Re: [PATCH 3/3] mm: move mirrored memory specific code outside of memmap_init_zone

From: Andrew Morton
Date: Tue Jul 24 2018 - 21:18:06 EST


On Tue, 24 Jul 2018 19:55:20 -0400 Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> wrote:

> memmap_init_zone, is getting complex, because it is called from different
> contexts: hotplug, and during boot, and also because it must handle some
> architecture quirks. One of them is mirroed memory.
>
> Move the code that decides whether to skip mirrored memory outside of
> memmap_init_zone, into a separate function.

Conflicts a bit with the page_alloc.c hunk from
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_alloc-remain-memblock_next_valid_pfn-on-arm-arm64.patch. Please check my fixup:

void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
unsigned long start_pfn, enum memmap_context context,
struct vmem_altmap *altmap)
{
unsigned long pfn, end_pfn = start_pfn + size;
struct page *page;

if (highest_memmap_pfn < end_pfn - 1)
highest_memmap_pfn = end_pfn - 1;

/*
* Honor reservation requested by the driver for this ZONE_DEVICE
* memory
*/
if (altmap && start_pfn == altmap->base_pfn)
start_pfn += altmap->reserve;

for (pfn = start_pfn; pfn < end_pfn; pfn++) {
/*
* There can be holes in boot-time mem_map[]s handed to this
* function. They do not exist on hotplugged memory.
*/
if (context == MEMMAP_EARLY) {
if (!early_pfn_valid(pfn)) {
pfn = next_valid_pfn(pfn) - 1;
continue;
}
if (!early_pfn_in_nid(pfn, nid))
continue;
if (overlap_memmap_init(zone, &pfn))
continue;
if (defer_init(nid, pfn, end_pfn))
break;
}

page = pfn_to_page(pfn);
__init_single_page(page, pfn, zone, nid);
if (context == MEMMAP_HOTPLUG)
SetPageReserved(page);

/*
* Mark the block movable so that blocks are reserved for
* movable at startup. This will force kernel allocations
* to reserve their blocks rather than leaking throughout
* the address space during boot when many long-lived
* kernel allocations are made.
*
* bitmap is created for zone's valid pfn range. but memmap
* can be created for invalid pages (for alignment)
* check here not to call set_pageblock_migratetype() against
* pfn out of zone.
*/
if (!(pfn & (pageblock_nr_pages - 1))) {
set_pageblock_migratetype(page, MIGRATE_MOVABLE);
cond_resched();
}
}
}