---------------------------
-What: sys_sysctl
-When: September 2010
-Option: CONFIG_SYSCTL_SYSCALL
-Why: The same information is available in a more convenient from
- /proc/sys, and none of the sysctl variables appear to be
- important performance wise.
-
- Binary sysctls are a long standing source of subtle kernel
- bugs and security issues.
-
- When I looked several months ago all I could find after
- searching several distributions were 5 user space programs and
- glibc (which falls back to /proc/sys) using this syscall.
-
- The man page for sysctl(2) documents it as unusable for user
- space programs.
-
- sysctl(2) is not generally ABI compatible to a 32bit user
- space application on a 64bit and a 32bit kernel.
-
- For the last several months the policy has been no new binary
- sysctls and no one has put forward an argument to use them.
-
- Binary sysctls issues seem to keep happening appearing so
- properly deprecating them (with a warning to user space) and a
- 2 year grace warning period will mean eventually we can kill
- them and end the pain.
-
- In the mean time individual binary sysctls can be dealt with
- in a piecewise fashion.
-
-Who: Eric Biederman <ebiederm@xmission.com>
-
----------------------------
-
What: /proc/<pid>/oom_adj
When: August 2012
Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
information log when acer-wmi initial.
Who: Lee, Chun-Yi <jlee@novell.com>
+---------------------------
+
+What: /sys/devices/platform/_UDC_/udc/_UDC_/is_dualspeed file and
+ is_dualspeed line in /sys/devices/platform/ci13xxx_*/udc/device file.
+When: 3.8
+Why: The is_dualspeed file is superseded by maximum_speed in the same
+ directory and is_dualspeed line in device file is superseded by
+ max_speed line in the same file.
+
+ The maximum_speed/max_speed specifies maximum speed supported by UDC.
+ To check if dualspeeed is supported, check if the value is >= 3.
+ Various possible speeds are defined in <linux/usb/ch9.h>.
+Who: Michal Nazarewicz <mina86@mina86.com>
+
----------------------------
What: The XFS nodelaylog mount option