Re: [PATCH v2 1/2] driver/base: Optimize memory block registration to reduce boot time

[Donet Tom]

On 4/30/25 1:08 PM, Oscar Salvador wrote:
> On Mon, Apr 28, 2025 at 10:33:46PM +0530, Donet Tom wrote:
> > During node device initialization, `memory blocks` are registered under
> > each NUMA node. The `memory blocks` to be registered are identified using
> > the node’s start and end PFNs, which are obtained from the node's pg_data
> Hi Donet,
>
> > Test Results on My system with 32TB RAM
> > =======================================
> > 1. Boot time with CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled.
> >
> > Without this patch
> > ------------------
> > Startup finished in 1min 16.528s (kernel)
> >
> > With this patch
> > ---------------
> > Startup finished in 17.236s (kernel) - 78% Improvement
> That is pretty impressive.
>
> > +void register_memory_blocks_under_node_early(int nid)
> > +{
> > +	struct memblock_region *r;
> > +	unsigned long start_block_id;
> > +	unsigned long end_block_id;
> > +	struct memory_block *mem;
> > +	unsigned long block_id;
> > +
> > +	for_each_mem_region(r) {
> > +		if (r->nid == nid) {
> > +			start_block_id = phys_to_block_id(r->base);
> > +			end_block_id = phys_to_block_id(r->base + r->size - 1);
> > +
> > +			for (block_id = start_block_id; block_id <= end_block_id; block_id++) {
> > +				mem = find_memory_block_by_id(block_id);
> > +				if (!mem)
> > +					continue;
> I would just mention what David already said here, reduce identation,
> and maybe declare the variables where they are needed. It might be clearer.


Sure, I will change it.

> > +
> > +				do_register_memory_block_under_node(nid, mem, MEMINIT_EARLY);
> > +				put_device(&mem->dev);
> I will comment on the "context" on patch#2.
>
> > +void register_memory_blocks_under_node_early(int nid);
> static void ... ?

Yes, We can make it as static. I will add it in next version.


Thanks
Donet


>