[RFC 13/13] wpa_supplicant: Support minimum interval between scan attempts.

[Ben Greear]

On 10/22/2011 11:47 AM, Jouni Malinen wrote:
> On Fri, Oct 14, 2011 at 03:34:37PM -0700, greearb at candelatech.com wrote:
>> When running lots of vifs, they can all end up wanting to
>> scan right after the other.  This leaves too little time for
>> useful work to happen.  Allow users to configure a minimum
>> timer interval (in seconds) between scans.  Default is zero,
>> which is current behaviour.
>
> Doing this in wpa_supplicant_req_scan() in this way is likely to cause
> problems for various cases that depend on a quick scan, like P2P. I
> understand that this is for special testing purposes, but this
> configuration item would have unexpected behavior in some cases.
>
> Do you know which wpa_supplicant_req_scan() call(s) are the most likely
> once to hit the issues with large number of interfaces? It could be
> nicer to modify one of those callers rather than enforcing this type of
> strict minimum for all scan requests.

I don't know, it's been a while since I wrote this code.
Maybe it could be a per-interface variable instead of in
the core code?  That way, it could be set for normal stations if desired,
but let p2p do things as fast as it wants?  I'd have to look at how difficult
that would be to code up, though.

>
>> +	wpa_s->last_scan_rx_sec = time(NULL);
>
> Need to use os_get_time() instead of time().

Agreed.

Thanks,
Ben

>


-- 
Ben Greear <greearb at candelatech.com>
Candela Technologies Inc  http://www.candelatech.com