On Sun, Dec 13, 2009 at 11:54:02AM -0800, Richard Henderson wrote: > On 12/13/2009 11:28 AM, Aurelien Jarno wrote: > >Is it really necessary to flush all the TB here? QEMU should already > >discard TB that have been modified. > > No. But I meant to look into this more carefully with a view to > disabling the other checking within QEMU and speed things up a tad. > It seems to me that the explicit checking with each memory write > ought to only be necessary on architectures like x86 that don't > architecturally require a flush insn to be used.
This is actually done only on the first write access to a page and not to each write, so it should not be so costly. It is however something to investigate, as I agree that removing the checks can add some speed-up. > I can drop this fragment if necessary for patch acceptance, however. > I think it is better to drop it until we have a better view of the whole thing. You can add a comment saying that an optimisation might be possible here. -- Aurelien Jarno GPG: 1024D/F1BCDB73 aurel...@aurel32.net http://www.aurel32.net
