From: William C. <wc...@re...> - 2014-02-10 16:15:58
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On 02/10/2014 10:18 AM, Maynard Johnson wrote: > On 02/10/2014 08:32 AM, William Cohen wrote: >> On 02/10/2014 05:20 AM, Will Deacon wrote: >>> On Fri, Feb 07, 2014 at 11:00:45PM +0000, Maynard Johnson wrote: >>>> On 02/04/2014 02:10 PM, William Cohen wrote: >>>>> This revised patch addresses Will Deacon's comment about possible >>>>> follow on implementations of the pmu unit such as pmuv4 for armv8 >>>>> processors. The name is armv8-pmuv3 to match up with what the kernel >>>>> reports for perf events. If an aarch64 processors has implementation >>>>> specific events, it can be named appropriately and it can include the >>>>> events in this patch. >>>>> >>>>> The "make distcheck" works fine with this version of the patch. >>>>> >>>>> William Cohen (1): >>>>> Provide basic AArch64 support >>>>> >>>>> events/Makefile.am | 1 + >>>>> events/arm/armv8-pmuv3/events | 38 ++++++++++++++++++++++++++++++++++++++ >>>>> events/arm/armv8-pmuv3/unit_masks | 4 ++++ >>>> Will and Will, >>> >>> Hi Maynard, >>> >>>> Maybe I'm confused. The initial patch had events/arm/armv8-common/. Will D's comment was: >>>> The uses of armv8_common and CPU_ARM_V8_COMMON would be more precise >>>> if we mentioned pmuv3 in there somewhere. At some point we'll probably >>>> get PMUv4, and then the common events might not be common anymore. >>>> >>>> The events/arm/armv8-pmuv3 events and unit masks files have the comment >>>> "ARMv8 architected events" in them. Shouldn't we have a >>>> events/arm/armv8-pmuv3-common directory with the actual events defined, >>>> and then the processor-specific files (in events/arm/armv8-pmuv3) would >>>> just "include" the armv8-pmuv3-common? >>> >>> I don't think this patch adds any processor-specific events, so if/when they >>> appear I was anticipating them including events/arm/armv8-pmuv3/events. >>> >>> So you'd have something like events/arm/armv8-ca57/events which would >>> include:arm/armv8-pmuv3. > I know I'm beating a dead horse, but nothing either of you have said has made it clear to me why this scenario is different from the various armv7 processor models including armv7-common/events. If there's no clear distinction, then why veer from the existing pattern of directory naming, where said directory will include events and unit mask files that are intended (expected?) to be included by processor specific events/unit mask files? Granted, the pattern is not set in concrete -- ARM uses "common" in the directory name; Intel uses "arch_perfmon"; current IBM Power uses "architected_events_v1" -- but the names make the intent pretty clear. > > -Maynard Hi Maynard, I don't have a significant preference for the name. I would just like to come to a consensus on the name and get the patch merged in. There are the following possible choices: armv8: armv8-common: (name scheme following earlier armvN processors in OProfile) armv8-pmuv3: (name scheme used by the upstream kernel) armv8-common-pmuv3: The last patch used armv8-pmuv3 to match the name used in the kernel, "arm/armv8-pmuv3" . However, the kernel is not particularly consistent in its naming of arm processors PMUs. The 32-bit arm processors PMUs have names "ARMv7 Cortex-A<N>", "v6", and "v6mpcore". All of the current arm processor have specific events sets and none display the armv7-common as the name of the events. The krait just includes the armv7-common. Of those choices above what would a user perfer to see? Is something with "armv8-common-pmuv3" or something with "common" in the name that the user wants to see? -Will |