Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1221301

Re: [PATCH 2/2][RFC] kselftest: timers: Add adjtick test to validate adjtimex() tick adjustments

Show all headers | View raw

On Tue, Sep 08, 2015 at 10:57:06PM -0700, John Stultz wrote:
> Recently an issue was reported that was difficult to detect except
> by tweaking the adjtimex tick value, and noticing how quickly the
> adjustment took to be made:
> 	https://lkml.org/lkml/2015/9/1/488
> 
> Thus this patch introduces a new test which manipulates the adjtimex
> tick value and validates the results are what we expect.

Great!

> +	ppm = ((long long)tickval * MILLION)/10000 - MILLION;

I think this needs to be based on sysconf(_SC_CLK_TCK) or similar,
since the user-space HZ is not 100 on all archs.

> +	for (tick = 9000; tick < 11000; tick += 250)
> +		if (check_tick_adj(tick)) {

This too.

> +	tx1.tick = 10000;
> +	adjtimex(&tx1);

And this too.

-- 
Miroslav Lichvar
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 2/2][RFC] kselftest: timers: Add adjtick test to validate adjtimex() tick adjustments John Stultz <john.stultz@linaro.org> - 2015-09-09 08:10 +0200
  Re: [PATCH 2/2][RFC] kselftest: timers: Add adjtick test to validate  adjtimex() tick adjustments Miroslav Lichvar <mlichvar@redhat.com> - 2015-09-09 10:40 +0200
    Re: [PATCH 2/2][RFC] kselftest: timers: Add adjtick test to validate  adjtimex() tick adjustments John Stultz <john.stultz@linaro.org> - 2015-09-09 19:20 +0200

csiph-web