netdev - RPS vs RFS

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

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 3 Apr 2014 13:14:04 -0600
From:	Sharat Masetty <sharat04@...il.com>
To:	netdev@...r.kernel.org
Cc:	sharat chandra <sharat04@...il.com>
Subject: RPS vs RFS

I am trying to understand the true benefit of RFS over RPS. In the
kernel documentation scaling.txt, the author talks about data cache
hitrate, can someone explain what this actually means? In which
scenarios would RFS be beneficial? Why would it help to have network
stack run on the same core on which the application for a stream/flow
is running?

Consider a NIC with a single receive queue, single interrupt line, and
iperf application is pulling data off this NIC card. In case where
iperf may still be running on the same core on which the interrupts
are delivered, then in that case the whole stack is pinned to the same
core, and would not be benefiting a lot from this scheme

References:
https://www.kernel.org/doc/Documentation/networking/scaling.txt

https://lwn.net/Articles/382428/

Regards,
Sharat
--
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