Messages in this thread | | | Date | Mon, 3 Mar 2014 07:28:28 +0000 | Subject | Re: [PATCH RFC/RFT v3 1/9] drivers: base: add new class "cpu" to group cpu devices | From | Sudeep Holla <> |
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Hi Greg,
On Sat, Mar 1, 2014 at 12:42 AM, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > On Wed, Feb 19, 2014 at 04:06:08PM +0000, Sudeep Holla wrote: >> From: Sudeep Holla <sudeep.holla@arm.com> >> >> This patch creates a new class called "cpu" and assigns it to all the >> cpu devices. This helps in grouping all the cpu devices and associated >> child devices under the same class. >> >> This patch also: >> 1. modifies the get_parent_device to return the legacy path >> (/sys/devices/system/cpu/..) for the cpu class devices to support >> existing sysfs ABI >> 2. avoids creating link in the class directory pointing to the device as >> there would be per-cpu instance of these devices with the same name >> 3. makes sure subsystem symlink continues pointing to cpu bus instead of >> cpu class for cpu devices >> >> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> >> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Does the sysfs layout change at all with this patch applied? >
No change to the existing layout, it just adds new entries, e.g. device symlink.
Before this patch: / # ls /sys/devices/system/cpu/cpu0/ -l total 0 drwxr-xr-x 5 root 0 0 Jan 1 00:02 cpuidle -rw-r--r-- 1 root 0 4096 Jan 1 00:02 online drwxr-xr-x 2 root 0 0 Jan 1 00:02 power lrwxrwxrwx 1 root 0 0 Jan 1 00:02 subsystem -> ../../../../bus/cpu drwxr-xr-x 2 root 0 0 Jan 1 00:02 topology -rw-r--r-- 1 root 0 4096 Jan 1 00:02 uevent
After this patch: /sys/class/cpu # ls /sys/devices/system/cpu/cpu0 -l total 0 drwxr-xr-x 6 root 0 0 Jan 1 00:00 cache drwxr-xr-x 5 root 0 0 Jan 1 00:00 cpuidle lrwxrwxrwx 1 root 0 0 Jan 1 00:00 device -> ../../cpu -rw-r--r-- 1 root 0 4096 Jan 1 00:00 online drwxr-xr-x 2 root 0 0 Jan 1 00:00 power lrwxrwxrwx 1 root 0 0 Jan 1 00:00 subsystem -> ../../../../bus/cpu drwxr-xr-x 2 root 0 0 Jan 1 00:00 topology -rw-r--r-- 1 root 0 4096 Jan 1 00:00 uevent
Regards, Sudeep
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