Messages in this thread | | | Date | Mon, 27 Feb 2023 10:26:28 +0000 | Subject | Re: v4: Re: [PATCH v7 00/15] coresight: Add new API to allocate trace source ID values | From | Suzuki K Poulose <> |
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Mike,
Please could you send all the perf tool related patches as a seperate series, with all the tags to Arnaldo directly at -rc1.
Please add a cover letter explaining that the kernel changes are available upstream.
Kind regards Suzuki
On 20/02/2023 16:24, Suzuki K Poulose wrote: > Arnaldo > > Gentle ping > > > On 31/01/2023 11:49, Suzuki K Poulose wrote: >> Hi Arnaldo >> >> On 24/01/2023 11:36, Suzuki K Poulose wrote: >>> Hi Arnaldo >>> >>> Gentle ping. >>> >>> On 19/01/2023 12:00, Suzuki K Poulose wrote: >>>> Hi Arnaldo, >>>> >>>> On 16/01/2023 12:49, Mike Leach wrote: >>>>> The current method for allocating trace source ID values to sources is >>>>> to use a fixed algorithm for CPU based sources of (cpu_num * 2 + >>>>> 0x10). >>>>> The STM is allocated ID 0x1. >>>>> >>>>> This fixed algorithm is used in both the CoreSight driver code, and by >>>>> perf when writing the trace metadata in the AUXTRACE_INFO record. >>>>> >>>>> The method needs replacing as currently:- >>>>> 1. It is inefficient in using available IDs. >>>>> 2. Does not scale to larger systems with many cores and the algorithm >>>>> has no limits so will generate invalid trace IDs for cpu number > 44. >>>>> >>>>> Additionally requirements to allocate additional system IDs on some >>>>> systems have been seen. >>>>> >>>>> This patch set introduces an API that allows the allocation of >>>>> trace IDs >>>>> in a dynamic manner. >>>>> >>>>> Architecturally reserved IDs are never allocated, and the system is >>>>> limited to allocating only valid IDs. >>>>> >>>>> Each of the current trace sources ETM3.x, ETM4.x and STM is updated >>>>> to use >>>>> the new API. >>>>> >>>>> For the ETMx.x devices IDs are allocated on certain events >>>>> a) When using sysfs, an ID will be allocated on hardware enable, or >>>>> a read of >>>>> sysfs TRCTRACEID register and freed when the sysfs reset is written. >>>>> >>>>> b) When using perf, ID is allocated on during setup AUX event, and >>>>> freed on >>>>> event free. IDs are communicated using the AUX_OUTPUT_HW_ID packet. >>>>> The ID allocator is notified when perf sessions start and stop >>>>> so CPU based IDs are kept constant throughout any perf session. >>>>> >>>>> >>>>> Note: This patchset breaks some backward compatibility for perf >>>>> record and >>>>> perf report. >>>>> >>>>> The version of the AUXTRACE_INFO has been updated to reflect the >>>>> fact that >>>>> the trace source IDs are generated differently. This will >>>>> mean older versions of perf report cannot decode the newer file. >>>>> >>>>> Appies to coresight/next >>>>> >>> >>> ... >>> >>>>> Mike Leach (15): >>>>> coresight: trace-id: Add API to dynamically assign Trace ID values >>>>> coresight: Remove obsolete Trace ID unniqueness checks >>>>> coresight: perf: traceid: Add perf ID allocation and notifiers >>>>> coresight: stm: Update STM driver to use Trace ID API >>>>> coresight: etm4x: Update ETM4 driver to use Trace ID API >>>>> coresight: etm3x: Update ETM3 driver to use Trace ID API >>>>> coresight: etmX.X: stm: Remove trace_id() callback >>>>> coresight: trace id: Remove legacy get trace ID function. >>>>> perf: cs-etm: Move mapping of Trace ID and cpu into helper function >>>>> perf: cs-etm: Update record event to use new Trace ID protocol >>>>> kernel: events: Export perf_report_aux_output_id() >>>>> perf: cs-etm: Handle PERF_RECORD_AUX_OUTPUT_HW_ID packet >>>>> coresight: events: PERF_RECORD_AUX_OUTPUT_HW_ID used for Trace ID >>>>> coresight: trace-id: Add debug & test macros to Trace ID allocation >>>>> coresight: etm3x: docs: Alter sysfs documentation for trace id >>>>> updates >>>> >>>> I have pushed the kernel patches on this series to coresight tree >>>> next[0]. >>>> >>>> I will be sending them out to Greg for v6.3. Please could you queue the >>>> perf tool changes in the series ? i.e., Patches 9,10 and 12. >>>> >>>> >>>> [0] >>>> https://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git/log/?h=next >>>> >>> >>> Please could you pick up the perf tool changes above ? >> >> Please could you confirm if you are able to queue the perf tool >> changes ? Or would you like me route it via coresight tree ? >> >> Kind regards >> Suzuki >> > > > Suzuki >
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