On Tue, 22 Apr 2008, Jens Axboe wrote: > > > > You forgot to free the "data" here? The waiter must also free the object, > > since now the callee does not. > > The ipi interrupt handler does that, see kfree() in > generic_smp_call_function_single_interrupt() or call_func_data_free() in > generic_smp_call_function_interrupt(). Hell no, it does *not*. Doing that for the waiting case would be a *huge* bug, since the waiter needs to wait until the flag is clear - and if the waitee free's the allocation, that will never happen. So the rule *must* be: - waiter frees - ipi interrupt frees non-waiting ones. because anything else cannot work. And you must have known that, because the code you pointed me to does *not* free the data at all. It just clears the FLAG_WAIT flag: + if (data->csd.flags & CSD_FLAG_WAIT) { + smp_wmb(); + data->csd.flags &= ~CSD_FLAG_WAIT; + } else + call_func_data_free(data); So please think about this some more. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html