Messages in this thread |  | | Date | Tue, 25 Feb 2014 14:19:14 -0800 | From | Cody P Schafer <> | Subject | Re: [PATCH v2 01/11] perf: add PMU_RANGE_ATTR() helper for use by sw-like pmus |
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On 02/25/2014 12:33 PM, Cody P Schafer wrote: > On 02/24/2014 07:33 PM, Michael Ellerman wrote: >> On Fri, 2014-14-02 at 22:02:05 UTC, Cody P Schafer wrote: >>> Add PMU_RANGE_ATTR() and PMU_RANGE_RESV() (for reserved areas) which >>> generate functions to extract the relevent bits from >>> event->attr.config{,1,2} for use by sw-like pmus where the >>> 'config{,1,2}' values don't map directly to hardware registers. >>> >>> Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com> >>> --- >>> include/linux/perf_event.h | 17 +++++++++++++++++ >>> 1 file changed, 17 insertions(+) >>> >>> diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h >>> index e56b07f..2702e91 100644 >>> --- a/include/linux/perf_event.h >>> +++ b/include/linux/perf_event.h >>> @@ -871,4 +871,21 @@ _name##_show(struct device >>> *dev, \ >>> \ >>> static struct device_attribute format_attr_##_name = __ATTR_RO(_name) >>> >>> +#define PMU_RANGE_ATTR(name, attr_var, bit_start, bit_end) \ >>> +PMU_FORMAT_ATTR(name, #attr_var ":" #bit_start "-" #bit_end); \ >>> +PMU_RANGE_RESV(name, attr_var, bit_start, bit_end) >>> + >>> +#define PMU_RANGE_RESV(name, attr_var, bit_start, bit_end) \ >>> +static u64 event_get_##name##_max(void) \ >>> +{ \ >>> + int bits = (bit_end) - (bit_start) + 1; \ >>> + return ((0x1ULL << (bits - 1ULL)) - 1ULL) | \ >>> + (0xFULL << (bits - 4ULL)); \ >>> +} \ >>> +static u64 event_get_##name(struct perf_event *event) \ >>> +{ \ >>> + return (event->attr.attr_var >> (bit_start)) & \ >>> + event_get_##name##_max(); \ >>> +} >> >> I still don't like the names. >> >> EVENT_GETTER_AND_FORMAT() > > EVENT_RANGE() > > I'd prefer to describe the intended usage rather than what is generated > both in case we change some of the specifics later, and to provide > additional information to the developers beyond what a simple code > reading gives. > >> EVENT_RESERVED() > > Sure. The PMU_* naming was just based on the PMU_FORMAT_ATTR() naming, > so I kept it for continuity with the existing API. Maybe > EVENT_RANGE_RESERVED() would be more appropriate? >
Thinking about this a bit more, EVENT_RANGE() and EVENT_RANGE_RESERVED() aren't quite ideal either. The "EVENT" name collides with the files we put in the event/ dir, which these macros generate files for the format/ dir. Maybe:
FORMAT_RANGE() and FORMAT_RANGE_RESERVED() or PMU_FORMAT_RANGE(), PMU_FORMAT_RANGE_RESERVED()
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