Make split_page_count check for empty levels.
In PAGEALLOC_DEBUG builds, we disable the 2M pages. Unfortunatly when we split up mappings during boot, split_page_count doesn't take this into account, and starts decrementing an empty direct_pages_count level.
This results in /proc/meminfo showing crazy things like
DirectMap2M: 18446744073709543424 kB
Signed-off-by Dave Jones <[email protected]>
arch/x86/mm/pageattr.c +3 -0
@@ -66,6 +66,9 @@ void update_page_count(int level, unsigned long pages)static void split_page_count (int level) { +if (direct_pages_count[level] ==0 ) +return ; + direct_pages_count[level]--; direct_pages_count[level -1 ] +=PTRS_PER_PTE ; }
tip-bot for Dave Jones
merge bot[tip:x86/urgent] x86/mm: Make split_page_count check for empty levels
x86/mm: Make split_page_count check for empty levels
Commit-ID: 3f1ac1cdc4fdf894e35c0e4fd103b54eec8a28c0 Gitweb: http://git.kernel.org/tip/3f1ac1cdc4fdf894e35c0e4fd103b54eec8a28c0 Author: Dave Jones <[email protected]> AuthorDate: Mon, 11 Jan 2016 12:04:28 -0500 Committer: Thomas Gleixner <[email protected]> CommitDate: Tue, 12 Jan 2016 11:04:53 +0100
x86/mm: Make split_page_count check for empty levels
In PAGEALLOC_DEBUG builds, we disable the 2M pages. Unfortunatly when we split up mappings during boot, split_page_count doesn't take this into account, and starts decrementing an empty direct_pages_count level.
This results in /proc/meminfo showing crazy things like
DirectMap2M: 18446744073709543424 kB
Signed-off-by Dave Jones <[email protected]>
Signed-off-by Thomas Gleixner <[email protected]>
--- arch/x86/mm/pageattr.c | 3 +++ 1 file changed, 3 insertions(+)
arch/x86/mm/pageattr.c +3 -0
@@ -66,6 +66,9 @@ void update_page_count(int level, unsigned long pages)static void split_page_count (int level) { +if (direct_pages_count[level] ==0 ) +return ; + direct_pages_count[level]--; direct_pages_count[level -1 ] +=PTRS_PER_PTE ; }