lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <33f62bbd-51ed-475a-45f4-79226a235d6c@intel.com> Date: Thu, 16 Feb 2023 16:34:19 +0100 From: Alexander Lobakin <aleksander.lobakin@...el.com> To: Jesper Dangaard Brouer <jbrouer@...hat.com> CC: Paul Menzel <pmenzel@...gen.mpg.de>, <brouer@...hat.com>, <bpf@...r.kernel.org>, <xdp-hints@...-project.net>, <martin.lau@...nel.org>, <daniel@...earbox.net>, <netdev@...r.kernel.org>, <ast@...nel.org>, "Stanislav Fomichev" <sdf@...gle.com>, <yoong.siang.song@...el.com>, <anthony.l.nguyen@...el.com>, <intel-wired-lan@...ts.osuosl.org> Subject: Re: [xdp-hints] Re: [Intel-wired-lan] [PATCH bpf-next V1] igc: enable and fix RX hash usage by netstack From: Jesper Dangaard Brouer <jbrouer@...hat.com> Date: Thu, 16 Feb 2023 14:29:43 +0100 > > On 14/02/2023 16.00, Paul Menzel wrote: >> >> Thank you very much for your patch. > > Thanks for your review :-) [...] >>> static inline void igc_rx_hash(struct igc_ring *ring, >>> union igc_adv_rx_desc *rx_desc, >>> struct sk_buff *skb) >>> { >>> - if (ring->netdev->features & NETIF_F_RXHASH) >>> - skb_set_hash(skb, >>> - le32_to_cpu(rx_desc->wb.lower.hi_dword.rss), >>> - PKT_HASH_TYPE_L3); >>> + if (ring->netdev->features & NETIF_F_RXHASH) { >>> + u32 rss_hash = le32_to_cpu(rx_desc->wb.lower.hi_dword.rss); >>> + u8 rss_type = igc_rss_type(rx_desc); >> >> Amongst others, also here. > > Do notice I expect compiler to optimize this, such that is doesn't place > this variable on the stack. That's complicated I'd say. I mean, never trust the compilers. Yesterday I had a problem when the compiler (Clang 16) wasn't inlining oneliners (called only once) into one big function and was making 19-byte tiny functions from each of them, resulting in 10+ functions consisting of one call only => 2x jumps between functions :clownface: Especially when you use non-native words (u8/u16, also u64 for 32-bit arches) like this. > >>> + enum pkt_hash_types hash_type; >>> + >>> + hash_type = igc_rss_type_table[rss_type].hash_type; >>> + skb_set_hash(skb, rss_hash, hash_type); >>> + } >>> } >>> static void igc_rx_vlan(struct igc_ring *rx_ring, >>> @@ -6501,6 +6527,7 @@ static int igc_probe(struct pci_dev *pdev, >>> netdev->features |= NETIF_F_TSO; >>> netdev->features |= NETIF_F_TSO6; >>> netdev->features |= NETIF_F_TSO_ECN; >>> + netdev->features |= NETIF_F_RXHASH; >>> netdev->features |= NETIF_F_RXCSUM; >>> netdev->features |= NETIF_F_HW_CSUM; >>> netdev->features |= NETIF_F_SCTP_CRC; >> >> >> Kind regards, >> >> Paul >> >> >> [1]: https://notabs.org/coding/smallIntsBigPenalty.htm >> > Thanks, Olek
Powered by blists - more mailing lists