POSIX clock_gettime value is incorrect

* POSIX clock_gettime value is incorrect
@ 2021-02-05  6:23 Sam Daniel
  2021-02-05 14:35 ` Jan Kiszka
  0 siblings, 1 reply; 3+ messages in thread
From: Sam Daniel @ 2021-02-05  6:23 UTC (permalink / raw)
  To: xenomai

This is my test program, compiled/linked against the POSIX skin.
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int main(int argc, char* argv[]) {
    timespec time;
    clock_gettime(CLOCK_REALTIME, &time);
    fprintf(stdout, "%lu\n", time.tv_sec);
    return 0;
}

When I run it on my Xenomai system, this is its output:
$ ./clock
413

This appears to be roughly the number of seconds since boot:
$ uptime
04:40:44 up 7 min,  1 user,  load average: 0.36, 0.31, 0.16

Compiling without POSIX skin and running it has expected results:
$ ./clock
1612500006

Running date from my bash shell has expected results:
$ date
Fri Feb  5 04:38:10 UTC 2021

I ran the clocktest tool:
$ clocktest
== Testing built-in CLOCK_REALTIME (0)
CPU      ToD offset [us] ToD drift [us/s]      warps max delta [us]
--- -------------------- ---------------- ---------- --------------
  0  -1612499588990078.2           -0.046          0            0.0
  1  -1612499588990077.8            0.061          0            0.0
  2  -1612499588990077.8            0.004          0            0.0
  3  -1612499588990077.8            0.022          0            0.0

I do not understand its output, but to my eye it does not appear to be
"correct"...

After searching through the mailing list, I tried this:
$ clocktest -C CLOCK_HOST_REALTIME
clock_gettime failed for clock id 32
clock_gettime failed for clock id 32
XNVDSO_FEAT_HOST_REALTIME not available
clock_gettime failed for clock id 32
XNVDSO_FEAT_HOST_REALTIME not available

Which led me to this thread:
https://www.mail-archive.com/xenomai@xenomai.org/msg15904.html. I, too,
could not set CONFIG_XENO_OPT_HOSTRT or CONFIG_IPIPE_HAVE_HOSTRT


So I made this patch:

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 124398ef7336..28afa4b4b091 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -149,6 +149,7 @@ config ARM64
        select HAVE_KRETPROBES
        select HAVE_IPIPE_SUPPORT
        select HAVE_IPIPE_TRACER_SUPPORT
+       select IPIPE_HAVE_HOSTRT if IPIPE
        select IOMMU_DMA if IOMMU_SUPPORT
        select IRQ_DOMAIN
        select IRQ_FORCED_THREADING

CONFIG_XENO_OPT_HOSTRT and CONFIG_IPIPE_HAVE_HOSTRT were now both set
to y. Recompiled
and re-ran with this patch:
$  clocktest -C CLOCK_HOST_REALTIME
clock_gettime failed for clock id 32
clock_gettime failed for clock id 32
clock_gettime failed for clock id 32
hostrt data area is not live
hostrt data area is not live

I tried the extension flag as well:
$ clocktest -E -C CLOCK_HOST_REALTIME
clocktest: bad extension clock name 'CLOCK_HOST_REALTIME': Invalid argument

I am using Cobalt v3.1 with ipipe-core-4.19.55-arm64-4.patch. Is my kernel
building configured incorrectly? Am I missing some config parameter?

^ permalink raw reply related	[flat|nested] 3+ messages in thread