Re: [EDAC ABI v13 24/25] edac: change the mem allocation scheme to make Documentation/kobject.txt happy

[Joe Perches <joe@perches.com>]

On Mon, 2012-04-16 at 17:38 -0300, Mauro Carvalho Chehab wrote:
> Kernel kobjects have rigid rules: each container object should be
> dynamically allocated, and can't be allocated into a single kmalloc.
> 
> EDAC never obeyed this rule: it has a single malloc function that
> allocates all needed data into a single kzalloc.
> 
> As this is not accepted anymore, change the allocation schema of the
> EDAC *_info structs to enforce this Kernel standard.
[]
> diff --git a/drivers/edac/amd64_edac.c b/drivers/edac/amd64_edac.c
[]
> @@ -2228,9 +2228,9 @@ static int init_csrows(struct mem_ctl_info *mci)
>  			edac_mode = EDAC_NONE;
>  
>  		for (j = 0; j < pvt->channel_count; j++) {
> -			csrow->channels[j].dimm->mtype = mtype;
> -			csrow->channels[j].dimm->edac_mode = edac_mode;
> -			csrow->channels[j].dimm->nr_pages = nr_pages;
> +			csrow->channels[j]->dimm->mtype = mtype;
> +			csrow->channels[j]->dimm->edac_mode = edac_mode;
> +			csrow->channels[j]->dimm->nr_pages = nr_pages;

It might be better to use an automatic for
	typeof foo dimm = csrow->channels[j]->dimm;
	dimm->mtype = mtype;
	etc...
[]
> @@ -293,39 +286,56 @@ struct mem_ctl_info *edac_mc_alloc(unsigned edac_index,
>  	mci->mem_is_per_rank = per_rank;
>  
>  	/*
> -	 * Fills the csrow struct
> +	 * Alocate and fill the csrow/channels structs
>  	 */
> +	mci->csrows = kzalloc(sizeof(*mci->csrows) * tot_csrows, GFP_KERNEL);

kcalloc

[]
> +		csr->channels = kzalloc(sizeof(*csr->channels) * tot_cschannels,
> +					GFP_KERNEL);

here too

> @@ -391,7 +401,31 @@ struct mem_ctl_info *edac_mc_alloc(unsigned edac_index,
>  
>  	trace_hw_event_init("edac", (unsigned)edac_index);
>  
> +	debugf1("EDAC MCI allocated\n");
>  	return mci;
> +
> +error:
> +	debugf1("Failed to allocate one or more EDAC MCI structs\n");

Generally, it's not necessary to have specific "OOM" messages
as allocations without GFP_NOWARN do dump_stack()s