Ben Greear <greearb@xxxxxxxxxxxxxxx> writes: > 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. That's not very reliable as "less than previous" assumption is not always true. > 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. Yeah, and we can always fix this later if there's a sudden need to get reliable numbers. -- Kalle Valo -- 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
