On Fri, 2011-03-04 at 17:07 -0600, Tseng-Hui (Frank) Lin wrote:
> I don't have any measurable numbers. That's why I made it an option in
> case people wants to disable it. I do agree that the kernel has so many
> options that we should refrain from adding more. If the chance that the
> lazy switchi
On Sat, 2011-03-05 at 09:40 +1100, Benjamin Herrenschmidt wrote:
> > The lazy switching checks the shadow variable first before setting ACOP
> > register. This saves mtspr() only if the new value is the same as
> > current. If there are several coprocessors on the system, the ACOP
> > register may
On Fri, 2011-03-04 at 16:22 -0600, Tseng-Hui (Frank) Lin wrote:
> > Well, I don't know how you use icswx on P7+, but on Prism it's
> > definitely issued directly by userspace.
> >
> OK. You've got a point. I wasn't aware of Prism. HFI device driver is
> currently the only icswx user on P7. Could
On Sat, 2011-03-05 at 07:26 +1100, Benjamin Herrenschmidt wrote:
> On Fri, 2011-03-04 at 11:29 -0600, Tseng-Hui (Frank) Lin wrote:
> > On Fri, 2011-03-04 at 12:02 +1100, Benjamin Herrenschmidt wrote:
> > > On Wed, 2011-03-02 at 11:20 -0600, Tseng-Hui (Frank) Lin wrote:
> > >
> > > > +#define CPU_F
On Fri, 2011-03-04 at 11:29 -0600, Tseng-Hui (Frank) Lin wrote:
> On Fri, 2011-03-04 at 12:02 +1100, Benjamin Herrenschmidt wrote:
> > On Wed, 2011-03-02 at 11:20 -0600, Tseng-Hui (Frank) Lin wrote:
> >
> > > +#define CPU_FTR_ICSWX LONG_ASM_CONST(0x1000)
> >
> > Do we
On Fri, 2011-03-04 at 12:02 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2011-03-02 at 11:20 -0600, Tseng-Hui (Frank) Lin wrote:
>
> > +#define CPU_FTR_ICSWX LONG_ASM_CONST(0x1000)
>
> Do we want a userspace visible feature as well ? Or some other way to
> inform us
On Wed, 2011-03-02 at 11:20 -0600, Tseng-Hui (Frank) Lin wrote:
> +#define CPU_FTR_ICSWX LONG_ASM_CONST(0x1000)
Do we want a userspace visible feature as well ? Or some other way to
inform userspace that we support icswx ?
> index acac35d..b0c2549 100644
> --- a/arc
Icswx is a PowerPC co-processor instruction to send data to a
co-processor. On Book-S processors the LPAR_ID and process ID (PID) of
the owning process are registered in the window context of the
co-processor at initial time. When the icswx instruction is executed,
the L2 generates a cop-reg transa
