Linux – Benefiting of sched_autogroup_enabled on the desktop

Do you have a kernel >= 2.6.38? If not, you may want to upgrade your kernel, so it includes "The ~200 Line Linux Kernel Patch That Does Wonders". This patch drastically increases the responsiveness of the Linux desktop. Since this patch was introduced, the only time my desktop was slow was when it was swapping, as Mikko Rantalainen pointed out, even with recent versions of X.

There is very insidious desktop file key - TryExec. According to docs:

TryExec

Path to an executable file on disk used to determine if the program is actually installed. If the path is not an absolute path, the file is looked up in the $PATH environment variable. If the file is not present or if it is not executable, the entry may be ignored (not be used in menus, for example).

So, it may result in missing menu entry if it is not filled properly. And by "properly" I mean that it always must point to actual executable.

Surprisingly, if you trying to launch your program in modified environment using env, it stops working. Here is example of invalid desktop file from my distro's package:

TryExec=env FONTCONFIG_FILE=/usr/share/fonts/fonts.conf telegram -noupdate
Exec=env FONTCONFIG_FILE=/usr/share/fonts/fonts.conf telegram -noupdate -- %u

It doesn't work because DE looks for env FONTCONFIG_FILE=/usr/share/fonts/fonts.conf telegram -noupdate executable, treating whole string (including spaces) as file path, which is missing, of course.

The solution is also simple: just specify path to actual executable (even relative):

TryExec=telegram