On Wed, Dec 04, 2013 at 08:46:27AM -0800, Christoph Hellwig wrote: > While doing my recent work on the generic smp function calls I noticed > that smp_call_function_single without the wait flag can't work, as > it allocates struct call_single_data on stack, and without the wait > flag will happily return before the IPI has been executed.
It doesn't actually; it uses a per-cpu one in the !wait case. The subsequent csd_lock() ensures it will wait for any prior user to complete, so only if you're doing multiple smp_call_function_single() invocations back-to-back will they queue up. > This affects the following callers: <snip> > kernel/stop_machine.c:stop_two_cpus() That site should work with .wait=1 just fine, but given the above, the .wait=0 doesn't appear problematic at all. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
