| 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: <1329317780.2437.50.camel@edumazet-HP-Compaq-6005-Pro-SFF-PC> Date: Wed, 15 Feb 2012 15:56:20 +0100 From: Eric Dumazet <eric.dumazet@...il.com> To: Neal Cardwell <ncardwell@...gle.com> Cc: alekcejk@...glemail.com, netdev@...r.kernel.org Subject: Re: Re: Re: Re: Re: Re: Re: Re: limited network bandwidth with 3.2.x kernels Le mercredi 15 février 2012 à 09:49 -0500, Neal Cardwell a écrit : > If there was an increase in the number of bytes charged to the socket > for each skb, without a corresponding increase in TCP receive buffer > size, that would explain a systematic decrease in receiver window that > would cause some paths, like perhaps these, to become > receiver-window-limited (which is consistent with the symptom of > stable bandwidth for a given path). > > Can you please try increasing the default TCP receiver window to see > if this helps; try this as root on the 3.2 machine: > > sysctl net.ipv4.tcp_rmem="4096 897664 897664" > > Basically making the middle number as big as the third number should > bump up the default receiver window size. > Neal, this was taken into account, check how sk_rcvbuf is dynamically handled in our stack. tcp_rmem[1] is the initial sk_rcvbuf, but its updated as soon as receive window changes If you check tcpdumps, you dont notice signs of receiver-window-limited. -- 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