Hi Michael,
thank you for your reply.
On 28/05/2019 07:19, Michael Ellerman wrote:
Vincenzo Frascino [off-list ref] writes:
quoted
The current version of the multiarch vDSO selftest verifies only
gettimeofday.
Extend the vDSO selftest to clock_getres, to verify that the
syscall and the vDSO library function return the same information.
The extension has been used to verify the hrtimer_resoltion fix.
This is passing for me even without patch 1 applied, shouldn't it fail
without the fix? What am I missing?
This is correct, because during the refactoring process I missed an "n" :)
if·((x.tv_sec·!=·y.tv_sec)·||·(x.tv_sec·!=·y.tv_sec))
Should be:
if·((x.tv_sec·!=·y.tv_sec)·||·(x.tv_nsec·!=·y.tv_nsec))
My mistake, I am going to fix the test and re-post v5 of this set.
Without my patch if you pass "highres=off" to the kernel (as a command line
parameter) it leads to a broken implementation of clock_getres since the value
of CLOCK_REALTIME_RES does not change at runtime.
Expected result (with highres=off):
# uname -r
5.2.0-rc2
# ./vdso_clock_getres
clock_id: CLOCK_REALTIME [FAIL]
clock_id: CLOCK_BOOTTIME [PASS]
clock_id: CLOCK_TAI [PASS]
clock_id: CLOCK_REALTIME_COARSE [PASS]
clock_id: CLOCK_MONOTONIC [FAIL]
clock_id: CLOCK_MONOTONIC_RAW [PASS]
clock_id: CLOCK_MONOTONIC_COARSE [PASS]
The reason of this behavior is that the only clocks supported by getres on
powerpc are CLOCK_REALTIME and CLOCK_MONOTONIC, the rest on the clocks use
always syscalls.
# uname -r
5.2.0-rc2-gcc-8.2.0
# ./vdso_clock_getres
clock_id: CLOCK_REALTIME [PASS]
clock_id: CLOCK_BOOTTIME [PASS]
clock_id: CLOCK_TAI [PASS]
clock_id: CLOCK_REALTIME_COARSE [PASS]
clock_id: CLOCK_MONOTONIC [PASS]
clock_id: CLOCK_MONOTONIC_RAW [PASS]
clock_id: CLOCK_MONOTONIC_COARSE [PASS]
cheers
quoted
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
Note: This patch is independent from the others in this series, hence it
can be merged singularly by the kselftest maintainers.
tools/testing/selftests/vDSO/Makefile | 2 +
.../selftests/vDSO/vdso_clock_getres.c | 124 ++++++++++++++++++
2 files changed, 126 insertions(+)
create mode 100644 tools/testing/selftests/vDSO/vdso_clock_getres.c
--
Regards,
Vincenzo