On 08/08/2014 08:55 AM, Dave Taht wrote: > On Fri, Aug 8, 2014 at 8:42 AM, Ben Greear <greearb@xxxxxxxxxxxxxxx> wrote: >> On 08/08/2014 02:06 AM, Kalle Valo wrote: >>> Ben Greear <greearb@xxxxxxxxxxxxxxx> writes: >>> >>>> I'm working on a patch to report the stats seen in debugfs/...ath10k/fw_stats >>>> as ethtool stats, somewhat similar to how ath9k does it. >>>> >>>> I notice that my user-space tool is reporting huge numbers because >>>> the stats are reset to zero when firmware restarts, and so my tool >>>> thinks the stats wrapped. >>>> >>>> I can fix my tool easily enough, but I first wanted to see if >>>> anyone had strong feelings about keeping the stats from resetting >>>> to zero by storing history and calculating diffs in the driver. >>>> >>>> I think my preference is to punt this to user-space, but if >>>> someone feels otherwise, please let me know sooner than later. >>> >>> I also prefer to have this in user space, but how does user space know >>> when the stats have been zeroed? >> >> Poll often enough that it cannot increment more than 2 billion (or other large number) >> between polls, and then if polled value is less than previous (and difference is > 2 billion), >> we know we had a reset and not a wrap. > > I do kind of prefer 64 bit counters in the general case. Nuke it from > orbit, it's the only way to be sure. It's 64-bit to user-space, but that means nothing because firmware uses 32-bit (or even 16 bit in some cases, probably) internally. A great deal of counters are the same, so be very careful when trying to keep long term counters grabbed from firmware/drivers/hardware. And, stations come and go when you re-associate, so all sorts of wifi counters reset themselves all the time... Thanks, Ben > >> User-space stats will not be perfect in the case of firmware resets, or resets >> after the 'large number', but nothing is going to make it perfect, and in >> practice, this seems good enough. >> >> Thanks, >> Ben >> >> -- >> Ben Greear <greearb@xxxxxxxxxxxxxxx> >> Candela Technologies Inc http://www.candelatech.com >> >> >> _______________________________________________ >> ath10k mailing list >> ath10k@xxxxxxxxxxxxxxxxxxx >> http://lists.infradead.org/mailman/listinfo/ath10k > > > -- Ben Greear <greearb@xxxxxxxxxxxxxxx> Candela Technologies Inc http://www.candelatech.com -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
