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4a263bf331
The INST_RETIRED.PREC_DIST event (0x0100) doesn't count on SPR.
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0
Performance counter stats for 'CPU(s) 0':
607,246 cpu/event=0xc0,umask=0x0/
0 cpu/event=0x0,umask=0x1/
The encoding for INST_RETIRED.PREC_DIST is pseudo-encoding, which
doesn't work on the generic counters. However, current perf extends its
mask to the generic counters.
The pseudo event-code for a fixed counter must be 0x00. Check and avoid
extending the mask for the fixed counter event which using the
pseudo-encoding, e.g., ref-cycles and PREC_DIST event.
With the patch,
perf stat -e cpu/event=0xc0,umask=0x0/,cpu/event=0x0,umask=0x1/ -C0
Performance counter stats for 'CPU(s) 0':
583,184 cpu/event=0xc0,umask=0x0/
583,048 cpu/event=0x0,umask=0x1/
Fixes: 2de71ee153 ("perf/x86/intel: Fix ICL/SPR INST_RETIRED.PREC_DIST encodings")
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1648482543-14923-1-git-send-email-kan.liang@linux.intel.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.