Abhishek Chauhan (ABC) wrote: > > > On 4/18/2024 11:47 AM, Willem de Bruijn wrote: > > Abhishek Chauhan wrote: > >> mono_delivery_time was added to check if skb->tstamp has delivery > >> time in mono clock base (i.e. EDT) otherwise skb->tstamp has > >> timestamp in ingress and delivery_time at egress. > >> > >> Renaming the bitfield from mono_delivery_time to tstamp_type is for > >> extensibilty for other timestamps such as userspace timestamp > >> (i.e. SO_TXTIME) set via sock opts. > >> > >> As we are renaming the mono_delivery_time to tstamp_type, it makes > >> sense to start assigning tstamp_type based on enum defined > >> in this commit. > >> > >> Earlier we used bool arg flag to check if the tstamp is mono in > >> function skb_set_delivery_time, Now the signature of the functions > >> accepts tstamp_type to distinguish between mono and real time. > >> > >> In future tstamp_type:1 can be extended to support userspace timestamp > >> by increasing the bitfield. > >> > >> Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@xxxxxxxxx/ > >> Signed-off-by: Abhishek Chauhan <quic_abchauha@xxxxxxxxxxx> > > > >> +/** > >> + * tstamp_type:1 can take 2 values each > >> + * represented by time base in skb > >> + * 0x0 => real timestamp_type > >> + * 0x1 => mono timestamp_type > >> + */ > >> +enum skb_tstamp_type { > >> + SKB_CLOCK_REAL, /* Time base is skb is REALTIME */ > >> + SKB_CLOCK_MONO, /* Time base is skb is MONOTONIC */ > >> +}; > >> + > > > > Can drop the comments. These names are self documenting. > > Noted! . I will take care of this > > > >> /** > >> * DOC: Basic sk_buff geometry > >> * > >> @@ -819,7 +830,7 @@ typedef unsigned char *sk_buff_data_t; > >> * @dst_pending_confirm: need to confirm neighbour > >> * @decrypted: Decrypted SKB > >> * @slow_gro: state present at GRO time, slower prepare step required > >> - * @mono_delivery_time: When set, skb->tstamp has the > >> + * @tstamp_type: When set, skb->tstamp has the > >> * delivery_time in mono clock base (i.e. EDT). Otherwise, the > >> * skb->tstamp has the (rcv) timestamp at ingress and > >> * delivery_time at egress. > > > > Is this still correct? I think all egress does now annotate correctly > > as SKB_CLOCK_MONO. So when not set it always is SKB_CLOCK_REAL. > > > That is correct. > > >> diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c > >> index 61119d42b0fd..a062f88c47c3 100644 > >> --- a/net/ipv4/tcp_output.c > >> +++ b/net/ipv4/tcp_output.c > >> @@ -1300,7 +1300,7 @@ static int __tcp_transmit_skb(struct sock *sk, struct sk_buff *skb, > >> tp = tcp_sk(sk); > >> prior_wstamp = tp->tcp_wstamp_ns; > >> tp->tcp_wstamp_ns = max(tp->tcp_wstamp_ns, tp->tcp_clock_cache); > >> - skb_set_delivery_time(skb, tp->tcp_wstamp_ns, true); > >> + skb_set_delivery_time(skb, tp->tcp_wstamp_ns, CLOCK_MONOTONIC); > > > > Multiple references to CLOCK_MONOTONIC left > > > I think i took care of all the references. Apologies if i didn't understand your comment here. On closer read, there is a type issue here. skb_set_delivery_time takes a u8 tstamp_type. But it is often passed a clockid_t, and that is also what the switch expects. But it does also get called with a tstamp_type in code like the following: + u8 tstamp_type = skb->tstamp_type; unsigned int hlen, ll_rs, mtu; ktime_t tstamp = skb->tstamp; struct ip_frag_state state; @@ -82,7 +82,7 @@ static int nf_br_ip_fragment(struct net *net, struct sock *sk, if (iter.frag) ip_fraglist_prepare(skb, &iter); - skb_set_delivery_time(skb, tstamp, mono_delivery_time); + skb_set_delivery_time(skb, tstamp, tstamp_type); So maybe we need two variants, one that takes a tstamp_type and one that tames a clockid_t? The first can be simple, not switch needed. Just apply the two stores.
