X-Server 1.5.0 very sluggish

最近升到 xorg 1.5.0,某些操作 (terminal 快速更新) 會使 xserver 佔用非常多 cpu,看來是這個問題

Working on it … right now it looks like:

  • XShm pixmaps got accidentally reenabled in the course of Adam’s changes
  • Someone (maybe GTK, having tracked it down yet) is taking advantage of that by creating a shared pixmap and using it as the source for a composite operation.
  • That is not handled well in EXA and triggers migration of the destination back to system memory. (*)

– Owen

(*) One of the many cases where we’d be better off creating temporaries
in video memory to avoid migration.