Bug 1833186

Description of problem:

When 'Exceed on Demand' application is used to connect RHEL7 server and run gvim, gvim processes were monitored to be using CPU up to 100%.

I was able to reproduce that phenomenon which is described below. 



Version-Release number of selected component (if applicable):

libX11-1.6.7-2.el7.x86_64
libX11-common-1.6.7-2.el7.noarch
vim-X11-7.4.629-6.el7.x86_64                                                                                              
vim-common-7.4.629-6.el7.x86_64                             
vim-enhanced-7.4.629-6.el7.x86_64                          


How reproducible:

always under certain condition



Steps to Reproduce:

1. setup XDMCP server as described at https://access.redhat.com/solutions/2736

2. run gvim from a remote client 
 
 # ssh -X xdemcp_server -l yourid gvim 

3. check file descriptor information of the running gvim process and take a note on the fd of anon_inode:[eventfd]

 # ls -al /proc/`pidof gvim`/fd

 dr-x------. 2 hwanii hwanii  0  5ì  4 16:03 .
 dr-xr-xr-x. 9 hwanii hwanii  0  5ì  4 16:03 ..
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 0 -> /dev/pts/1
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 1 -> /dev/pts/1
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 2 -> /dev/pts/1
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 4 -> /home/hwanii/.test.swp
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 5 -> socket:[42592]
 lrwx------. 1 hwanii hwanii 64  5ì  4 16:03 6 -> anon_inode:[eventfd]        <==========


4. closed the anon_inode which was fd 6.

 # gdb  -batch -p $(pidof gvim) -ex "call close(6)" -ex cont -ex quit


Actual results:

  the gvim process starts using 100% CPU. 


Expected results:

  gvim process should not use high CPU utilization.


Additional info:

I am not sure if the condition will never be met when users only run software shipped by Red Hat as there was XDMCP of lightdm running in the customer environment.