mbox

[0/5] alfred: TQ query optimizations

Message ID 4690435.IOLn72U8Ez@bentobox
Headers show

Message

Sven Eckelmann May 24, 2017, 10:31 a.m. UTC 
Hi,

alfred uses the TQ from batman-adv to find its best alfred neighbor. This best 
neighbor information is used by slave servers to request/publish data.

This is done for each server announcement packet by:

 * requesting the global translation table (netlink or debugfs) and then
   searching in it for the MAC address of the detected alfred server to find
   its originator address
 * requesting the originator table (netlink or debugfs) and then searching it
   it for the originator address of the detected alfred server to find its TQ
   value

This was previously done whenever a new announcement packet received by 
alfred. We've observed that this can be a problem on networks with a lot of 
master servers (~100) which can see each other, large translation tables and 
slow CPUs. alfred still worked but the CPU load by alfred was rather high
(~20% on an 560MHz AR9344).

The idea is now to avoid this lookup for master servers. And (for slave 
servers) to process all servers at once. This is done before the wants to push 
its local data to a master server in an sync interval.

The process which was described earlier was now changed to:

 * requesting the global translation table (netlink or debugfs) and then put
   MAC address and corresponding originator address in tg hash
 * requesting the originator table (netlink or debugfs) and then put
   originator address and corresponding TQ value orig hash
 * got through all servers:
   - search in tg hash for for the MAC address of the alfred server to find
   its originator address
   - search in orig hash for for the originator address of the alfred server
     to find its TQ value

These changes reduced the load on the previously mentioned devices 
significantly.

Kind regards,
	Sven


Sven Eckelmann (5):
  alfred: Move alfred specific netlink code in separate file
  alfred: Only query tq of remote master in slave mode
  alfred: Check the TQ of master servers before pushing data
  alfred: Cache the TQ values for each originator
  alfred: Cache the global translation table entries

 Makefile         |   1 +
 alfred.h         |   1 -
 batadv_query.c   | 227 +++++++++++++++++++++++++++++++++++++++++--------------
 batadv_query.h   |  25 +++++-
 batadv_querynl.c | 216 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 batadv_querynl.h |  34 +++++++++
 netlink.c        | 195 -----------------------------------------------
 netlink.h        |   7 --
 recv.c           |  15 +---
 server.c         |  56 +++++++++++++-
 10 files changed, 501 insertions(+), 276 deletions(-)
 create mode 100644 batadv_querynl.c
 create mode 100644 batadv_querynl.h