e8d38345da
The evsel grouping fix iterates over evsels tracking the leader group
and the current position's group, updating the current position's leader
if an evsel is being forced into a group or groups changed. However,
groups changing isn't a sufficient condition as sorting may have
reordered events and the leader may no longer come first. For this
reason update all leaders whenever they disagree.
This change breaks certain Icelake+ metrics due to bugs in the
kernel. For example, tma_l3_bound with threshold enabled tries to
program the events:
{topdown-retiring,slots,CYCLE_ACTIVITY.STALLS_L2_MISS,topdown-fe-bound,EXE_ACTIVITY.BOUND_ON_STORES,EXE_ACTIVITY.1_PORTS_UTIL,topdown-be-bound,cpu/INT_MISC.RECOVERY_CYCLES,cmask=1,edge/,CYCLE_ACTIVITY.STALLS_L3_MISS,CPU_CLK_UNHALTED.THREAD,CYCLE_ACTIVITY.STALLS_MEM_ANY,EXE_ACTIVITY.2_PORTS_UTIL,CYCLE_ACTIVITY.STALLS_TOTAL,topdown-bad-spec}:W
fixing the perf metric event order gives:
{slots,topdown-retiring,topdown-fe-bound,topdown-be-bound,topdown-bad-spec,CYCLE_ACTIVITY.STALLS_L2_MISS,EXE_ACTIVITY.BOUND_ON_STORES,EXE_ACTIVITY.1_PORTS_UTIL,cpu/INT_MISC.RECOVERY_CYCLES,cmask=1,edge/,CYCLE_ACTIVITY.STALLS_L3_MISS,CPU_CLK_UNHALTED.THREAD,CYCLE_ACTIVITY.STALLS_MEM_ANY,EXE_ACTIVITY.2_PORTS_UTIL,CYCLE_ACTIVITY.STALLS_TOTAL}:W
Both of these return "<not counted>" for all events, whilst they work
with the group removed respecting that the perf metric events must still
be grouped. A vendor events update will need to add METRIC_NO_GROUP to
these metrics to workaround the kernel PMU driver issue.
Fixes: a90cc5a9eeab45ea ("perf evsel: Don't let evsel__group_pmu_name() traverse unsorted group")
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Andi Kleen <ak@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xing Zhengjun <zhengjun.xing@linux.intel.com>
Link: https://lore.kernel.org/r/20230719001836.198363-3-irogers@google.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.