Change in behavior of poll() function timeout between RH 5.5 and RH 6.0

Hi,

We have a C program where we use the poll(fds, 1, timeout_msec) function to block for 10 ms, then send an event to another thread and then block again for 10 ms. We have been using this code for a while and it worked fine on all bare metal systems.

With Redhat 6.0, we are seeing a problem on a particular system. Sometimes, the timeout will be much greater than 10 ms for a period of time. We have seen a timeout as large as 500 ms.  During an 18 hour test, this large timeout might occur 2 or 3 times and last for 5 minutes each time. We have a Dell PowerEdge R410 system where the problem occurs. If we install Redhat 5.5 on this system, we do not see the problem, but if we install Redhat 6.0 on this system, the problem appears. We have another system, a Dell PowerEdge R310, where we do not see the problem with Redhat 6.0 installed.

Is there some way to figure out why we are seeing such large timeouts? Is this a known problem? Is there a workaround or patch to fix this? Thank you.