xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mm: pack compound_dtor and compound_order into one word in struct page

Browse Source 
The patch halves space occupied by compound_dtor and compound_order in
struct page.

For compound_order, it's trivial long -> short conversion.

For get_compound_page_dtor(), we now use hardcoded table for destructor
lookup and store its index in the struct page instead of direct pointer
to destructor. It shouldn't be a big trouble to maintain the table: we
have only two destructor and NULL currently.

This patch free up one word in tail pages for reuse. This is preparation
for the next patch.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov
2015-11-06 16:29:50 -08:00
committed by Linus Torvalds
parent 32e7ba1ea1
commit f1e61557f0
4 changed files with 35 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
mm/page_alloc.c
View File

@@ -229,6 +229,15 @@ static char * const zone_names[MAX_NR_ZONES] = {
#endif
};
static void free_compound_page(struct page *page);
compound_page_dtor * const compound_page_dtors[] = {
NULL,
free_compound_page,
#ifdef CONFIG_HUGETLB_PAGE
free_huge_page,
#endif
};
int min_free_kbytes = 1024;
int user_min_free_kbytes = -1;
@@ -458,7 +467,7 @@ void prep_compound_page(struct page *page, unsigned long order)
int i;
int nr_pages = 1 << order;
set_compound_page_dtor(page, free_compound_page);
set_compound_page_dtor(page, COMPOUND_PAGE_DTOR);
set_compound_order(page, order);
__SetPageHead(page);
for (i = 1; i < nr_pages; i++) {