Re: [PATCH] locktorture: make verbose writable and control stats print

[Shi, Yang]

On 4/15/2016 4:26 PM, Paul E. McKenney wrote:
> On Fri, Apr 15, 2016 at 01:28:11PM -0700, Yang Shi wrote:
> > When building locktorture test into kernel image, it keeps printing out
> > stats information even though there is no lock type specified.
> >
> > There is already verbose parameter to control print, but it is read-only,
> > so it can't be changed at runtime. Make verbose read-write and control
> > stats print.
> >
> > Signed-off-by: Yang Shi <yang.shi@xxxxxxxxxx>
>
> Interesting change!
>
> But just out of curiosity, when you boot with locktorture built in,
> do you specify the shutdown_secs boot parameter?  If so, another

No, just use the default value, which is 0 for shutdown_secs.

> approach would be to shutdown immediately upon detecting an error
> during initialization.

In my case, it looks there is not error involved.

> If not, I would like to know more about your use case.

In my test, I just built locktorture test into kernel instead of a 
module then check how it behaves, no specific purpose.

It sounds like not a normal approach to use it.

Thanks,
Yang

> 							Thanx, Paul
>
> > ---
> >   include/linux/torture.h      |  2 ++
> >   kernel/locking/locktorture.c | 11 +++++++----
> >   2 files changed, 9 insertions(+), 4 deletions(-)
> >
> > diff --git a/include/linux/torture.h b/include/linux/torture.h
> > index 7759fc3..86d6e54 100644
> > --- a/include/linux/torture.h
> > +++ b/include/linux/torture.h
> > @@ -48,6 +48,8 @@
> >   	do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0)
> >   #define VERBOSE_TOROUT_ERRSTRING(s) \
> >   	do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0)
> > +#define VERBOSE_STRING(s) \
> > +	do { if (verbose) pr_alert("%s", s); } while (0)
> >
> >   /* Definitions for online/offline exerciser. */
> >   int torture_onoff_init(long ooholdoff, long oointerval);
> > diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> > index 8ef1919..d9838a3 100644
> > --- a/kernel/locking/locktorture.c
> > +++ b/kernel/locking/locktorture.c
> > @@ -55,8 +55,11 @@ torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
> >   torture_param(int, stat_interval, 60,
> >   	     "Number of seconds between stats printk()s");
> >   torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
> > -torture_param(bool, verbose, true,
> > -	     "Enable verbose debugging printk()s");
> > +
> > +static bool verbose = true;
> > +module_param(verbose, bool, 0644);
> > +MODULE_PARM_DESC(verbose,
> > +		 "Enable verbose debugging printk()s");
> >
> >   static char *torture_type = "spin_lock";
> >   module_param(torture_type, charp, 0444);
> > @@ -693,7 +696,7 @@ static void lock_torture_stats_print(void)
> >   	}
> >
> >   	__torture_print_stats(buf, cxt.lwsa, true);
> > -	pr_alert("%s", buf);
> > +	VERBOSE_STRING(buf);
> >   	kfree(buf);
> >
> >   	if (cxt.cur_ops->readlock) {
> > @@ -705,7 +708,7 @@ static void lock_torture_stats_print(void)
> >   		}
> >
> >   		__torture_print_stats(buf, cxt.lrsa, false);
> > -		pr_alert("%s", buf);
> > +		VERBOSE_STRING(buf);
> >   		kfree(buf);
> >   	}
> >   }
> > --
> > 2.0.2