Re: [PATCHv3 04/24] rmap: add argument to charge compound page

Rik van Riel
2015-02-12T21:18:07Z

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On 02/12/2015 11:18 AM, Kirill A. Shutemov wrote:

> +++ b/include/linux/rmap.h @@ -168,16 +168,24 @@ static inline void
> anon_vma_merge(struct vm_area_struct *vma,
>
> struct anon_vma *page_get_anon_vma(struct page *page);
>
> +/* flags for do_page_add_anon_rmap() */ +enum { + RMAP_EXCLUSIVE =
> 1, + RMAP_COMPOUND = 2, +};

Always a good idea to name things. However, "exclusive" is
not that clear to me. Given that the argument is supposed
to indicate whether we map a single or a compound page,
maybe the names in the enum could just be SINGLE and COMPOUND?

Naming the enum should make it clear enough what it does:

enum rmap_page {
SINGLE = 0,
COMPOUND
}

> +++ b/kernel/events/uprobes.c @@ -183,7 +183,7 @@ static int
> __replace_page(struct vm_area_struct *vma, unsigned long addr, goto
> unlock;
>
> get_page(kpage); - page_add_new_anon_rmap(kpage, vma, addr); +
> page_add_new_anon_rmap(kpage, vma, addr, false);
> mem_cgroup_commit_charge(kpage, memcg, false);
> lru_cache_add_active_or_unevictable(kpage, vma);

Would it make sense to use the name in the argument to that function,
too?

I often find it a lot easier to see what things do if they use symbolic
names, rather than by trying to remember what each boolean argument to
a function does.

- --
All rights reversed
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