* [PATCH] rmap: Fix compound check logic in page_remove_file_rmap
@ 2016-08-09 12:34 ` Steve Capper
0 siblings, 0 replies; 4+ messages in thread
From: Steve Capper @ 2016-08-09 12:34 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel, shijie.huang, will.deacon, catalin.marinas
In page_remove_file_rmap(.) we have the following check:
VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
This is meant to check for either HugeTLB pages or THP when a compound
page is passed in.
Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
PageTransHuge(.) will always return false provoking BUGs when one runs
the libhugetlbfs test suite.
Changing the definition of PageTransHuge to be defined for
!CONFIG_TRANSPARENT_HUGEPAGE turned out to provoke build bugs; so this
patch instead replaces the errant check with:
PageTransHuge(page) || PageHuge(page)
Fixes: dd78fedde4b9 ("rmap: support file thp")
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
---
mm/rmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 709bc83..ad8fc51 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1303,7 +1303,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
{
int i, nr = 1;
- VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
+ VM_BUG_ON_PAGE(compound && !(PageTransHuge(page) || PageHuge(page)), page);
lock_page_memcg(page);
/* Hugepages are not counted in NR_FILE_MAPPED for now. */
--
1.8.3.1
--
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^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH] rmap: Fix compound check logic in page_remove_file_rmap
@ 2016-08-09 12:34 ` Steve Capper
0 siblings, 0 replies; 4+ messages in thread
From: Steve Capper @ 2016-08-09 12:34 UTC (permalink / raw)
To: linux-mm; +Cc: linux-kernel, shijie.huang, will.deacon, catalin.marinas
In page_remove_file_rmap(.) we have the following check:
VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
This is meant to check for either HugeTLB pages or THP when a compound
page is passed in.
Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
PageTransHuge(.) will always return false provoking BUGs when one runs
the libhugetlbfs test suite.
Changing the definition of PageTransHuge to be defined for
!CONFIG_TRANSPARENT_HUGEPAGE turned out to provoke build bugs; so this
patch instead replaces the errant check with:
PageTransHuge(page) || PageHuge(page)
Fixes: dd78fedde4b9 ("rmap: support file thp")
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steve Capper <steve.capper@arm.com>
---
mm/rmap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/rmap.c b/mm/rmap.c
index 709bc83..ad8fc51 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1303,7 +1303,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
{
int i, nr = 1;
- VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
+ VM_BUG_ON_PAGE(compound && !(PageTransHuge(page) || PageHuge(page)), page);
lock_page_memcg(page);
/* Hugepages are not counted in NR_FILE_MAPPED for now. */
--
1.8.3.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] rmap: Fix compound check logic in page_remove_file_rmap
2016-08-09 12:34 ` Steve Capper
@ 2016-08-09 16:29 ` Kirill A. Shutemov
-1 siblings, 0 replies; 4+ messages in thread
From: Kirill A. Shutemov @ 2016-08-09 16:29 UTC (permalink / raw)
To: Steve Capper
Cc: linux-mm, linux-kernel, shijie.huang, will.deacon,
catalin.marinas
On Tue, Aug 09, 2016 at 01:34:35PM +0100, Steve Capper wrote:
> In page_remove_file_rmap(.) we have the following check:
> VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
>
> This is meant to check for either HugeTLB pages or THP when a compound
> page is passed in.
>
> Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
> PageTransHuge(.) will always return false provoking BUGs when one runs
> the libhugetlbfs test suite.
>
> Changing the definition of PageTransHuge to be defined for
> !CONFIG_TRANSPARENT_HUGEPAGE turned out to provoke build bugs; so this
> patch instead replaces the errant check with:
> PageTransHuge(page) || PageHuge(page)
I think PageHead() check should be enough to cover this.
>
> Fixes: dd78fedde4b9 ("rmap: support file thp")
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Steve Capper <steve.capper@arm.com>
> ---
> mm/rmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 709bc83..ad8fc51 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1303,7 +1303,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
> {
> int i, nr = 1;
>
> - VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
> + VM_BUG_ON_PAGE(compound && !(PageTransHuge(page) || PageHuge(page)), page);
> lock_page_memcg(page);
>
> /* Hugepages are not counted in NR_FILE_MAPPED for now. */
> --
> 1.8.3.1
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
--
Kirill A. Shutemov
--
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^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH] rmap: Fix compound check logic in page_remove_file_rmap
@ 2016-08-09 16:29 ` Kirill A. Shutemov
0 siblings, 0 replies; 4+ messages in thread
From: Kirill A. Shutemov @ 2016-08-09 16:29 UTC (permalink / raw)
To: Steve Capper
Cc: linux-mm, linux-kernel, shijie.huang, will.deacon,
catalin.marinas
On Tue, Aug 09, 2016 at 01:34:35PM +0100, Steve Capper wrote:
> In page_remove_file_rmap(.) we have the following check:
> VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
>
> This is meant to check for either HugeTLB pages or THP when a compound
> page is passed in.
>
> Unfortunately, if one disables CONFIG_TRANSPARENT_HUGEPAGE, then
> PageTransHuge(.) will always return false provoking BUGs when one runs
> the libhugetlbfs test suite.
>
> Changing the definition of PageTransHuge to be defined for
> !CONFIG_TRANSPARENT_HUGEPAGE turned out to provoke build bugs; so this
> patch instead replaces the errant check with:
> PageTransHuge(page) || PageHuge(page)
I think PageHead() check should be enough to cover this.
>
> Fixes: dd78fedde4b9 ("rmap: support file thp")
> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: Steve Capper <steve.capper@arm.com>
> ---
> mm/rmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> index 709bc83..ad8fc51 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -1303,7 +1303,7 @@ static void page_remove_file_rmap(struct page *page, bool compound)
> {
> int i, nr = 1;
>
> - VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page);
> + VM_BUG_ON_PAGE(compound && !(PageTransHuge(page) || PageHuge(page)), page);
> lock_page_memcg(page);
>
> /* Hugepages are not counted in NR_FILE_MAPPED for now. */
> --
> 1.8.3.1
>
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@kvack.org. For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
--
Kirill A. Shutemov
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-08-09 16:29 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2016-08-09 12:34 [PATCH] rmap: Fix compound check logic in page_remove_file_rmap Steve Capper
2016-08-09 12:34 ` Steve Capper
2016-08-09 16:29 ` Kirill A. Shutemov
2016-08-09 16:29 ` Kirill A. Shutemov
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