3337bf41e0
An extra count on ebb_state.stats.pmc_count[PMC_INDEX(pmc)] is being per- formed when count_pmc() is used to reset PMCs on a few selftests. This extra pmc_count can occasionally invalidate results, such as the ones from cycles_test shown hereafter. The ebb_check_count() failed with an above the upper limit error due to the extra value on ebb_state.stats.pmc_count. Furthermore, this extra count is also indicated by extra PMC1 trace_log on the output of the cycle test (as well as on pmc56_overflow_test): ========== ... [21]: counter = 8 [22]: register SPRN_MMCR0 = 0x0000000080000080 [23]: register SPRN_PMC1 = 0x0000000080000004 [24]: counter = 9 [25]: register SPRN_MMCR0 = 0x0000000080000080 [26]: register SPRN_PMC1 = 0x0000000080000004 [27]: counter = 10 [28]: register SPRN_MMCR0 = 0x0000000080000080 [29]: register SPRN_PMC1 = 0x0000000080000004 >> [30]: register SPRN_PMC1 = 0x000000004000051e PMC1 count (0x280000546) above upper limit 0x2800003e8 (+0x15e) [FAIL] Test FAILED on line 52 failure: cycles ========== Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com> Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200626164737.21943-1-desnesn@linux.ibm.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.