linux-kernel - Re: [PATCH v1 1/3] mm: pass meminit_context to __free_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZmZ7GgwJw4ucPJaM@localhost.localdomain>
Date: Mon, 10 Jun 2024 06:03:38 +0200
From: Oscar Salvador <osalvador@...e.de>
To: David Hildenbrand <david@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	linux-hyperv@...r.kernel.org, virtualization@...ts.linux.dev,
	xen-devel@...ts.xenproject.org, kasan-dev@...glegroups.com,
	Andrew Morton <akpm@...ux-foundation.org>,
	Mike Rapoport <rppt@...nel.org>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Haiyang Zhang <haiyangz@...rosoft.com>,
	Wei Liu <wei.liu@...nel.org>, Dexuan Cui <decui@...rosoft.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Jason Wang <jasowang@...hat.com>,
	Xuan Zhuo <xuanzhuo@...ux.alibaba.com>,
	Eugenio Pérez <eperezma@...hat.com>,
	Juergen Gross <jgross@...e.com>,
	Stefano Stabellini <sstabellini@...nel.org>,
	Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
	Alexander Potapenko <glider@...gle.com>,
	Marco Elver <elver@...gle.com>, Dmitry Vyukov <dvyukov@...gle.com>
Subject: Re: [PATCH v1 1/3] mm: pass meminit_context to __free_pages_core()

On Fri, Jun 07, 2024 at 11:09:36AM +0200, David Hildenbrand wrote:
> In preparation for further changes, let's teach __free_pages_core()
> about the differences of memory hotplug handling.
> 
> Move the memory hotplug specific handling from generic_online_page() to
> __free_pages_core(), use adjust_managed_page_count() on the memory
> hotplug path, and spell out why memory freed via memblock
> cannot currently use adjust_managed_page_count().
> 
> Signed-off-by: David Hildenbrand <david@...hat.com>

All looks good but I am puzzled with something.

> +	} else {
> +		/* memblock adjusts totalram_pages() ahead of time. */
> +		atomic_long_add(nr_pages, &page_zone(page)->managed_pages);
> +	}

You say that memblock adjusts totalram_pages ahead of time, and I guess
you mean in memblock_free_all()

 pages = free_low_memory_core_early()
 totalram_pages_add(pages);

but that is not ahead, it looks like it is upading __after__ sending
them to buddy?


-- 
Oscar Salvador
SUSE Labs