When timer_create() fails on a bootime or realtime clock, setup_timer()
returns 0 as if timer has been set. Callers wait forever for the timer
to expire.

This hang is seen on a system that doesn't have support for:

CLOCK_REALTIME_ALARM   ABSTIME missing CAP_WAKE_ALARM? : [UNSUPPORTED]

Test hangs waiting for a timer that hasn't been set to expire. Fix
setup_timer() to return 1, add handling in callers to detect the
unsupported case and return 0 without waiting to not fail the test.
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

do_timer_oneshot() uses select() as a timer with FD_SETSIZE and readfs
is cleared with FD_ZERO without FD_SET.

When stdout and stderr are redirected, the test hangs in select forever.
Fix the problem calling select() with readfds empty and nfds zero. This
is sufficient for using select() for timer.

With this fix "./set-timer-lat > /dev/null 2>&1" no longer hangs.
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Acked-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

There is no need to keep timers tests in sync with external timers
repo. Drop support for !KTEST to support for building and running
timers tests without kselftest framework.

Reference: https://lkml.org/lkml/2017/8/10/952Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>
Acked-by: NJohn Stultz <john.stultz@linaro.org>

These testcases are motivated by a recent alarmtimer regression, which
caused one-shot CLOCK_{BOOTTIME,REALTIME}_ALARM timers to become
periodic timers.

The new testcases are very similar to the existing testcases for
repeating timers.  But rather than waiting for 5 alarms, they wait for 5
seconds and verify that the alarm fired exactly once.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

Rather than printing an error inside the alarm signal handler, set a
flag that we check later.  This keeps the test from spamming the console
every time the alarm fires early.  It also fixes the test exiting with
error code 0 if this was the only test failure.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>

The set-timer-lat test fails when testing CLOCK_BOOTTIME_ALARM
or CLOCK_REALTIME_ALARM when the user isn't running as root or
with CAP_WAKE_ALARM.

So this patch improves the error checking so we report the
issue more clearly and continue rather then reporting a failure.

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

For the default run_timers target, the timers tests takes the
majority of kselftests runtime.

So this patch reduces the default runtime for inconsistentcy-check
and set-timer-lat, which reduced the runtime almost in half.

Before:	11m48.629s
After:	6m47.723s

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>

Add my set-timer-lat test from the timetest suite. This
test checks the latency from set_timer and reports if
any are unreasonable (>40ms).

Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NShuah Khan <shuahkh@osg.samsung.com>