2013-09-05 07:58:40

by Jianguo Wu

[permalink] [raw]
Subject: [PATCH v2] mm/thp: fix stale comments of transparent_hugepage_flags

Changelog:
*v1 -> v2: also update the stale comments about default transparent
hugepage support pointed by Wanpeng Li.

Since commit 13ece886d9(thp: transparent hugepage config choice),
transparent hugepage support is disabled by default, and
TRANSPARENT_HUGEPAGE_ALWAYS is configured when TRANSPARENT_HUGEPAGE=y.

And since commit d39d33c332(thp: enable direct defrag), defrag is
enable for all transparent hugepage page faults by default, not only in
MADV_HUGEPAGE regions.

Signed-off-by: Jianguo Wu <[email protected]>
---
mm/huge_memory.c | 12 ++++++------
1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a92012a..0e42a70 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -26,12 +26,12 @@
#include <asm/pgalloc.h>
#include "internal.h"

-/*
- * By default transparent hugepage support is enabled for all mappings
- * and khugepaged scans all mappings. Defrag is only invoked by
- * khugepaged hugepage allocations and by page faults inside
- * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived
- * allocations.
+/* By default transparent hugepage support is disabled in order that avoid
+ * to risk increase the memory footprint of applications without a guaranteed
+ * benefit. When transparent hugepage support is enabled, is for all mappings,
+ * and khugepaged scans all mappings.
+ * Defrag is invoked by khugepaged hugepage allocations and by page faults
+ * for all hugepage allocations.
*/
unsigned long transparent_hugepage_flags __read_mostly =
#ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
--
1.7.1


2013-09-05 08:44:54

by Jianguo Wu

[permalink] [raw]
Subject: Re: [PATCH v2] mm/thp: fix stale comments of transparent_hugepage_flags

Hi Wanpeng,
Thanks for your review, but this patch has minor format problem, please see below.
Please review the resend one, thanks.

Thanks,
Jianguo Wu

On 2013/9/5 16:09, Wanpeng Li wrote:

> On Thu, Sep 05, 2013 at 03:57:47PM +0800, Jianguo Wu wrote:
>> Changelog:
>> *v1 -> v2: also update the stale comments about default transparent
>> hugepage support pointed by Wanpeng Li.
>>
>> Since commit 13ece886d9(thp: transparent hugepage config choice),
>> transparent hugepage support is disabled by default, and
>> TRANSPARENT_HUGEPAGE_ALWAYS is configured when TRANSPARENT_HUGEPAGE=y.
>>
>> And since commit d39d33c332(thp: enable direct defrag), defrag is
>> enable for all transparent hugepage page faults by default, not only in
>> MADV_HUGEPAGE regions.
>>
>
> Reviewed-by: Wanpeng Li <[email protected]>
>
>> Signed-off-by: Jianguo Wu <[email protected]>
>> ---
>> mm/huge_memory.c | 12 ++++++------
>> 1 files changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
>> index a92012a..0e42a70 100644
>> --- a/mm/huge_memory.c
>> +++ b/mm/huge_memory.c
>> @@ -26,12 +26,12 @@
>> #include <asm/pgalloc.h>
>> #include "internal.h"
>>
>> -/*
>> - * By default transparent hugepage support is enabled for all mappings
>> - * and khugepaged scans all mappings. Defrag is only invoked by
>> - * khugepaged hugepage allocations and by page faults inside
>> - * MADV_HUGEPAGE regions to avoid the risk of slowing down short lived
>> - * allocations.
>> +/* By default transparent hugepage support is disabled in order that avoid

Should be:
+/*
+ * By default transparent hugepage support is disabled in order that avoid

Please review the resend one.

Thanks.

>> + * to risk increase the memory footprint of applications without a guaranteed
>> + * benefit. When transparent hugepage support is enabled, is for all mappings,
>> + * and khugepaged scans all mappings.
>> + * Defrag is invoked by khugepaged hugepage allocations and by page faults
>> + * for all hugepage allocations.
>> */
>> unsigned long transparent_hugepage_flags __read_mostly =
>> #ifdef CONFIG_TRANSPARENT_HUGEPAGE_ALWAYS
>> --
>> 1.7.1
>>
>
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