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
| ||
|
Date: Thu, 10 May 2007 12:43:53 -0700 From: Gagan Arneja <gaagaan@...il.com> To: Sridhar Samudrala <sri@...ibm.com> CC: Rick Jones <rick.jones2@...com>, Krishna Kumar2 <krkumar2@...ibm.com>, Evgeniy Polyakov <johnpol@....mipt.ru>, netdev@...r.kernel.org Subject: Re: [RFC] New driver API to speed up small packets xmits > small packets belonging to the same connection could be coalesced by > TCP, but this may help the case where multiple parallel connections are > sending small packets. It's not just small packets. The cost of calling hard_start_xmit/byte was rather high on your particular device. I've seen PCI read transaction in hard_start_xmit taking ~10,000 cycles on one particular device. Count the cycles your brand of NIC is taking in it's xmit_routine. The worse it is, the stronger your case for cluster transmits. Also, I think, you don't have to chain skbs, they're already chained in Qdisc->q. All you have to do is take the whole q and try to shove it at the device hoping for better results. But then, if you have rather big backlog, you run the risk of reordering packets if you have to requeue. > > Thanks > Sridhar -- Gagan > > - > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@...r.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists