Date: Tue, 6 May 2003 00:10:24 -0700 (PDT) From: Julian Elischer <julian@elischer.org> To: David Xu <davidxu@freebsd.org> Cc: Daniel Eischen <eischen@pcnet1.pcnet.com> Subject: Re: kern_threads.c.. upcall question.. Message-ID: <Pine.BSF.4.21.0305052345410.4662-100000@InterJet.elischer.org> In-Reply-To: <04ec01c3139a$579093d0$f001a8c0@davidw2k>
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On Tue, 6 May 2003, David Xu wrote:
> I think the following patch is enough:
I agree that this seems enough from what I was reading.
(I like patches that have most lines starting with '-' :-)
>
> Index: kern_thread.c
> ===================================================================
> RCS file: /home/ncvs/src/sys/kern/kern_thread.c,v
> retrieving revision 1.129
> diff -u -r1.129 kern_thread.c
> --- kern_thread.c 1 May 2003 12:16:06 -0000 1.129
> +++ kern_thread.c 6 May 2003 06:32:10 -0000
> @@ -721,41 +721,6 @@
[...]
> void
> @@ -962,27 +927,25 @@
> uintptr_t mbx;
> void *addr;
> int error,temp;
> - ucontext_t uc;
> + mcontext_t mc;
>
> p = td->td_proc;
> kg = td->td_ksegrp;
>
> /* Export the user/machine context. */
> - addr = (void *)(&td->td_mailbox->tm_context);
> - error = copyin(addr, &uc, sizeof(ucontext_t));
> - if (error)
> - goto bad;
> -
> - thread_getcontext(td, &uc);
> - error = copyout(&uc, addr, sizeof(ucontext_t));
> - if (error)
> + get_mcontext(td, &mc, 0);
I think this could be optimised even more.
(why copy the FP regs if they are not valid) (etc).
but it is an improvement..
> + addr = (void *)(&td->td_mailbox->tm_context.uc_mcontext);
> + error = copyout(&mc, addr, sizeof(mcontext_t));
> + if (error)
> goto bad;
>
> /* Exports clock ticks in kernel mode */
> addr = (caddr_t)(&td->td_mailbox->tm_sticks);
> temp = fuword(addr) + td->td_usticks;
> - if (suword(addr, temp))
> + if (suword(addr, temp)) {
> + error = EFAULT;
> goto bad;
> + }
>
> /* Get address in latest mbox of list pointer */
> addr = (void *)(&td->td_mailbox->tm_next);
>
>
> And should we disable single threading testing or do
> double checking in thread_user_enter()? I think per-syscall
> PROC_LOCK is too expensive for us.
I am not sure which one you refer too.. Which single_threading
test?
BTW, I am a little unsure about the calling of thread_user_enter()
from thread_userret().
>
> David Xu
>
>
>
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