linux-kernel - Re: [PATCH v9 3/8] mm: Move set/get_pcppage

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]

Date:   Mon, 9 Sep 2019 10:22:29 +0200
From:   David Hildenbrand <david@...hat.com>
To:     Alexander Duyck <alexander.duyck@...il.com>,
        virtio-dev@...ts.oasis-open.org, kvm@...r.kernel.org,
        mst@...hat.com, catalin.marinas@....com, dave.hansen@...el.com,
        linux-kernel@...r.kernel.org, willy@...radead.org,
        mhocko@...nel.org, linux-mm@...ck.org, akpm@...ux-foundation.org,
        will@...nel.org, linux-arm-kernel@...ts.infradead.org,
        osalvador@...e.de
Cc:     yang.zhang.wz@...il.com, pagupta@...hat.com,
        konrad.wilk@...cle.com, nitesh@...hat.com, riel@...riel.com,
        lcapitulino@...hat.com, wei.w.wang@...el.com, aarcange@...hat.com,
        ying.huang@...el.com, pbonzini@...hat.com,
        dan.j.williams@...el.com, fengguang.wu@...el.com,
        alexander.h.duyck@...ux.intel.com, kirill.shutemov@...ux.intel.com
Subject: Re: [PATCH v9 3/8] mm: Move set/get_pcppage_migratetype to mmzone.h

On 07.09.19 19:25, Alexander Duyck wrote:
> From: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
> 
> In order to support page reporting it will be necessary to store and
> retrieve the migratetype of a page. To enable that I am moving the set and
> get operations for pcppage_migratetype into the mm/internal.h header so
> that they can be used outside of the page_alloc.c file.
> 
> Reviewed-by: Dan Williams <dan.j.williams@...el.com>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@...ux.intel.com>
> ---
>  mm/internal.h   |   18 ++++++++++++++++++
>  mm/page_alloc.c |   18 ------------------
>  2 files changed, 18 insertions(+), 18 deletions(-)
> 
> diff --git a/mm/internal.h b/mm/internal.h
> index 0d5f720c75ab..e4a1a57bbd40 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -549,6 +549,24 @@ static inline bool is_migrate_highatomic_page(struct page *page)
>  	return get_pageblock_migratetype(page) == MIGRATE_HIGHATOMIC;
>  }
>  
> +/*
> + * A cached value of the page's pageblock's migratetype, used when the page is
> + * put on a pcplist. Used to avoid the pageblock migratetype lookup when
> + * freeing from pcplists in most cases, at the cost of possibly becoming stale.
> + * Also the migratetype set in the page does not necessarily match the pcplist
> + * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
> + * other index - this ensures that it will be put on the correct CMA freelist.
> + */
> +static inline int get_pcppage_migratetype(struct page *page)
> +{
> +	return page->index;
> +}
> +
> +static inline void set_pcppage_migratetype(struct page *page, int migratetype)
> +{
> +	page->index = migratetype;
> +}
> +
>  void setup_zone_pageset(struct zone *zone);
>  extern struct page *alloc_new_node_page(struct page *page, unsigned long node);
>  #endif	/* __MM_INTERNAL_H */
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 4e4356ba66c7..a791f2baeeeb 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -185,24 +185,6 @@ static int __init early_init_on_free(char *buf)
>  }
>  early_param("init_on_free", early_init_on_free);
>  
> -/*
> - * A cached value of the page's pageblock's migratetype, used when the page is
> - * put on a pcplist. Used to avoid the pageblock migratetype lookup when
> - * freeing from pcplists in most cases, at the cost of possibly becoming stale.
> - * Also the migratetype set in the page does not necessarily match the pcplist
> - * index, e.g. page might have MIGRATE_CMA set but be on a pcplist with any
> - * other index - this ensures that it will be put on the correct CMA freelist.
> - */
> -static inline int get_pcppage_migratetype(struct page *page)
> -{
> -	return page->index;
> -}
> -
> -static inline void set_pcppage_migratetype(struct page *page, int migratetype)
> -{
> -	page->index = migratetype;
> -}
> -
>  #ifdef CONFIG_PM_SLEEP
>  /*
>   * The following functions are used by the suspend/hibernate code to temporarily
> 
> 

Still have to understand in detail how this will be used, but the change
certainly looks ok :)

Acked-by: David Hildenbrand <david@...hat.com>

-- 

Thanks,

David / dhildenb