Thread (71 messages) 71 messages, 10 authors, 2017-02-03

Re: [PATCH v2 12/12] mm: memory_hotplug: memory hotremove supports thp migration

From: Naoya Horiguchi <hidden>
Date: 2016-11-08 01:42:19
Also in: lkml
Subsystem: memory hot(un)plug, memory management, memory management - thp (transparent huge page), the rest · Maintainers: David Hildenbrand, Oscar Salvador, Andrew Morton, Lorenzo Stoakes, Linus Torvalds

On Tue, Nov 08, 2016 at 08:30:10AM +0800, kbuild test robot wrote:
Hi Naoya,

[auto build test WARNING on mmotm/master]
[also build test WARNING on next-20161028]
[cannot apply to v4.9-rc4]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Naoya-Horiguchi/mm-x86-move-_PAGE_SWP_SOFT_DIRTY-from-bit-7-to-bit-6/20161108-080615
base:   git://git.cmpxchg.org/linux-mmotm.git master
config: x86_64-randconfig-x003-201645 (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):

   mm/memory_hotplug.c: In function 'try_offline_node':
   mm/memory_hotplug.c:2131:6: warning: unused variable 'i' [-Wunused-variable]
     int i;
         ^
   In file included from include/uapi/linux/stddef.h:1:0,
                    from include/linux/stddef.h:4,
                    from mm/memory_hotplug.c:7:
This seems unrelated to my patchset, but the fix is easy.
I'll post a separate patch later.
   mm/memory_hotplug.c: In function 'new_node_page':
   include/linux/compiler.h:518:38: error: call to '__compiletime_assert_1575' declared with attribute error: BUILD_BUG failed
     _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
                                         ^
   include/linux/compiler.h:160:16: note: in definition of macro '__trace_if'
      ______r = !!(cond);     \
                   ^~~~
quoted
quoted
mm/memory_hotplug.c:1575:2: note: in expansion of macro 'if'
     if (new_page && order == HPAGE_PMD_ORDER)
     ^~
   include/linux/compiler.h:506:2: note: in expansion of macro '__compiletime_assert'
     __compiletime_assert(condition, msg, prefix, suffix)
     ^~~~~~~~~~~~~~~~~~~~
   include/linux/compiler.h:518:2: note: in expansion of macro '_compiletime_assert'
     _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
     ^~~~~~~~~~~~~~~~~~~
   include/linux/bug.h:54:37: note: in expansion of macro 'compiletime_assert'
    #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
                                        ^~~~~~~~~~~~~~~~~~
   include/linux/bug.h:88:21: note: in expansion of macro 'BUILD_BUG_ON_MSG'
    #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
                        ^~~~~~~~~~~~~~~~
   include/linux/huge_mm.h:181:28: note: in expansion of macro 'BUILD_BUG'
    #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
                               ^~~~~~~~~
   include/linux/huge_mm.h:56:26: note: in expansion of macro 'HPAGE_PMD_SHIFT'
    #define HPAGE_PMD_ORDER (HPAGE_PMD_SHIFT-PAGE_SHIFT)
                             ^~~~~~~~~~~~~~~
   mm/memory_hotplug.c:1575:27: note: in expansion of macro 'HPAGE_PMD_ORDER'
     if (new_page && order == HPAGE_PMD_ORDER)
                              ^~~~~~~~~~~~~~~
HPAGE_PMD_ORDER is not available in non-thp code now, so let's add
a simple wrapper to access it in generic code.

diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index 3c252cdef587..b75a9a1bbf3e 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -148,6 +148,12 @@ static inline int hpage_nr_pages(struct page *page)
 		return HPAGE_PMD_NR;
 	return 1;
 }
+static inline int hpage_order(struct page *page)
+{
+	if (unlikely(PageTransHuge(page)))
+		return HPAGE_PMD_ORDER;
+	return 0;
+}
 
 extern int do_huge_pmd_numa_page(struct fault_env *fe, pmd_t orig_pmd);
 
@@ -183,6 +189,7 @@ static inline bool thp_migration_supported(void)
 #define HPAGE_PMD_SIZE ({ BUILD_BUG(); 0; })
 
 #define hpage_nr_pages(x) 1
+#define hpage_order(x) 0
 
 #define transparent_hugepage_enabled(__vma) 0
 
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index a9c3fe1b55ea..d612a75ceec4 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1555,7 +1555,7 @@ static struct page *new_node_page(struct page *page, unsigned long private,
 					next_node_in(nid, nmask));
 
 	if (thp_migration_supported() && PageTransHuge(page)) {
-		order = HPAGE_PMD_ORDER;
+		order = hpage_order(page);
 		gfp_mask |= GFP_TRANSHUGE;
 	}
 
@@ -1572,7 +1572,7 @@ static struct page *new_node_page(struct page *page, unsigned long private,
 		new_page = __alloc_pages(gfp_mask, order,
 					node_zonelist(nid, gfp_mask));
 
-	if (new_page && order == HPAGE_PMD_ORDER)
+	if (new_page && order == hpage_order(page))
 		prep_transhuge_page(new_page);
 
 	return new_page;
@@ -1606,7 +1606,7 @@ do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)
 			continue;
 		} else if (thp_migration_supported() && PageTransHuge(page))
 			pfn = page_to_pfn(compound_head(page))
-				+ HPAGE_PMD_NR - 1;
+				+ hpage_nr_pages(page) - 1;
 
 		if (!get_page_unless_zero(page))
 			continue;
These changes are applied in the next version.

Thanks,
Naoya Horiguchi
vim +/if +1575 mm/memory_hotplug.c

  1559			gfp_mask |= GFP_TRANSHUGE;
  1560		}
  1561	
  1562		node_clear(nid, nmask);
  1563	
  1564		if (PageHighMem(page)
  1565		    || (zone_idx(page_zone(page)) == ZONE_MOVABLE))
  1566			gfp_mask |= __GFP_HIGHMEM;
  1567	
  1568		if (!nodes_empty(nmask))
  1569			new_page = __alloc_pages_nodemask(gfp_mask, order,
  1570						node_zonelist(nid, gfp_mask), &nmask);
  1571		if (!new_page)
  1572			new_page = __alloc_pages(gfp_mask, order,
  1573						node_zonelist(nid, gfp_mask));
  1574	
quoted
1575		if (new_page && order == HPAGE_PMD_ORDER)
  1576			prep_transhuge_page(new_page);
  1577	
  1578		return new_page;
  1579	}
  1580	
  1581	#define NR_OFFLINE_AT_ONCE_PAGES	(256)
  1582	static int
  1583	do_migrate_range(unsigned long start_pfn, unsigned long end_pfn)

---
0-DAY kernel test infrastructure                Open Source Technology Center
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