On Tue, Nov 30, 2021 at 10:41 PM <andrey.konovalov@xxxxxxxxx> wrote:
>
> From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
>
> This patch separates code for zeroing memory from the code clearing tags
> in post_alloc_hook().
>
> This patch is not useful by itself but makes the simplifications in
> the following patches easier to follow.
>
> This patch does no functional changes.
>
> Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> ---
> mm/page_alloc.c | 18 ++++++++++--------
> 1 file changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 2ada09a58e4b..0561cdafce36 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2406,19 +2406,21 @@ inline void post_alloc_hook(struct page *page, unsigned int order,
> kasan_alloc_pages(page, order, gfp_flags);
> } else {
> bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags);
> + bool init_tags = init && (gfp_flags & __GFP_ZEROTAGS);
>
> kasan_unpoison_pages(page, order, init);
>
> - if (init) {
> - if (gfp_flags & __GFP_ZEROTAGS) {
> - int i;
> + if (init_tags) {
> + int i;
>
> - for (i = 0; i < 1 << order; i++)
> - tag_clear_highpage(page + i);
> - } else {
> - kernel_init_free_pages(page, 1 << order);
> - }
> + for (i = 0; i < 1 << order; i++)
> + tag_clear_highpage(page + i);
> +
> + init = false;
I find this a bit twisted and prone to breakages.
Maybe just check for (init && !init_tags) below?
> }
> +
> + if (init)
> + kernel_init_free_pages(page, 1 << order);
> }
>
> set_page_owner(page, order, gfp_flags);
> --
> 2.25.1
>
--
Alexander Potapenko
Software Engineer
Google Germany GmbH
Erika-Mann-Straße, 33
80636 München
Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
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Sitz der Gesellschaft: Hamburg
