Based on 1 normalized pattern(s):
licensed under gplv2
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 99 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170027.163048684@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Although we expect some small discrepancies for very large counts, we
seem to be able to count up to 64 billion instructions without too much
skew, so do so.
Also switch to using decimals for the instruction counts. This just
makes it easier to visually compare the expected vs actual values, as
well as the raw result from instructions.
Before:
instructions: result 68719476753 running/enabled 13101961654
cycles: result 38077343785 running/enabled 13101725752
Looped for 68719476736 instructions, overhead 17
Expected 68719476753
Actual 68719476753
Delta 0, 0.000000%
success: count_instructions
After:
instructions: result 64000000016 running/enabled 12197599964
cycles: result 35412471674 running/enabled 12197534110
Looped for 64000000000 instructions, overhead 16
Expected 64000000016
Actual 64000000016
Delta 0, 0.000000%
success: count_instructions
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Have a task eat some cpu while we are counting instructions to create
some scheduler pressure. The idea being to try and unearth any bugs we
have in counting that only appear when context switching is happening.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit adds a test of instruction counting using the PMU on powerpc.
Although the bulk of the code is architecture agnostic, the code needs to
run a precisely sized loop which is implemented in assembler.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
