Re: [PATCH 0/4] nolibc: add support for the s390 platform

[Sven Schnelle]

"Paul E. McKenney" <paulmck@xxxxxxxxxx> writes:

> On Tue, Jan 10, 2023 at 05:12:49PM +0100, Willy Tarreau wrote:
>> On Tue, Jan 10, 2023 at 06:53:34AM -0800, Paul E. McKenney wrote:
>> > Here is one of them, based on both the fixes and Sven's s390 support.
>> > Please let me know if you need any other combination.
>> 
>> Thanks, here's the problem:
>> 
>> > 0 getpid = 1                             [OK]
>> > 1 getppid = 0                            [OK]
>> > 3 gettid = 1                             [OK]
>> > 5 getpgid_self = 0                       [OK]
>> > 6 getpgid_bad = -1 ESRCH                 [OK]
>> > 7 kill_0[    1.940442] tsc: Refined TSC clocksource calibration: 2399.981 MHz
>> > [    1.942334] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x229825a5278, max_idle_ns: 440795306804 ns
>> >  = 0                             [OK]
>> > 8 kill_CONT = 0           [    1.944987] clocksource: Switched to clocksource tsc
>> >                [OK]
>> > 9 kill_BADPID = -1 ESRCH                 [OK]
>> (...)
>> 
>> It's clear that "grep -c ^[0-9].*OK" will not count all of them (2 are
>> indeed missing).
>> 
>> We could probably start with "quiet" but that would be against the
>> principle of using this to troubleshoot issues. I think we just stick
>> to the current search of "FAIL" and that as long as a success is
>> reported and the number of successes is within the expected range
>> that could be OK. At least I guess :-/
>
> Huh.  Would it make sense to delay the start of the nolibc testing by a
> few seconds in order to avoid this sort of thing?  Or would that cause
> other problems?

Or define a second serial port (or something similar) in qemu and run the
kernel console on ttyS0, and the init process writes to /dev/ttyS1? So the
output of the test program could be redirected to a file on the host?