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From: Larysa Zaremba <larysa.zaremba@intel.com>
To: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: bpf@vger.kernel.org, Stanislav Fomichev <sdf@google.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andrii@kernel.org>,
	Jakub Kicinski <kuba@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
	John Fastabend <john.fastabend@gmail.com>,
	KP Singh <kpsingh@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
	Jesse Brandeburg <jesse.brandeburg@intel.com>,
	Tony Nguyen <anthony.l.nguyen@intel.com>,
	Anatoly Burakov <anatoly.burakov@intel.com>,
	Jesper Dangaard Brouer <brouer@redhat.com>,
	Alexander Lobakin <alexandr.lobakin@intel.com>,
	Magnus Karlsson <magnus.karlsson@gmail.com>,
	Maryam Tahhan <mtahhan@redhat.com>,
	xdp-hints@xdp-project.net, netdev@vger.kernel.org,
	intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org
Subject: [xdp-hints] Re: [PATCH RESEND bpf-next 02/15] ice: make RX HW timestamp reading code more reusable
Date: Mon, 22 May 2023 17:07:33 +0200	[thread overview]
Message-ID: <ZGuFNesdPS5ijl/R@lincoln> (raw)
In-Reply-To: <ac1895cc-a7b0-e40c-7dfc-8ab301f39893@intel.com>

On Fri, May 19, 2023 at 06:52:13PM +0200, Alexander Lobakin wrote:
> From: Larysa Zaremba <larysa.zaremba@intel.com>
> Date: Fri, 12 May 2023 17:25:54 +0200
> 
> > Previously, we only needed RX HW timestamp in skb path,
> > hence all related code was written with skb in mind.
> > But with the addition of XDP hints via kfuncs to the ice driver,
> > the same logic will be needed in .xmo_() callbacks.
> 
> [...]
> 
> > @@ -2176,9 +2174,8 @@ ice_ptp_rx_hwtstamp(struct ice_rx_ring *rx_ring,
> >  	ts_high = le32_to_cpu(rx_desc->wb.flex_ts.ts_high);
> >  	ts_ns = ice_ptp_extend_32b_ts(cached_time, ts_high);
> >  
> > -	hwtstamps = skb_hwtstamps(skb);
> > -	memset(hwtstamps, 0, sizeof(*hwtstamps));
> > -	hwtstamps->hwtstamp = ns_to_ktime(ts_ns);
> > +	*dst = ts_ns;
> > +	return true;
> 
> Can't we use the same I wrote in the prev. comment, i.e. return 0 or
> timestamp? I don't think ts == 0 is valid.
>

Agreed with this in the answer to the previous email :)
 
> >  }
> >  
> >  /**
> 
> [...]
> 
> > + * The driver receives a notification in the receive descriptor with timestamp.
> > + * The timestamp is in ns, so we must convert the result first.
> > + */
> > +static void
> > +ice_ptp_rx_hwts_to_skb(struct ice_rx_ring *rx_ring,
> > +		       union ice_32b_rx_flex_desc *rx_desc,
> > +		       struct sk_buff *skb)
> > +{
> > +	struct skb_shared_hwtstamps *hwtstamps;
> > +	u64 ts_ns;
> > +
> > +	if (!ice_ptp_copy_rx_hwts_from_desc(rx_ring, rx_desc, &ts_ns))
> > +		return;
> > +
> > +	hwtstamps = skb_hwtstamps(skb);
> > +	memset(hwtstamps, 0, sizeof(*hwtstamps));
> > +	hwtstamps->hwtstamp = ns_to_ktime(ts_ns);
> 
> Ok, my optimizations aren't in this series :D
> If you look at the hwtimestamps in skb, you'll see all that can be
> minimized to just:
> 
> 	*skb_hwtstamps(skb) = (struct skb_shared_hwtstamps){
> 		.hwtstamp	= ns_to_ktime(ts_ns),
> 	};
> 
> Compiler will probably do its job, but I wouldn't always rely on it.
> Sometimes it's even able to not expand memset(8 bytes) to *(u64 *) = 0.

Ok, will fix.

> 
> > +}
> > +
> >  /**
> >   * ice_process_skb_fields - Populate skb header fields from Rx descriptor
> >   * @rx_ring: Rx descriptor ring packet is being transacted on
> > @@ -210,7 +235,7 @@ ice_process_skb_fields(struct ice_rx_ring *rx_ring,
> >  	ice_rx_csum(rx_ring, skb, rx_desc, ptype);
> >  
> >  	if (rx_ring->ptp_rx)
> > -		ice_ptp_rx_hwtstamp(rx_ring, rx_desc, skb);
> > +		ice_ptp_rx_hwts_to_skb(rx_ring, rx_desc, skb);
> >  }
> >  
> >  /**
> 
> Thanks,
> Olek

  reply	other threads:[~2023-05-22 15:10 UTC|newest]

Thread overview: 54+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-12 15:25 [xdp-hints] [PATCH RESEND bpf-next 00/15] new kfunc XDP hints and ice implementation Larysa Zaremba
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 01/15] ice: make RX hash reading code more reusable Larysa Zaremba
2023-05-19 16:46   ` [xdp-hints] " Alexander Lobakin
2023-05-22 15:03     ` Larysa Zaremba
2023-05-22 15:36       ` Alexander Lobakin
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 02/15] ice: make RX HW timestamp " Larysa Zaremba
2023-05-19 16:52   ` [xdp-hints] " Alexander Lobakin
2023-05-22 15:07     ` Larysa Zaremba [this message]
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 03/15] ice: make RX checksum checking " Larysa Zaremba
2023-05-22 15:51   ` [xdp-hints] " Alexander Lobakin
2023-05-22 16:05     ` Larysa Zaremba
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 04/15] ice: Make ptype internal to descriptor info processing Larysa Zaremba
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 05/15] ice: Introduce ice_xdp_buff Larysa Zaremba
2023-05-22 16:46   ` [xdp-hints] " Alexander Lobakin
2023-05-23  8:02     ` Larysa Zaremba
2023-05-25 11:02       ` Alexander Lobakin
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 06/15] ice: Support HW timestamp hint Larysa Zaremba
2023-05-12 18:19   ` [xdp-hints] " Stanislav Fomichev
2023-05-16 16:17     ` Jesper Dangaard Brouer
2023-05-12 15:25 ` [xdp-hints] [PATCH RESEND bpf-next 07/15] ice: Support RX hash XDP hint Larysa Zaremba
2023-05-12 18:22   ` [xdp-hints] " Stanislav Fomichev
2023-05-15 13:46     ` Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 08/15] ice: Support XDP hints in AF_XDP ZC mode Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 09/15] xdp: Add VLAN tag hint Larysa Zaremba
2023-05-12 18:28   ` [xdp-hints] " Stanislav Fomichev
2023-05-15 15:36   ` Jesper Dangaard Brouer
2023-05-15 16:09     ` Larysa Zaremba
2023-05-22  8:37       ` Jesper Dangaard Brouer
2023-05-22 15:48         ` Larysa Zaremba
2023-05-23 10:16           ` Jesper Dangaard Brouer
2023-05-23 17:35             ` Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 10/15] ice: Implement " Larysa Zaremba
2023-05-12 18:31   ` [xdp-hints] " Stanislav Fomichev
2023-05-15 13:41     ` Larysa Zaremba
2023-05-15 15:07       ` Jesper Dangaard Brouer
2023-05-15 15:45         ` Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 11/15] xdp: Add checksum level hint Larysa Zaremba
2023-05-12 18:34   ` [xdp-hints] " Stanislav Fomichev
2023-05-15 13:49     ` Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 12/15] ice: Implement " Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 13/15] selftests/bpf: Allow VLAN packets in xdp_hw_metadata Larysa Zaremba
2023-05-12 18:33   ` [xdp-hints] " Stanislav Fomichev
2023-05-15 14:05     ` Larysa Zaremba
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 14/15] net, xdp: allow metadata > 32 Larysa Zaremba
2023-05-15 16:17   ` [xdp-hints] " Jesper Dangaard Brouer
2023-05-15 17:08     ` Larysa Zaremba
2023-05-16 12:37       ` Alexander Lobakin
2023-05-16 15:35         ` Jesper Dangaard Brouer
2023-05-19 16:35           ` Alexander Lobakin
2023-05-22 11:41             ` Jesper Dangaard Brouer
2023-05-22 15:28               ` Alexander Lobakin
2023-05-22 15:55                 ` Daniel Borkmann
2023-05-12 15:26 ` [xdp-hints] [PATCH RESEND bpf-next 15/15] selftests/bpf: Add flags and new hints to xdp_hw_metadata Larysa Zaremba
2023-05-12 18:37   ` [xdp-hints] " Stanislav Fomichev

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