This patch series implements split core mode on POWER8. This enables up to 4
subcores per core which can each independently run guests (per guest SPRs like
SDR1, LPIDR etc are replicated per subcore). Lots more documentation on this
feature in the code and commit messages.
Most of this code is
From: Michael Ellerman m...@ellerman.id.au
As part of the support for split core on POWER8, we want to be able to
block splitting of the core while KVM VMs are active.
The logic to do that would be exactly the same as the code we currently
have for inhibiting onlining of secondaries.
Instead of
From: Michael Ellerman m...@ellerman.id.au
To support split core on POWER8 we need to modify various parts of the
KVM code to use threads_per_subcore instead of threads_per_core. On
systems that do not support split core threads_per_subcore ==
threads_per_core and these changes are a nop.
We use
From: Michael Ellerman m...@ellerman.id.au
On POWER8 we have a new concept of a subcore. This is what happens when
you take a regular core and split it. A subcore is a grouping of two or
four SMT threads, as well as a handfull of SPRs which allows the subcore
to appear as if it were a core from
From: Michael Ellerman m...@ellerman.id.au
To support split core we need to change the check in __cpu_up() that
determines if a cpu is allowed to come online.
Currently we refuse to online cpus which are not the primary thread
within their core.
On POWER8 with split core support this check
From: Michael Ellerman m...@ellerman.id.au
Upcoming POWER8 chips support a concept called split core. This is where
the core can be split into subcores that although not full cores, are
able to appear as full cores to a guest.
The splitting unsplitting procedure is mildly complicated, and
From: Michael Ellerman m...@ellerman.id.au
To support split core we need to be able to force all secondaries into
nap, so the core can detect they are idle and do an unsplit.
Currently power7_nap() will return without napping if there is an irq
pending. We want to ignore the pending irq and nap
Hi Mikey,
On Thu, Apr 24, 2014 at 11:02 AM, Michael Neuling mi...@neuling.org wrote:
+static DEVICE_ATTR(subcores_per_core, 0600,
+ show_subcores_per_core, store_subcores_per_core);
Can we make this 644, so users can query the state of the system
without being root? This is
Joel Stanley j...@jms.id.au wrote:
Hi Mikey,
On Thu, Apr 24, 2014 at 11:02 AM, Michael Neuling mi...@neuling.org wrote:
+static DEVICE_ATTR(subcores_per_core, 0600,
+ show_subcores_per_core, store_subcores_per_core);
Can we make this 644, so users can query the state of
