Describe events in a structured way via sysfs
in [Kernel]
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From: Johannes Berg on 22 Jun 2010 03:50 On Tue, 2010-06-22 at 09:33 +0200, Johannes Berg wrote: > > > > net/wlan0/events/ > > > > net/waln1/events/ > > > > .... > > > > net/walnN/events/ > > > > > > That's not appropriate either though since you may have multiple network > > > interfaces on the same hardware :) > > > > Doesn't net/wlan0...wlanN mean multiple network interfaces on the same > > hardware? > > Yes, but the trace points aren't per network interface but rather per > hardware piece. Which really just means that whoever writes the tracepoint needs to provide a struct device for where to put it (at least in the case of driver tracepoints), and then ideally some description of the device also gets put into the ringbuffer. Assuming you actually want to have the event show up in sysfs twice if it has multiple producers? I'd like that, it would make sense for a lot of cases since you might only care about one of the producers. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Lin Ming on 22 Jun 2010 04:00 On Tue, 2010-06-22 at 15:33 +0800, Johannes Berg wrote: > On Tue, 2010-06-22 at 15:22 +0800, Lin Ming wrote: > > > > > net/wlan0/events/ > > > > net/waln1/events/ > > > > .... > > > > net/walnN/events/ > > > > > > That's not appropriate either though since you may have multiple network > > > interfaces on the same hardware :) > > > > Doesn't net/wlan0...wlanN mean multiple network interfaces on the same > > hardware? > > Yes, but the trace points aren't per network interface but rather per > hardware piece. So it can only trace the whole hardware piece rather than a specific interface? If yes, then will change to - /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ioread32/ + /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/events/iwlwifi_dev_ioread32/ > > johannes > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Johannes Berg on 22 Jun 2010 04:00 On Tue, 2010-06-22 at 15:47 +0800, Lin Ming wrote: > So it can only trace the whole hardware piece rather than a specific > interface? > > If yes, then will change to > - /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/net/wlan0/events/iwlwifi_dev_ioread32/ > + /sys/devices/pci0000:00/0000:00:1c.1/0000:03:00.0/events/iwlwifi_dev_ioread32/ Yes, I guess you were right from the start and I was just thinking about it the wrong way. So presumably you'll somehow have to "instantiate" tracepoints for a given device? johannes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Lin Ming on 22 Jun 2010 04:10 On Tue, 2010-06-22 at 15:39 +0800, Johannes Berg wrote: > On Tue, 2010-06-22 at 09:33 +0200, Johannes Berg wrote: > > > > > > net/wlan0/events/ > > > > > net/waln1/events/ > > > > > .... > > > > > net/walnN/events/ > > > > > > > > That's not appropriate either though since you may have multiple network > > > > interfaces on the same hardware :) > > > > > > Doesn't net/wlan0...wlanN mean multiple network interfaces on the same > > > hardware? > > > > Yes, but the trace points aren't per network interface but rather per > > hardware piece. > > Which really just means that whoever writes the tracepoint needs to > provide a struct device for where to put it (at least in the case of > driver tracepoints), and then ideally some description of the device > also gets put into the ringbuffer. I'm not familiar with tracepoint code. Correct me if I'm wrong. Do you mean that, for example, if iwlwifi_dev_ioread32 event is traced, then the "device" info will get put into the ftrace ringbuffer? > > Assuming you actually want to have the event show up in sysfs twice if > it has multiple producers? I'd like that, it would make sense for a lot > of cases since you might only care about one of the producers. Yes, each producers has a "events" sysfs dir. > > johannes > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Johannes Berg on 22 Jun 2010 04:20
On Tue, 2010-06-22 at 16:04 +0800, Lin Ming wrote: > > Which really just means that whoever writes the tracepoint needs to > > provide a struct device for where to put it (at least in the case of > > driver tracepoints), and then ideally some description of the device > > also gets put into the ringbuffer. > > I'm not familiar with tracepoint code. Correct me if I'm wrong. > Do you mean that, for example, if iwlwifi_dev_ioread32 event is traced, > then the "device" info will get put into the ftrace ringbuffer? No, right now it doesn't. johannes -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |