Re: [RFC PATCH v2 11/19] mm/sparsemem: Use alloc_table() for table allocations

From: Edgecombe, Rick P
Date: Tue Aug 31 2021 - 14:25:31 EST


On Tue, 2021-08-31 at 11:55 +0300, Mike Rapoport wrote:
> On Mon, Aug 30, 2021 at 04:59:19PM -0700, Rick Edgecombe wrote:
<trim>
> > -static void * __meminit vmemmap_alloc_block_zero(unsigned long
> > size, int node)
> > +static void * __meminit vmemmap_alloc_table(int node)
> > {
> > - void *p = vmemmap_alloc_block(size, node);
> > + void *p;
> > + if (slab_is_available()) {
> > + struct page *page = alloc_table_node(GFP_KERNEL |
> > __GFP_ZERO, node);
>
> This change removes __GFP_RETRY_MAYFAIL|__GFP_NOWARN from the
> original gfp
> vmemmap_alloc_block() used.
Oh, yea good point. Hmm, I guess grouped pages could be aware of that
flag too. Would be a small addition, but it starts to grow
unfortunately.

> Not sure __GFP_RETRY_MAYFAIL is really needed in
> vmemmap_alloc_block_zero()
> at the first place, though.
Looks like due to a real issue:
055e4fd96e95b0eee0d92fd54a26be7f0d3bcad0

I think it should not affect PKS tables for now, so maybe I can make
separate logic instead. I'll look into it. Thanks.
>
> More broadly, maybe it makes sense to split boot time and memory
> hotplug
> paths and use pxd_alloc() for the latter.
>
> > +
> > + if (!page)
> > + return NULL;
> > + return page_address(page);
> > + }
> >
> > + p = __earlyonly_bootmem_alloc(node, PAGE_SIZE, PAGE_SIZE,
> > __pa(MAX_DMA_ADDRESS));
>
> Opportunistically rename to __earlyonly_memblock_alloc()? ;-)
>
Heh, I can. Just grepping, there are several other instances of
foo_bootmem() only calling foo_memblock() pattern scattered about. Or
maybe I'm missing the distinction.

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