[openib-general] RHEL 4 U3 - lost completions

[Or Gerlitz]

Bill Hartner wrote:
> 
> 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 - Is there a chance your code uses daemonize()?

Roland - If indeed, does it make sense that the problem does not 
reproduce with single threaded runs?

Or.