Re: [PATCH 1/3] signal: avoid useless test in do_signal()

["Franck Bui-Huu" <vagabon.xyz@gmail.com>]

On 2/9/07, Ralf Baechle <ralf@linux-mips.org> wrote:
Ralf Baechle wrote:
> On Fri, Feb 09, 2007 at 04:07:36PM +0100, Franck Bui-Huu wrote:
>
> > -                       if (test_thread_flag(TIF_RESTORE_SIGMASK))
> > -                               clear_thread_flag(TIF_RESTORE_SIGMASK);
> This is a microoptimization.  The assumption here is TIF_RESTORE_SIGMASK
> will rarely need to be cleared and atomic operations are somewhat
> expensive if as in this case we have to assume the cacheline isn't
> held exclusive yet.
I missed that. You can forget this patch or maybe something like this
is more appropriate ?

        if (unlikely(test_thread_flag(TIF_RESTORE_SIGMASK)))
                clear_thread_flag(TIF_RESTORE_SIGMASK);
--
              Franck