Re: [patch] suspend/resume self-test

From: Ingo Molnar
Date: Tue Feb 19 2008 - 09:40:45 EST



* David Brownell <david-b@xxxxxxxxxxx> wrote:

> > And, at least to me, there seems to be a rather apparent correlation
> > between "suspend/resume regressions caught as early as possible" and
> > the future, desired state of: "STR working sanely on x86" ;-)
>
> Thing is, this will catch not just regressions ... but cases where STR
> never worked in the first place. Video problems, etc. Also various
> system startup races, as in the PCMCIA and MMC/SD/SDIO cases I noted.

yes, but that's not your problem, that's the STR folks' problem.

> Right, and the best way to ensure that it's only *regressions* that
> break things is to expect someone to have configured the kernel
> command line appropriately (in grub or whatever).

a simple .config flag is perfectly fine for that, as long as it's
default disabled and properly demarked. We have literally _dozens_ of
"dangerous" test options and _nobody_ complains about them being
dangerous ... They do their primary job of triggering bugs sooner,
faster and harder, resulting in bugs getting fixed sooner, faster and
harder.

> Another way to achieve that is to include the test code based on one
> config option, and change the test *mode* based on another one. That
> way a distro could include that in standard kernels with "no test"
> mode as the default, but it would be easy to enable only for oneshot
> tests or field troubleshooting ... while developers could turn on the
> more dangerous "always test STR" (or standby, or hibernate) mode, if
> they were helping to find and fix problems surfaced by such tests.

no distro would enable this option, it just adds a needless 5-6 seconds
delay to the bootup, and a needless "s2ram blows up sooner than it
should" risk. _I_ want to enable this option, and want to see it trigger
more often than just once out of a hundred randconfig setups.

really, you are making rookie mistakes in this area and you are doing
injustice to the code you wrote and maintain :-) As i said it before,
externally it looks like as if you intentionally avoided your code from
being used, from people who _want_ to use your code. _I_ had to fight
for almost an hour (!) until i figured out the zillions of .config
variants that were finally able to get my test-system to boot-time
suspend and resume all by itself. It's totally non-obvious. As far as
the general Linux community goes, it's almost as if your code did not
even exist, so well hidden and obscured it is.

Ingo
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