[kvm-unit-tests PATCH v4 0/1] s390x: Add exit time test

Nico Boehr
2022-10-12T12:45:04Z

v3->v4:
---
* remove merge conflict markers (thanks Christian)

v2->v3:
---
* print average (thanks Claudio)
* have asm constraints look the same everywhere (thanks Claudio)
* rebase patchset on top of my migration sck patches[1] to make use of the
time.h improvements

v1->v2:
---
* add missing cc clobber, fix constraints for get_clock_us() (thanks
Thomas)
* avoid array and use pointer to const char* (thanks Thomas)
* add comment why testing nop makes sense (thanks Thomas)
* rework constraints and clobbers (thanks Thomas)

Sometimes, it is useful to measure the exit time of certain instructions
to e.g. identify performance regressions in instructions emulated by the
hypervisor.

This series adds a test which executes some instructions and measures
their execution time. Since their execution time depends a lot on the
environment at hand, all tests are reported as PASS currently.

The point of this series is not so much the instructions which have been
chosen here (but your ideas are welcome), but rather the general
question whether it makes sense to have a test like this in
kvm-unit-tests.

This series is based on my migration sck patches[1] to make use of the
time.h improvements there.

[1] https://lore.kernel.org/all/20221011170024.972135-1-nrb@linux.ibm.com/

Nico Boehr (1):
s390x: add exittime tests

s390x/Makefile | 1 +
s390x/exittime.c | 253 ++++++++++++++++++++++++++++++++++++++++++++
s390x/unittests.cfg | 4 +
3 files changed, 258 insertions(+)
create mode 100644 s390x/exittime.c

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2.36.1