tst: Provide test for getrusage
Commit Message
This commit adds test to check if getrusage provides correct time
accounting for some busy wait loop.
To be more specific - the time is measured in a loop by wrappers
from glibc's libsupport and checked if timeout has passed.
Afterwards, the data from struct rusage, namely ru_stime and ru_utime
is summed up and compared with time from busy waiting.
---
sysdeps/unix/sysv/linux/Makefile | 2 +-
sysdeps/unix/sysv/linux/tst-getrusage.c | 55 +++++++++++++++++++++++++
2 files changed, 56 insertions(+), 1 deletion(-)
create mode 100644 sysdeps/unix/sysv/linux/tst-getrusage.c
Comments
On Mär 15 2021, Lukasz Majewski wrote:
> diff --git a/sysdeps/unix/sysv/linux/tst-getrusage.c b/sysdeps/unix/sysv/linux/tst-getrusage.c
> new file mode 100644
> index 0000000000..068becdadb
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-getrusage.c
> @@ -0,0 +1,55 @@
> +/* Test for getrusage
> + Copyright (C) 2021 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <time.h>
> +#include <sys/resource.h>
> +#include <support/check.h>
> +#include <support/timespec.h>
> +
> +#define TST_GETRUSAGE_TIMEOUT 1
> +
> +static int
> +do_test (void)
> +{
> + struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
> + struct rusage ru;
> + int ret;
> +
> + tv_then = xclock_now (CLOCK_REALTIME);
> + /* Busy wait for 1 second. */
> + do
> + {
> + tv_now = xclock_now (CLOCK_REALTIME);
> + r = timespec_sub (tv_now, tv_then);
> + } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );
What happens if the process stalls for a second?
Andreas.
Hi Andreas,
> On Mär 15 2021, Lukasz Majewski wrote:
>
> > diff --git a/sysdeps/unix/sysv/linux/tst-getrusage.c
> > b/sysdeps/unix/sysv/linux/tst-getrusage.c new file mode 100644
> > index 0000000000..068becdadb
> > --- /dev/null
> > +++ b/sysdeps/unix/sysv/linux/tst-getrusage.c
> > @@ -0,0 +1,55 @@
> > +/* Test for getrusage
> > + Copyright (C) 2021 Free Software Foundation, Inc.
> > + This file is part of the GNU C Library.
> > +
> > + The GNU C Library is free software; you can redistribute it
> > and/or
> > + modify it under the terms of the GNU Lesser General Public
> > + License as published by the Free Software Foundation; either
> > + version 2.1 of the License, or (at your option) any later
> > version. +
> > + The GNU C Library is distributed in the hope that it will be
> > useful,
> > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > GNU
> > + Lesser General Public License for more details.
> > +
> > + You should have received a copy of the GNU Lesser General Public
> > + License along with the GNU C Library; if not, see
> > + <https://www.gnu.org/licenses/>. */
> > +
> > +#include <time.h>
> > +#include <sys/resource.h>
> > +#include <support/check.h>
> > +#include <support/timespec.h>
> > +
> > +#define TST_GETRUSAGE_TIMEOUT 1
> > +
> > +static int
> > +do_test (void)
> > +{
> > + struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
> > + struct rusage ru;
> > + int ret;
> > +
> > + tv_then = xclock_now (CLOCK_REALTIME);
> > + /* Busy wait for 1 second. */
> > + do
> > + {
> > + tv_now = xclock_now (CLOCK_REALTIME);
> > + r = timespec_sub (tv_now, tv_then);
> > + } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );
>
> What happens if the process stalls for a second?
I think that the glibc's test infrastructure will kill it - the default
timeout is 2 seconds.
As a result the test will fail.
>
> Andreas.
>
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
Hi Andreas,
> Hi Andreas,
>
> > On Mär 15 2021, Lukasz Majewski wrote:
> >
> > > diff --git a/sysdeps/unix/sysv/linux/tst-getrusage.c
> > > b/sysdeps/unix/sysv/linux/tst-getrusage.c new file mode 100644
> > > index 0000000000..068becdadb
> > > --- /dev/null
> > > +++ b/sysdeps/unix/sysv/linux/tst-getrusage.c
> > > @@ -0,0 +1,55 @@
> > > +/* Test for getrusage
> > > + Copyright (C) 2021 Free Software Foundation, Inc.
> > > + This file is part of the GNU C Library.
> > > +
> > > + The GNU C Library is free software; you can redistribute it
> > > and/or
> > > + modify it under the terms of the GNU Lesser General Public
> > > + License as published by the Free Software Foundation; either
> > > + version 2.1 of the License, or (at your option) any later
> > > version. +
> > > + The GNU C Library is distributed in the hope that it will be
> > > useful,
> > > + but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> > > GNU
> > > + Lesser General Public License for more details.
> > > +
> > > + You should have received a copy of the GNU Lesser General
> > > Public
> > > + License along with the GNU C Library; if not, see
> > > + <https://www.gnu.org/licenses/>. */
> > > +
> > > +#include <time.h>
> > > +#include <sys/resource.h>
> > > +#include <support/check.h>
> > > +#include <support/timespec.h>
> > > +
> > > +#define TST_GETRUSAGE_TIMEOUT 1
> > > +
> > > +static int
> > > +do_test (void)
> > > +{
> > > + struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
> > > + struct rusage ru;
> > > + int ret;
> > > +
> > > + tv_then = xclock_now (CLOCK_REALTIME);
> > > + /* Busy wait for 1 second. */
> > > + do
> > > + {
> > > + tv_now = xclock_now (CLOCK_REALTIME);
> > > + r = timespec_sub (tv_now, tv_then);
> > > + } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );
> >
> > What happens if the process stalls for a second?
>
> I think that the glibc's test infrastructure will kill it - the
> default timeout is 2 seconds.
>
> As a result the test will fail.
On the other hand - the proposed approach with busy waiting was the
natural one to check if accounting from getrusage is correct.
Maybe you (or anybody else from the community) have a better idea on how
to force the process to be "running" (active) for some time?
Maybe I could modify the C test code to perform following bash
operation:
cat /dev/urandom | gzip -9 > /dev/null
and replace /dev/urandom with some large (generated in place) file?
However, this would pose additional dependencies (gzip) on glibc test
suite.
>
> >
> > Andreas.
> >
>
>
>
>
> Best regards,
>
> Lukasz Majewski
>
> --
>
> DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email:
> lukma@denx.de
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
On Mär 17 2021, Lukasz Majewski wrote:
> Maybe you (or anybody else from the community) have a better idea on how
> to force the process to be "running" (active) for some time?
You don't get real-time scheduling on Unix. You always have to account
for a process stalling for an arbitrary amount of time.
Andreas.
Hi Andreas,
> On Mär 17 2021, Lukasz Majewski wrote:
>
> > Maybe you (or anybody else from the community) have a better idea
> > on how to force the process to be "running" (active) for some time?
> >
>
> You don't get real-time scheduling on Unix. You always have to
> account for a process stalling for an arbitrary amount of time.
>
> Andreas.
>
I'm just looking for ideas on how to reliably test getrusage.
Do you have any ideas?
Best regards,
Lukasz Majewski
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de
On 15/03/2021 07:42, Lukasz Majewski wrote:
> This commit adds test to check if getrusage provides correct time
> accounting for some busy wait loop.
>
> To be more specific - the time is measured in a loop by wrappers
> from glibc's libsupport and checked if timeout has passed.
>
> Afterwards, the data from struct rusage, namely ru_stime and ru_utime
> is summed up and compared with time from busy waiting.
> ---
> sysdeps/unix/sysv/linux/Makefile | 2 +-
> sysdeps/unix/sysv/linux/tst-getrusage.c | 55 +++++++++++++++++++++++++
> 2 files changed, 56 insertions(+), 1 deletion(-)
> create mode 100644 sysdeps/unix/sysv/linux/tst-getrusage.c
>
> diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
> index 6a45ac820a..a93fa4ca50 100644
> --- a/sysdeps/unix/sysv/linux/Makefile
> +++ b/sysdeps/unix/sysv/linux/Makefile
> @@ -113,7 +113,7 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
> tst-tgkill tst-sysvsem-linux tst-sysvmsg-linux tst-sysvshm-linux \
> tst-timerfd tst-ppoll tst-futimens tst-utime tst-utimes \
> tst-clock_adjtime tst-adjtimex tst-ntp_adjtime tst-futimes \
> - tst-lutimes tst-ntp_gettime tst-ntp_gettimex
> + tst-lutimes tst-ntp_gettime tst-ntp_gettimex tst-getrusage
> tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc
> tests-time64 += \
> tst-futimes-time64\
> diff --git a/sysdeps/unix/sysv/linux/tst-getrusage.c b/sysdeps/unix/sysv/linux/tst-getrusage.c
> new file mode 100644
> index 0000000000..068becdadb
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/tst-getrusage.c
> @@ -0,0 +1,55 @@
> +/* Test for getrusage
> + Copyright (C) 2021 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <time.h>
> +#include <sys/resource.h>
> +#include <support/check.h>
> +#include <support/timespec.h>
> +
> +#define TST_GETRUSAGE_TIMEOUT 1
> +
> +static int
> +do_test (void)
> +{
> + struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
> + struct rusage ru;
> + int ret;
> +
> + tv_then = xclock_now (CLOCK_REALTIME);
> + /* Busy wait for 1 second. */
> + do
> + {
> + tv_now = xclock_now (CLOCK_REALTIME);
> + r = timespec_sub (tv_now, tv_then);
> + } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );
> +
> + ret = getrusage (RUSAGE_SELF, &ru);
> + if (ret == -1)
> + FAIL_EXIT1 ("getrusage failed: %m\n");
> +
> + gru_u = make_timespec (ru.ru_utime.tv_sec, ru.ru_utime.tv_usec * 1000);
> + gru_s = make_timespec (ru.ru_stime.tv_sec, ru.ru_stime.tv_usec * 1000);
> + s = timespec_add (gru_u, gru_s);
> +
> + TEST_COMPARE (support_timespec_check_in_range
> + ((struct timespec) { 1, 0 }, s, 0.8, 1.2), 1);
> +
> + return 0;
> +}
> +
> +#include <support/test-driver.c>
>
Timer accounting tests are tricky to get right and prone to show a
lot of false positive failures and has bitten us in the past (check
04deeaa9ea74 and 9a29f1a2ae3d4b).
So I think we should be as simple as possible and take in consideration
that tests will run a timer shared machine so even with a busy wait the
result timer might not take in consideration the desirable timeout.
So for geturage (which afaik is also deprecated on future POSIX) I
more simpler tests would be to:
1. Check for invalid 'who' (the EFAULT result from man-pages only
trigger where syscall is issued directly, which is not always
the case for glibc).
2. Issue getusage and check if the ru_utime.tv_nsec and
ru_stime.tv_nsec are within the microseconds range.
3. Do some very short busy wait (10ms) and check if the
ru_utime.tv_sec and ru_stime.tv_sec are equal or larger
than the previous one.
Also, I think this tests should generic, so move to resource
folder.
@@ -113,7 +113,7 @@ tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
tst-tgkill tst-sysvsem-linux tst-sysvmsg-linux tst-sysvshm-linux \
tst-timerfd tst-ppoll tst-futimens tst-utime tst-utimes \
tst-clock_adjtime tst-adjtimex tst-ntp_adjtime tst-futimes \
- tst-lutimes tst-ntp_gettime tst-ntp_gettimex
+ tst-lutimes tst-ntp_gettime tst-ntp_gettimex tst-getrusage
tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc
tests-time64 += \
tst-futimes-time64\
new file mode 100644
@@ -0,0 +1,55 @@
+/* Test for getrusage
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#include <time.h>
+#include <sys/resource.h>
+#include <support/check.h>
+#include <support/timespec.h>
+
+#define TST_GETRUSAGE_TIMEOUT 1
+
+static int
+do_test (void)
+{
+ struct timespec tv_then, tv_now, gru_u, gru_s, s, r;
+ struct rusage ru;
+ int ret;
+
+ tv_then = xclock_now (CLOCK_REALTIME);
+ /* Busy wait for 1 second. */
+ do
+ {
+ tv_now = xclock_now (CLOCK_REALTIME);
+ r = timespec_sub (tv_now, tv_then);
+ } while ( r.tv_sec != TST_GETRUSAGE_TIMEOUT );
+
+ ret = getrusage (RUSAGE_SELF, &ru);
+ if (ret == -1)
+ FAIL_EXIT1 ("getrusage failed: %m\n");
+
+ gru_u = make_timespec (ru.ru_utime.tv_sec, ru.ru_utime.tv_usec * 1000);
+ gru_s = make_timespec (ru.ru_stime.tv_sec, ru.ru_stime.tv_usec * 1000);
+ s = timespec_add (gru_u, gru_s);
+
+ TEST_COMPARE (support_timespec_check_in_range
+ ((struct timespec) { 1, 0 }, s, 0.8, 1.2), 1);
+
+ return 0;
+}
+
+#include <support/test-driver.c>