Re: [PATCH RESEND v1] mm/memory_hotplug: move debug_pagealloc_map_pages() into online_pages_range()

[Oscar Salvador <osalvador@suse.de>]

On Tue, Dec 03, 2024 at 11:20:50AM +0100, David Hildenbrand wrote:
> In the near future, we want to have a single way to handover PageOffline
> pages to the buddy, whereby they could have:
> 
> (a) Never been exposed to the buddy before: kept PageOffline when onlining
>     the memory block.
> (b) Been allocated from the buddy, for example using
>     alloc_contig_range() to then be set PageOffline,
> 
> Let's start by making generic_online_page() less special compared to

This got me confused for a moment. I'd have said "making
__free_pages_core" less special? As that is where we were calling 
debug_pagealloc_map_pages() if the context  on the context.

> ordinary page freeing (e.g., free_contig_range()), and perform the
> debug_pagealloc_map_pages() call unconditionally, even when the online
> callback might decide to keep the pages offline.
> 
> All pages are already initialized with PageOffline, so nobody touches
> them either way.
> 
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Oscar Salvador <osalvador@suse.de>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Acked-by: Oscar Salvador <osalvador@suse.de>


-- 
Oscar Salvador
SUSE Labs