Looking over Linux kernel list archives and other places, it looks like when the "RCU Implementation" choice hit the mainline non-patched kernel, the option to choose "Preemptable RCU" caused quite a stir as many latent bugs were uncovered. It looks like many bugs got fixed, but is it safe now? Should one enable CONFIG_PREEMPT_RCU on a 2.6.29.6 kernel these days? It seems to be available even without RT patches. -- + Brent A. Busby + "We've all heard that a million monkeys + UNIX Systems Admin + banging on a million typewriters will + University of Chicago + eventually reproduce the entire works of + Physical Sciences Div. + Shakespeare. Now, thanks to the Internet, + James Franck Institute + we know this is not true." -Robert Wilensky