Re: lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces)

[Sebastian Andrzej Siewior]

On 2023-11-08 09:04:40 [+0800], kernel test robot wrote:
…
Could you please explain what is wrong here? The code in line 73 has no
percpu reference at all. Or expects an argument.

> sparse warnings: (new ones prefixed by >>)
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got unsigned int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got unsigned int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got unsigned int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got unsigned int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got int [noderef] __percpu *
> >> lib/flex_proportions.c:73:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>    lib/flex_proportions.c:73:9: sparse:     expected void *ptr
>    lib/flex_proportions.c:73:9: sparse:     got int [noderef] __percpu *
>    lib/flex_proportions.c: note: in included file (through include/linux/mmzone.h, include/linux/gfp.h, include/linux/percpu_counter.h, ...):
> 
> vim +73 lib/flex_proportions.c
> 
>     55	
>     56	/*
>     57	 * Declare @periods new periods. It is upto the caller to make sure period
>     58	 * transitions cannot happen in parallel.
>     59	 *
>     60	 * The function returns true if the proportions are still defined and false
>     61	 * if aging zeroed out all events. This can be used to detect whether declaring
>     62	 * further periods has any effect.
>     63	 */
>     64	bool fprop_new_period(struct fprop_global *p, int periods)
>     65	{
>     66		s64 events = percpu_counter_sum(&p->events);
>     67	
>     68		/*
>     69		 * Don't do anything if there are no events.
>     70		 */
>     71		if (events <= 1)
>     72			return false;
>   > 73		preempt_disable_nested();
>     74		write_seqcount_begin(&p->sequence);
>     75		if (periods < 64)
>     76			events -= events >> periods;
>     77		/* Use addition to avoid losing events happening between sum and set */
>     78		percpu_counter_add(&p->events, -events);
>     79		p->period += periods;
>     80		write_seqcount_end(&p->sequence);
>     81		preempt_enable_nested();
>     82	
>     83		return true;
>     84	}
>     85	
> 
Sebastian