Re: [PATCH v2 08/11] powerpc/perf: add support for the hv gpci (get performance counter info) interface

On 02/24/2014 07:33 PM, Michael Ellerman wrote:

On Fri, 2014-14-02 at 22:02:12 UTC, Cody P Schafer wrote:

quoted

This provides a basic link between perf and hv_gpci. Notably, it does
not yet support transactions and does not list any events (they can
still be manually composed).

Can you explain how the HV_CAPS stuff ends up looking.

I'm not against adding it, but I'd like to understand how we expect it to be
used a bit better.

It's just a quick mechanism for me to expose some relevant information 
to userspace via sysfs using the hv_perf_caps_get() function's returned 
data. Documentation for this sysfs interface (and the rest) is in a 
later patch.
I don't expect any more uses to show up unless the firmware decides to 
add another capability bit (in which case I'll want to expose it as well).

quoted

diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
new file mode 100644
index 0000000..1f5d96d
--- /dev/null
+++ b/arch/powerpc/perf/hv-gpci.c
+
+static struct pmu h_gpci_pmu = {
+	.task_ctx_nr = perf_invalid_context,
+
+	.name = "hv_gpci",
+	.attr_groups = attr_groups,
+	.event_init  = h_gpci_event_init,
+	.add         = h_gpci_event_add,
+	.del         = h_gpci_event_del,

		     = h_gpci_event_stop,

quoted

+	.start       = h_gpci_event_start,
+	.stop        = h_gpci_event_stop,
+	.read        = h_gpci_event_read,

		     = h_gpci_event_update

quoted

+	.event_idx = perf_swevent_event_idx,
+};

whoops, thought I had fixed those 2 already.