[openib-general] RHEL 4 U3 - lost completions

[Bill Hartner]

Roland Dreier wrote:
> 
>     Bill> At 1st, I thought that was the case, a fork, however, I do
>     Bill> not think get_user_pages(), and the increment of the ref
>     Bill> count, will guarantee the page struct does not change for
>     Bill> RHEL 4 U3, I need to verify that though.
> 
> Are you doing a fork()?  If so then, yes, you will not be able to make
> your app work on a RHEL4 kernel.  After get_user_pages(), if you do a
> fork() then a copy-on-write will still happen, which will cause the
> physical page to move as you have discovered.

There is no fork that I am aware of in the code.  The pthread that
created the EVD and any other thread in the process that executes the
debug code sees the changed page struct.  I will try to recreate this in
a test app.

-Bill