On Fri, Aug 29, 2008 at 12:29:42PM -0400, Gregory Haskins wrote:
Yes it will be only contended when gettimeofday() races with the timer
interrupt. You could try to run gettimeofday() in a loop and see how
long it holds up.
But anyways from the theory you should crash when it happens.
Writes to kernel data are not allowed in vsyscalls and your read_lock clearly
does a write.