Messages in this thread | | | Subject | Re: [RESEND PATCH V2 5/6] perf/x86/intel/uncore: Generic support for the PCI sub driver | From | "Liang, Kan" <> | Date | Tue, 22 Sep 2020 09:05:06 -0400 |
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On 9/21/2020 6:19 PM, Bjorn Helgaas wrote: > On Mon, Sep 14, 2020 at 07:34:19AM -0700, kan.liang@linux.intel.com wrote: >> From: Kan Liang <kan.liang@linux.intel.com> >> >> Some uncore counters may be located in the configuration space of a PCI >> device, which already has a bonded driver. Currently, the uncore driver >> cannot register a PCI uncore PMU for these counters, because, to >> register a PCI uncore PMU, the uncore driver must be bond to the device. >> However, one device can only have one bonded driver. >> >> Add an uncore PCI sub driver to support such kind of devices. >> >> The sub driver doesn't own the device. In initialization, the sub >> driver searches the device via pci_get_device(), and register the >> corresponding PMU for the device. In the meantime, the sub driver >> registeris a PCI bus notifier, which is used to notify the sub driver >> once the device is removed. The sub driver can unregister the PMU >> accordingly. > > s/registeris/registers/ > > It looks like this only handles hot-remove of the device, not hot-add. > Maybe that's OK for your use case, I dunno, so just pointing it out. >
Hi Bjorn,
Thanks for the review.
Yes, the patch only supports the hot-remove for now, because - I didn't get any requests for the hot-add support. I doubt anyone hot-adds a Root Port device in practice. - To be honest, I don't have a test case to verify the hot-add of a Root Port device. I used the command line below to test the hot-remove. sudo bash -c 'echo 1 > /sys/bus/pci/devices/0000\:14\:04.0/remove' Then the device is gone. I have no idea how to add it back.
So I only implemented the hot-remove in this patch. If anyone requires the hot-add, I can add it later separately.
Thanks, Kan
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