On 5/6/2024 11:51 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. >> >> Also skb_set_delivery_type_by_clockid is a new function which accepts >> clockid to determine the tstamp_type. >> >> 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> >> --- >> Changes since v5 >> - Avoided using garble function names as mentioned by >> Willem. >> - Implemented a conversion function stead of duplicating >> the same logic as mentioned by Willem. >> - Fixed indentation problems and minor documentation issues >> which mentions tstamp_type as a whole instead of bitfield >> notations. (Mentioned both by Willem and Martin) >> >> Changes since v4 >> - Introduce new function to directly delivery_time and >> another to set tstamp_type based on clockid. >> - Removed un-necessary comments in skbuff.h as >> enums were obvious and understood. >> >> Changes since v3 >> - Fixed inconsistent capitalization in skbuff.h >> - remove reference to MONO_DELIVERY_TIME_MASK in skbuff.h >> and point it to skb_tstamp_type now. >> - Explicitely setting SKB_CLOCK_MONO if valid transmit_time >> ip_send_unicast_reply >> - Keeping skb_tstamp inline with skb_clear_tstamp. >> - skb_set_delivery_time checks if timstamp is 0 and >> sets the tstamp_type to SKB_CLOCK_REAL. >> - Above comments are given by Willem >> - Found out that skbuff.h has access to uapi/linux/time.h >> So now instead of using CLOCK_REAL/CLOCK_MONO >> i am checking actual clockid_t directly to set tstamp_type >> example:- CLOCK_REALTIME/CLOCK_MONOTONIC >> - Compilation error fixed in >> net/ieee802154/6lowpan/reassembly.c >> >> Changes since v2 >> - Minor changes to commit subject >> >> Changes since v1 >> - Squashed the two commits into one as mentioned by Willem. >> - Introduced switch in skb_set_delivery_time. >> - Renamed and removed directionality aspects w.r.t tstamp_type >> as mentioned by Willem. >> >> include/linux/skbuff.h | 53 ++++++++++++++++------ >> include/net/inet_frag.h | 4 +- >> net/bridge/netfilter/nf_conntrack_bridge.c | 6 +-- >> net/core/dev.c | 2 +- >> net/core/filter.c | 10 ++-- >> net/ieee802154/6lowpan/reassembly.c | 2 +- >> net/ipv4/inet_fragment.c | 2 +- >> net/ipv4/ip_fragment.c | 2 +- >> net/ipv4/ip_output.c | 9 ++-- >> net/ipv4/tcp_output.c | 16 +++---- >> net/ipv6/ip6_output.c | 6 +-- >> net/ipv6/netfilter.c | 6 +-- >> net/ipv6/netfilter/nf_conntrack_reasm.c | 2 +- >> net/ipv6/reassembly.c | 2 +- >> net/ipv6/tcp_ipv6.c | 2 +- >> net/sched/act_bpf.c | 4 +- >> net/sched/cls_bpf.c | 4 +- >> 17 files changed, 80 insertions(+), 52 deletions(-) >> >> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h >> index 1c2902eaebd3..de3915e2bfdb 100644 >> --- a/include/linux/skbuff.h >> +++ b/include/linux/skbuff.h >> @@ -706,6 +706,11 @@ typedef unsigned int sk_buff_data_t; >> typedef unsigned char *sk_buff_data_t; >> #endif >> >> +enum skb_tstamp_type { >> + SKB_CLOCK_REALTIME, >> + SKB_CLOCK_MONOTONIC, >> +}; >> + >> /** >> * DOC: Basic sk_buff geometry >> * >> @@ -823,10 +828,9 @@ 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 >> - * delivery_time in mono clock base (i.e. EDT). Otherwise, the >> - * skb->tstamp has the (rcv) timestamp at ingress and >> - * delivery_time at egress. >> + * @tstamp_type: When set, skb->tstamp has the >> + * delivery_time in mono clock base Otherwise, the >> + * timestamp is considered real clock base. > > Missing period. More importantly, no longer conditional. It always > captures the type of skb->tstamp. > I think i should move the patchset 2 documentation to this patch itself. @tstamp_type: When set, skb->tstamp has the + * delivery_time clock base of skb->tstamp. >> --- a/net/ipv4/tcp_output.c >> +++ b/net/ipv4/tcp_output.c >> @@ -1301,7 +1301,7 @@ 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_type_by_clockid(skb, tp->tcp_wstamp_ns, CLOCK_MONOTONIC); >> if (clone_it) { >> oskb = skb; >> >> @@ -1655,7 +1655,7 @@ int tcp_fragment(struct sock *sk, enum tcp_queue tcp_queue, >> >> skb_split(skb, buff, len); >> >> - skb_set_delivery_time(buff, skb->tstamp, true); >> + skb_set_delivery_type_by_clockid(buff, skb->tstamp, CLOCK_MONOTONIC); >> tcp_fragment_tstamp(skb, buff); > > All these hardcoded monotonic calls in TCP can be the shorter version > > skb_set_delivery_type(.., SKB_CLOCK_MONOTONIC); I think i should directly call skb_set_delivery_time if i know that TCP always uses Monotonic clock base, rather than calling the wrapper api which does nothing but switch and then calls skb_set_delivery_Time. Makes sense. I will make the changes in v7 . >
