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I don't know how to enable SHMConfig on Ubuntu 12.04 so that I can run synclient -m 100 correctly.

I searched and solutions were with HAL daemon, but I don't have HAL, I think it was deprecated. Thanks

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Enter this command, it will give you access to change files on Nautilus

sudo nautilus

Enter Password → File System → USR → share → X11 → xorg.conf.d → 50-synaptics.conf

Now you should see this text and find the part that looks like this

Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"

This option is recommend on all Linux systems using evdev, but you want to add *Option "SHMConfig" "on" under MathIsTouchpad "on" so it looks like this:

Section "InputClass"
        Identifier "touchpad catchall"
        Driver "synaptics"
        MatchIsTouchpad "on"
        Option "SHMConfig" "on"

Save and exit and reboot.

Hope that helps.

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As mentioned in the synaptics(4) man page, the SHMConfig option can no longer be used to configure the driver:

Option "SHMConfig" "boolean"
      Switch  on/off shared memory for run-time debugging. This option
      does not have an effect on run-time configuration anymore and is
      only useful for hardware event debugging.

The preferred way to configure input devices now is through the XInput extension. The xinput command line tool provides one such way to do this. You can get a list of the input devices on the system with the following command:

xinput list

Using the numeric ID of the touchpad, you can list its properties with:

xinput list-props $device_id

You can then alter properties with a command like:

xinput set-prop $device_id $property_id value

I am not sure which property corresponds to synclient's -m option, but if it is still available to tweak you should see it here.

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synclient -m 100 is supposed to update every 100ms, and show useful [or in my case, cool] information about the touchpad, like display the borders of edge scrolling, and live updating of touches on the pad. – Matt Sep 13 '12 at 15:09
SHMConfig is no longer needed to configure the driver, but it is needed if you want to see real-time debugging info, eg using synclient-m 100. Adam's answer of setting it in an xorg config file worked for me. – hwjp May 11 '13 at 10:57

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