On Tue, 13 Feb 2007, Ingo Molnar wrote: > * Davide Libenzi <davidel@xmailserver.org> wrote: > > > > If this is going to be a generic AIO subsystem: > > > > > > - Cancellation of peding request > > > > What about the busy_async_threads list becoming a hash/rb_tree indexed > > by syslet_atom ptr. A cancel would lookup the thread and send a signal > > (of course, signal handling of the async threads should be set > > properly)? > > well, each async syslet has a separate TID at the moment, so if we want > a submitted syslet to be cancellable then we could return the TID of the > syslet handler (instead of the NULL) in sys_async_exec(). Then > user-space could send a signal the old-fashioned way, via sys_tkill(), > if it so wishes.
That works too. I was thinking about identifying syslets with the userspace ptr, but the TID is fine too. > the TID could also be used in a sys_async_wait_on() API. I.e. it would > be a natural, readily accessible 'cookie' for the pending work. TIDs can > be looked up lockless via RCU, so it's reasonably fast as well. > > ( Note that there's already a way to 'signal' pending syslets: do_exit() > in the user context will signal all async contexts (which results in > -EINTR of currently executing syscalls, wherever possible) and will > tear them down. But that's too crude for aio_cancel() i guess. ) Yup. - Davide - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
