f7b58cbdb3
The 'perf mem' and 'perf c2c' tools are wrappers around 'perf record' with mem load/ store events. IBS tagged load/store sample provides most of the information needed for these tools. Wire in the "ibs_op//" event as mem-ldst event for AMD. There are some limitations though: Only load/store micro-ops provide mem/c2c information. Whereas, IBS does not have a way to choose a particular type of micro-op to tag. This results in many non-LS micro-ops being tagged which appear as N/A in the perf report. IBS, being an uncore pmu from kernel point of view[1], does not support per process monitoring. Thus, perf mem/c2c on AMD are currently supported in per-cpu mode only. Example: $ sudo perf mem record -- -c 10000 ^C[ perf record: Woken up 227 times to write data ] [ perf record: Captured and wrote 58.760 MB perf.data (836978 samples) ] $ sudo perf mem report -F mem,sample,snoop Samples: 836K of event 'ibs_op//', Event count (approx.): 8418762 Memory access Samples Snoop N/A 700620 N/A L1 hit 126675 N/A L2 hit 424 N/A L3 hit 664 HitM L3 hit 10 N/A Local RAM hit 2 N/A Remote RAM (1 hop) hit 8558 N/A Remote Cache (1 hop) hit 3 N/A Remote Cache (1 hop) hit 2 HitM Remote Cache (2 hops) hit 10 HitM Remote Cache (2 hops) hit 6 N/A Uncached hit 4 N/A $ [1]: https://lore.kernel.org/lkml/20220829113347.295-1-ravi.bangoria@amd.com Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ali Saidi <alisaidi@amazon.com> Cc: Ananth Narayan <ananth.narayan@amd.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joe Mario <jmario@redhat.com> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Kim Phillips <kim.phillips@amd.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sandipan Das <sandipan.das@amd.com> Cc: Santosh Shukla <santosh.shukla@amd.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Link: https://lore.kernel.org/r/20221006153946.7816-6-ravi.bangoria@amd.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.