On Wed, 14 Feb 2007, Jeremy Fitzhardinge wrote: > Are there any special semantics that result from running the syslet > atoms in kernel mode? If I wanted to, could I write a syslet emulation > in userspace that's functionally identical to a kernel-based > implementation? (Obviously the performance characteristics will be > different.) > > I'm asking from the perspective of trying to work out the Valgrind > binding for this if it goes into the kernel. Valgrind needs to see all > the input and output values of each system call the client makes, > including those done within the syslet mechanism. It seems to me that > the easiest way to do this would be to intercept the syslet system > calls, and just implement them in usermode, performing the same series > of syscalls directly, and applying the Valgrind machinery to each one in > turn. > > Would this work?
Hopefully the API will simplify enough so that emulation will becomes easier. > Also, an unrelated question: is there enough control structure in place > to allow multiple syslet streams to synchronize with each other with > futexes? I think the whole point of an async execution of a syscall or a syslet, is that the syscall/syslet itself includes a non interlocked operations with other syscalls/syslets. So that the main scheduler thread can run in a lockless/singletask fashion. There are no technical obstacles that prevents you to do it, bu if you start adding locks (and hence having long-living syslet-threads) at that point you'll end up with a fully multithreaded solution. - 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/
