xmodmap really slow

[Olivier Fourdan]

On Fri, Nov 30, 2018 at 2:38 PM Alan Hourihane <alanh at fairlite.co.uk> wrote:
> [...]
> Many thanks for following and providing a patch.
>
> Might take me till Monday, but running....
>
> xmodmap -pke > /tmp/keydump
> xmodmap /tmp/keydump
>
> Where the last command invokes multi-second delays should be easy to test.

Unfortunately, I don't see any such slow down here, so I cannot
reproduce nor test if the change makes any difference.

Yet, several seconds is weird... I mean, even if optimizing that loop
in ilog2() would be nice, I can't imagine this being the source of
such long delays...

Can you reproduce with, say, Xephyr? If so maybe try running is strace :

  $ strace -Trttto strace.log Xephyr :12 &
  $ xmodmap -d :12 -pke > /tmp/keydump
  $ xmodmap -d :12 /tmp/keydump

That would tell if the Xserver (Xephyr in this case) is spending too
much time in a syscall, like for example reading a file or something?

Cheers,
Olivier