Thread (9 messages) 9 messages, 5 authors, 2011-03-19

Re: [PATCH] ksm: add vm_stat and meminfo entry to reflect pte mapping to ksm pages

From: Nai Xia <hidden>
Date: 2011-03-18 07:30:05
Also in: linux-mm, lkml

On Thursday 03 March 2011, at 06:31:42, <Andrew Morton [off-list ref]> wrote
This patch obviously wasn't tested with CONFIG_KSM=n, which was a
pretty basic patch-testing failure :(
Oops, I will be careful to avoid similar mistakes next time.
I fixed up my tree with the below, but really the amount of ifdeffing
is unacceptable - please find a cleaner way to fix up this patch.
Ok, I will have a try in my next patch submit. 

Thanks,
-Nai
quoted hunk ↗ jump to hunk
--- a/mm/ksm.c~ksm-add-vm_stat-and-meminfo-entry-to-reflect-pte-mapping-to-ksm-pages-fix
+++ a/mm/ksm.c
@@ -883,7 +883,6 @@ static int try_to_merge_one_page(struct 
 	 */
 	if (write_protect_page(vma, page, &orig_pte) = 0) {
 		if (!kpage) {
-			long mapcount = page_mapcount(page);
 			/*
 			 * While we hold page lock, upgrade page from
 			 * PageAnon+anon_vma to PageKsm+NULL stable_node:
@@ -891,10 +890,12 @@ static int try_to_merge_one_page(struct 
 			 */
 			set_page_stable_node(page, NULL);
 			mark_page_accessed(page);
-			if (mapcount)
+#ifdef CONFIG_KSM
+			if (page_mapcount(page))
 				add_zone_page_state(page_zone(page),
 						    NR_KSM_PAGES_SHARING,
 						    mapcount);
+#endif
 			err = 0;
 		} else if (pages_identical(page, kpage))
 			err = replace_page(vma, page, kpage, orig_pte);
--- a/mm/memory.c~ksm-add-vm_stat-and-meminfo-entry-to-reflect-pte-mapping-to-ksm-pages-fix
+++ a/mm/memory.c
@@ -719,8 +719,10 @@ copy_one_pte(struct mm_struct *dst_mm, s
 			rss[MM_ANONPAGES]++;
 		else
 			rss[MM_FILEPAGES]++;
+#ifdef CONFIG_KSM
 		if (PageKsm(page)) /* follows page_dup_rmap() */
 			inc_zone_page_state(page, NR_KSM_PAGES_SHARING);
+#endif
 	}
 
 out_set_pte:
--- a/mm/rmap.c~ksm-add-vm_stat-and-meminfo-entry-to-reflect-pte-mapping-to-ksm-pages-fix
+++ a/mm/rmap.c
@@ -893,11 +893,12 @@ void do_page_add_anon_rmap(struct page *
 			__inc_zone_page_state(page,
 					      NR_ANON_TRANSPARENT_HUGEPAGES);
 	}
+#ifdef CONFIG_KSM
 	if (unlikely(PageKsm(page))) {
 		__inc_zone_page_state(page, NR_KSM_PAGES_SHARING);
 		return;
 	}
-
+#endif
 	VM_BUG_ON(!PageLocked(page));
 	VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
 	if (first)
@@ -955,9 +956,10 @@ void page_add_file_rmap(struct page *pag
  */
 void page_remove_rmap(struct page *page)
 {
+#ifdef CONFIG_KSM
 	if (PageKsm(page))
 		__dec_zone_page_state(page, NR_KSM_PAGES_SHARING);
-
+#endif
 	/* page still mapped by someone else? */
 	if (!atomic_add_negative(-1, &page->_mapcount))
 		return;
_
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