From: John Ronciak > Can we try a couple of things? 1) just comment out all the check for > link code in the e100 driver and give that a try and 2) just comment > out the update stats call and see if that works. These seem to be the > differences and we need to know which one is causing the problem.
First of all, I am still unable to get any traces of this in the latency tracer. Moreover, as I told before, removing parts of the watchdog usually made my eth0 nonfunctional (which is bad - this is an embedded system with ssh access). Hence, I explicitely instrumented the watchdog function with tsc. Output of the timings is done by a background thread, so the timings should not increase the runtime of the watchdog. Here are my results: If the watchdog doesn't get interrupted, preempted, or whatever, it spends 340 us in its body: * 303 us in the mii code * 36 us in the following code up to e100_adjust_adaptive_ifs * 1 us in the remaining code (I think my chip doesn't need any of those chip-specific fixups) The 303 us in the mii code are divided in the following way: * 101 us in mii_ethtool_gset * 135 us in the whole if * 67 us in mii_check_link This is with the udelay(2) instead of udelay(20) hack applied. With udelay(20), the mii times are 128 + 170 + 85 us, i.e. 383 us instead of 303 us, or >= 420 us for the whole watchdog. As the RTC runs with 8192 Hz during my tests, the watchdog is hit by 2-3 interrupts, which adds another 75 - 110 us to its total execution time, i.e. the time it blocks other rtprio 1 threads. -- Klaus Kusche (Software Development - Control Systems) KEBA AG Gewerbepark Urfahr, A-4041 Linz, Austria (Europe) Tel: +43 / 732 / 7090-3120 Fax: +43 / 732 / 7090-6301 E-Mail: [EMAIL PROTECTED] WWW: www.keba.com - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
