On Wednesday, September 10, 2014 12:16:43 PM Yasuaki Ishimatsu wrote: > (2014/09/08 6:34), Rafael J. Wysocki wrote: > > On Friday, September 05, 2014 03:57:43 PM Yasuaki Ishimatsu wrote: > >> Container online uevent was deleted by "46394fd01 : ACPI / hotplug: > >> Move container-specific code out of the core" because container- > >> specific uevent is raised to udev by attaching container device. > >> But the container-specific uevent is not useful. > >> > >> In my box, conainer device has CPU and memory devices. In this case, > >> when hot adding container device, the following uevets are raised to > >> udev. > >> > >> # udevadm monitor --kernel > >> monitor will print the received events for: > >> KERNEL - the kernel uevent > >> > >> KERNEL[...] add /devices/system/container/ACPI0004:01 (container) > >> <snip> > >> KERNEL[...] add /devices/system/memory/memory2048 (memory) > >> KERNEL[...] add /devices/system/memory/memory2049 (memory) > >> <snip> > >> KERNEL[...] add /devices/system/memory/memory2063 (memory) > >> <snip> > >> KERNEL[...] add /devices/system/cpu/cpu60 (cpu) > >> <snip> > >> KERNEL[...] add /devices/system/cpu/cpu119 (cpu) > >> > >> When udev catches the container add uevent in my box, udev executes > >> user land script for onlining all child's devices. But memory and CPU > >> devices have not been attached at this time. So user land script fails. > >> > >> One of solutions is that user land script waits for all child's devices > >> to attach. But user land script has no way to know all child's devices > >> were attached. > >> > >> So the patch adds container online uevent to acpi_bus_sttach(). By > >> applying > >> the patch, container online uevent is raised to udev after all child's > >> devices were attached as follows: > >> > >> # udevadm monitor --kernel > >> monitor will print the received events for: > >> KERNEL - the kernel uevent > >> > >> KERNEL[...] add /devices/system/container/ACPI0004:01 (container) > >> <snip> > >> KERNEL[...] add /devices/system/memory/memory2048 (memory) > >> KERNEL[...] add /devices/system/memory/memory2049 (memory) > >> <snip> > >> KERNEL[...] add /devices/system/memory/memory2063 (memory) > >> <snip> > >> KERNEL[...] add /devices/system/cpu/cpu60 (cpu) > >> <snip> > >> KERNEL[...] add /devices/system/cpu/cpu119 (cpu) > >> KERNEL[...] online /devices/system/container/ACPI0004:01 (container) > >> > >> So if user land script is executed after raising the container online > >> uevent, it guarantees that all child's devices were attached. > > > > I see the problem, but I don't like the patch. > > > > For example, we don't need to match the container's name again, we can use > > the fact that we've already matched the container scan handler to it. > > > > Does the one below work too? > > Hi Rafael, > > Thank you for posting your patch. I confirmed that your patch fixed my issue > as folloes: > > # udevadm monitor --kernel > monitor will print the received events for: > KERNEL - the kernel uevent > > KERNEL[...] add /devices/system/container/ACPI0004:01 (container) > <snip> > KERNEL[...] add /devices/system/memory/memory2048 (memory) > <snip> > KERNEL[...] add /devices/system/memory/memory2063 (memory) > <snip> > KERNEL[...] add /devices/system/cpu/cpu60 (cpu) > <snip> > KERNEL[...] add /devices/system/cpu/cpu119 (cpu) > KERNEL[...] online /devices/system/container/ACPI0004:01 (container) > > So feel free to add "Tested-by : Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>" > to the patch. Thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
