Re: [PATCH] KVM: x86: Reduce retpoline performance impact in slot_handle_level_range()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, 2018-02-02 at 16:10 -0500, Paolo Bonzini wrote:
> > > On 2. Feb 2018, at 15:59, David Woodhouse <dwmw@xxxxxxxxxxxx> wrote:
> > > With retpoline, tight loops of "call this function for every XXX" are
> > > very much pessimised by taking a prediction miss *every* time.
> > > 
> > > This one showed up very high in our early testing, and it only has five
> > > things it'll ever call so make it take an 'op' enum instead of a
> > > function pointer and let's see how that works out...
> > > 
> > > Signed-off-by: David Woodhouse <dwmw@xxxxxxxxxxxx>
> 
> What about __always_inline instead?

Yeah, Linus suggested that and it looks like it generates sane (in fact
better) code. Will do some more testing and send it out for real
probably on Monday. Thanks.

Attachment: smime.p7s
Description: S/MIME cryptographic signature


[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]

  Powered by Linux