| 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
| ||
|
Message-ID: <CALYGNiMEytHuND37f+hNdMKqCPzN0k_uha6CaeL_fyzrj-obNQ@mail.gmail.com>
Date: Wed, 10 Dec 2014 21:06:05 +0400
From: Konstantin Khlebnikov <koct9i@...il.com>
To: "Wang, Yalin" <Yalin.Wang@...ymobile.com>
Cc: "Kirill A. Shutemov" <kirill@...temov.name>,
Andrew Morton <akpm@...ux-foundation.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"linux-mm@...ck.org" <linux-mm@...ck.org>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"n-horiguchi@...jp.nec.com" <n-horiguchi@...jp.nec.com>
Subject: Re: [RFC V5] mm:add KPF_ZERO_PAGE flag for /proc/kpageflags
On Tue, Dec 9, 2014 at 6:24 AM, Wang, Yalin <Yalin.Wang@...ymobile.com> wrote:
> This patch add KPF_ZERO_PAGE flag for zero_page,
> so that userspace process can notice zero_page from
> /proc/kpageflags, and then do memory analysis more accurately.
>
> Signed-off-by: Yalin Wang <yalin.wang@...ymobile.com>
Ack. Looks good.
> ---
> Documentation/vm/pagemap.txt | 8 ++++++++
> fs/proc/page.c | 16 +++++++++++++---
> include/linux/huge_mm.h | 12 ++++++++++++
> include/uapi/linux/kernel-page-flags.h | 1 +
> mm/huge_memory.c | 7 +------
> tools/vm/page-types.c | 1 +
> 6 files changed, 36 insertions(+), 9 deletions(-)
>
> diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt
> index 5948e45..6fbd55e 100644
> --- a/Documentation/vm/pagemap.txt
> +++ b/Documentation/vm/pagemap.txt
> @@ -62,6 +62,8 @@ There are three components to pagemap:
> 20. NOPAGE
> 21. KSM
> 22. THP
> + 23. BALLOON
> + 24. ZERO_PAGE
>
> Short descriptions to the page flags:
>
> @@ -102,6 +104,12 @@ Short descriptions to the page flags:
> 22. THP
> contiguous pages which construct transparent hugepages
>
> +23. BALLOON
> + balloon compaction page
> +
> +24. ZERO_PAGE
> + zero page for pfn_zero or huge_zero page
> +
> [IO related page flags]
> 1. ERROR IO error occurred
> 3. UPTODATE page has up-to-date data
> diff --git a/fs/proc/page.c b/fs/proc/page.c
> index 1e3187d..7eee2d8 100644
> --- a/fs/proc/page.c
> +++ b/fs/proc/page.c
> @@ -5,6 +5,7 @@
> #include <linux/ksm.h>
> #include <linux/mm.h>
> #include <linux/mmzone.h>
> +#include <linux/huge_mm.h>
> #include <linux/proc_fs.h>
> #include <linux/seq_file.h>
> #include <linux/hugetlb.h>
> @@ -121,9 +122,18 @@ u64 stable_page_flags(struct page *page)
> * just checks PG_head/PG_tail, so we need to check PageLRU/PageAnon
> * to make sure a given page is a thp, not a non-huge compound page.
> */
> - else if (PageTransCompound(page) && (PageLRU(compound_head(page)) ||
> - PageAnon(compound_head(page))))
> - u |= 1 << KPF_THP;
> + else if (PageTransCompound(page)) {
> + struct page *head = compound_head(page);
> +
> + if (PageLRU(head) || PageAnon(head))
> + u |= 1 << KPF_THP;
> + else if (is_huge_zero_page(head)) {
> + u |= 1 << KPF_ZERO_PAGE;
> + u |= 1 << KPF_THP;
> + }
> + } else if (is_zero_pfn(page_to_pfn(page)))
> + u |= 1 << KPF_ZERO_PAGE;
> +
>
> /*
> * Caveats on high order pages: page->_count will only be set
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index ad9051b..f10b20f 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -157,6 +157,13 @@ static inline int hpage_nr_pages(struct page *page)
> extern int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_struct *vma,
> unsigned long addr, pmd_t pmd, pmd_t *pmdp);
>
> +extern struct page *huge_zero_page;
> +
> +static inline bool is_huge_zero_page(struct page *page)
> +{
> + return ACCESS_ONCE(huge_zero_page) == page;
> +}
> +
> #else /* CONFIG_TRANSPARENT_HUGEPAGE */
> #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
> #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; })
> @@ -206,6 +213,11 @@ static inline int do_huge_pmd_numa_page(struct mm_struct *mm, struct vm_area_str
> return 0;
> }
>
> +static inline bool is_huge_zero_page(struct page *page)
> +{
> + return false;
> +}
> +
> #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>
> #endif /* _LINUX_HUGE_MM_H */
> diff --git a/include/uapi/linux/kernel-page-flags.h b/include/uapi/linux/kernel-page-flags.h
> index 2f96d23..a6c4962 100644
> --- a/include/uapi/linux/kernel-page-flags.h
> +++ b/include/uapi/linux/kernel-page-flags.h
> @@ -32,6 +32,7 @@
> #define KPF_KSM 21
> #define KPF_THP 22
> #define KPF_BALLOON 23
> +#define KPF_ZERO_PAGE 24
>
>
> #endif /* _UAPILINUX_KERNEL_PAGE_FLAGS_H */
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index de98415..d7bc7a5 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -171,12 +171,7 @@ static int start_khugepaged(void)
> }
>
> static atomic_t huge_zero_refcount;
> -static struct page *huge_zero_page __read_mostly;
> -
> -static inline bool is_huge_zero_page(struct page *page)
> -{
> - return ACCESS_ONCE(huge_zero_page) == page;
> -}
> +struct page *huge_zero_page __read_mostly;
>
> static inline bool is_huge_zero_pmd(pmd_t pmd)
> {
> diff --git a/tools/vm/page-types.c b/tools/vm/page-types.c
> index 264fbc2..8bdf16b 100644
> --- a/tools/vm/page-types.c
> +++ b/tools/vm/page-types.c
> @@ -133,6 +133,7 @@ static const char * const page_flag_names[] = {
> [KPF_KSM] = "x:ksm",
> [KPF_THP] = "t:thp",
> [KPF_BALLOON] = "o:balloon",
> + [KPF_ZERO_PAGE] = "z:zero_page",
>
> [KPF_RESERVED] = "r:reserved",
> [KPF_MLOCKED] = "m:mlocked",
> --
> 2.1.3
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists