On Thu, 22 Feb 2007, Ingo Molnar wrote: > > * Ulrich Drepper <[EMAIL PROTECTED]> wrote: > > > Ingo Molnar wrote: > > > in terms of AIO, the best queueing model is i think what the kernel uses > > > internally: freely ordered, with barrier support. > > > > Speaking of AIO, how do you imagine lio_listio is implemented? If > > there is no asynchronous syscall it would mean creating a threadlet > > for each request but this means either waiting or creating > > several/many threads. > > my current thinking is that special-purpose (non-programmable, static) > APIs like aio_*() and lio_*(), where every last cycle of performance > matters, should be implemented using syslets - even if it is quite > tricky to write syslets (which they no doubt are - just compare the size > of syslet-test.c to threadlet-test.c). So i'd move syslets into the same > category as raw syscalls: pieces of the raw infrastructure between the > kernel and glibc, not an exposed API to apps. [and even if we keep them > in that category they still need quite a bit of API work, to clean up > the 32/64-bit issues, etc.]
Now that chains of syscalls can be way more easily handled with clets^wthreadlets, why would we need the whole syslets crud inside? Why can't aio_* be implemented with *simple* (or parallel/unrelated) syscall submit w/out the burden of a complex, limiting and heavy API (I won't list all the points against syslets, because I already did it enough times)? The compat layer only is so bad to not be even funny. Look at the code. Only removing the syslets crud would prolly cut 40% of it. And we did not even touch the compat code yet. - 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/
