Re: [PATCH v3] mm: cma: support sysfs

[Andrew Morton]

On Wed, 3 Mar 2021 17:38:12 -0800 Minchan Kim <minchan@xxxxxxxxxx> wrote:

> > >  #endif
> > >  	char name[CMA_MAX_NAME];
> > > +#ifdef CONFIG_CMA_SYSFS
> > > +	struct cma_stat	*stat;
> > > +#endif
> > >  };
> > 
> > Why aren't the stat fields simply placed directly into struct cma_stat?
> 
> It have a related long discussion.
> https://lore.kernel.org/linux-mm/YCIoHBGELFWAyfMi@xxxxxxxxx/
> https://lore.kernel.org/linux-mm/YCLLKDEQ4NYqb5Y5@xxxxxxxxx/
> 
> TLDR - Greg really want to see kobject stuff working as dynamic
> property.

Please add to changelog?

> > 
> > ?
> > 
> > > +	if (!cma_stats) {
> > > +		pr_err("failed to create cma_stats\n");
> > 
> > Probably unneeded - the ENOMEM stack backtrace will point straight here.
> 
> I failed to find the point you mentioned to print backtrace.
> Where code do you mean to dump the backtrace?

The thing which __GFP_NOWARN disables.