mptcpi_last_data_sent, mptcpi_last_data_recv and >> mptcpi_last_ack_recv, calculated in mptcp_diag_fill_info() as the time >> deltas between now and the newly added last time fields in mptcp_sock. >> >> Also add three reserved bytes in struct mptcp_info not to have holes in >> this structure exposed to userspace. >> >> Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/446 >> Signed-off-by: Geliang Tang <tanggeliang@xxxxxxxxxx> >> Reviewed-by: Mat Martineau <martineau@xxxxxxxxxx> >> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@xxxxxxxxxx> >> --- >> include/uapi/linux/mptcp.h | 4 ++++ > > >> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c >> index 73fdf423de44..2ec2fdf9f4af 100644 >> --- a/net/mptcp/sockopt.c >> +++ b/net/mptcp/sockopt.c >> @@ -896,6 +896,7 @@ static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int >> void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) >> { >> struct sock *sk = (struct sock *)msk; >> + u32 now = tcp_jiffies32; >> u32 flags = 0; >> bool slow; >> >> @@ -930,6 +931,7 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) >> info->mptcpi_snd_una = msk->snd_una; >> info->mptcpi_rcv_nxt = msk->ack_seq; >> info->mptcpi_bytes_acked = msk->bytes_acked; >> + info->mptcpi_last_ack_recv = jiffies_to_msecs(now - msk->last_ack_recv); >> mptcp_data_unlock(sk); >> >> slow = lock_sock_fast(sk); > > lock_sock_fast(sk) can sleep and be quite slow... > > I suggest you reload now = jiffies32; Good point, it would make more sense to reload it after this lock! (or defining "now" only here, under this lock_sock_fast(), and move the block here above that is under the data spin lock, after, so all the "time" counter are "in sync"?) pw-bot: changes-requested > > >> @@ -942,6 +944,8 @@ void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) >> info->mptcpi_bytes_retrans = msk->bytes_retrans; >> info->mptcpi_subflows_total = info->mptcpi_subflows + >> __mptcp_has_initial_subflow(msk); >> + info->mptcpi_last_data_sent = jiffies_to_msecs(now - msk->last_data_sent); >> + info->mptcpi_last_data_recv = jiffies_to_msecs(now - msk->last_data_recv); >> unlock_sock_fast(sk, slow); >> } >> EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); >> >> -- >> 2.43.0 >> > Cheers, Matt -- Sponsored by the NGI0 Core fund.
