linux-kernel - Re: [RFC v3 1/3] mm: add tracepoint for scanning 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]

Date:	Tue, 14 Jul 2015 00:06:46 +0300
From:	"Kirill A. Shutemov" <kirill@...temov.name>
To:	Ebru Akagunduz <ebru.akagunduz@...il.com>
Cc:	linux-mm@...ck.org, akpm@...ux-foundation.org,
	kirill.shutemov@...ux.intel.com, n-horiguchi@...jp.nec.com,
	aarcange@...hat.com, riel@...hat.com, iamjoonsoo.kim@....com,
	xiexiuqi@...wei.com, gorcunov@...nvz.org,
	linux-kernel@...r.kernel.org, mgorman@...e.de, rientjes@...gle.com,
	vbabka@...e.cz, aneesh.kumar@...ux.vnet.ibm.com, hughd@...gle.com,
	hannes@...xchg.org, mhocko@...e.cz, boaz@...xistor.com,
	raindel@...lanox.com
Subject: Re: [RFC v3 1/3] mm: add tracepoint for scanning pages

On Mon, Jul 13, 2015 at 11:28:02PM +0300, Ebru Akagunduz wrote:
> Using static tracepoints, data of functions is recorded.
> It is good to automatize debugging without doing a lot
> of changes in the source code.
> 
> This patch adds tracepoint for khugepaged_scan_pmd,
> collapse_huge_page and __collapse_huge_page_isolate.
> 
> Signed-off-by: Ebru Akagunduz <ebru.akagunduz@...il.com>
> Acked-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
> Acked-by: Rik van Riel <riel@...hat.com>
> ---
> Changes in v2:
>  - Nothing changed
> 
> Changes in v3:
>  - Print page address instead of vm_start (Vlastimil Babka)
>  - Define constants to specify exact tracepoint result (Vlastimil Babka)
>  
> 
>  include/linux/mm.h                 |  18 ++++++
>  include/trace/events/huge_memory.h | 100 ++++++++++++++++++++++++++++++++
>  mm/huge_memory.c                   | 114 +++++++++++++++++++++++++++----------
>  3 files changed, 203 insertions(+), 29 deletions(-)
>  create mode 100644 include/trace/events/huge_memory.h
> 
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 7f47178..bf341c0 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -21,6 +21,24 @@
>  #include <linux/resource.h>
>  #include <linux/page_ext.h>
>  
> +#define MM_PMD_NULL		0
> +#define MM_EXCEED_NONE_PTE	3
> +#define MM_PTE_NON_PRESENT	4
> +#define MM_PAGE_NULL		5
> +#define MM_SCAN_ABORT		6
> +#define MM_PAGE_COUNT		7
> +#define MM_PAGE_LRU		8
> +#define MM_ANY_PROCESS		0
> +#define MM_VMA_NULL		2
> +#define MM_VMA_CHECK		3
> +#define MM_ADDRESS_RANGE	4
> +#define MM_PAGE_LOCK		2
> +#define MM_SWAP_CACHE_PAGE	6
> +#define MM_ISOLATE_LRU_PAGE	7
> +#define MM_ALLOC_HUGE_PAGE_FAIL	6
> +#define MM_CGROUP_CHARGE_FAIL	7
> +#define MM_COLLAPSE_ISOLATE_FAIL 5
> +

These magic numbers looks very random. What's logic behind?

-- 
 Kirill A. Shutemov
--
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/