diff mbox series

[1/2] mm: memory_hotplug: enumerate all supported section flags

Message ID 20220519124632.92091-2-songmuchun@bytedance.com (mailing list archive)
State New
Headers show
Series make hugetlb_optimize_vmemmap compatible with memmap_on_memory | expand

Commit Message

Muchun Song May 19, 2022, 12:46 p.m. UTC 
We are almost running out of free slots, only one bit is available in the
worst case (powerpc with 256k pages).  However, there are still some free
slots on other architectures (e.g. x86_64 has 10 bits available, arm64
has 8 bits available with worst case of 64K pages).  We have hard coded
those numbers in code, it is inconvenient to use those bits on other
architectures except powerpc.  So transfer those section flags to
enumeration to make it easy to add new section flags in the future. Also,
move SECTION_TAINT_ZONE_DEVICE into the scope of CONFIG_ZONE_DEVICE
to save a bit on non-zone-device case.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/kconfig.h |  1 +
 include/linux/mmzone.h  | 47 +++++++++++++++++++++++++++++++++++++++--------
 mm/memory_hotplug.c     |  6 ++++++
 3 files changed, 46 insertions(+), 8 deletions(-)

Comments

kernel test robot May 19, 2022, 3:51 p.m. UTC | #1 
Hi Muchun,

I love your patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]
[also build test ERROR on linux/master linus/master v5.18-rc7 next-20220519]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/intel-lab-lkp/linux/commits/Muchun-Song/make-hugetlb_optimize_vmemmap-compatible-with-memmap_on_memory/20220519-204849
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
config: x86_64-randconfig-a016 (https://download.01.org/0day-ci/archive/20220519/202205192323.hAhv52wX-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project e00cbbec06c08dc616a0d52a20f678b8fbd4e304)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/94ab57cfaebf53ff1c57cc6c8b3ecc48bef31c5e
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Muchun-Song/make-hugetlb_optimize_vmemmap-compatible-with-memmap_on_memory/20220519-204849
        git checkout 94ab57cfaebf53ff1c57cc6c8b3ecc48bef31c5e
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=x86_64 prepare

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   In file included from arch/x86/kernel/asm-offsets.c:9:
   In file included from include/linux/crypto.h:20:
   In file included from include/linux/slab.h:15:
   In file included from include/linux/gfp.h:6:
>> include/linux/mmzone.h:1506:44: error: use of undeclared identifier 'SECTION_TAINT_ZONE_DEVICE'
           unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
                                                     ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:97:11: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
                   return (set->sig[3] | set->sig[2] |
                           ^        ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:97:25: warning: array index 2 is past the end of the array (which contains 1 element) [-Warray-bounds]
                   return (set->sig[3] | set->sig[2] |
                                         ^        ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:98:4: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
                           set->sig[1] | set->sig[0]) == 0;
                           ^        ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:100:11: warning: array index 1 is past the end of the array (which contains 1 element) [-Warray-bounds]
                   return (set->sig[1] | set->sig[0]) == 0;
                           ^        ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:113:11: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
                   return  (set1->sig[3] == set2->sig[3]) &&
                            ^         ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:
   In file included from include/linux/sched/signal.h:6:
   include/linux/signal.h:113:27: warning: array index 3 is past the end of the array (which contains 1 element) [-Warray-bounds]
                   return  (set1->sig[3] == set2->sig[3]) &&
                                            ^         ~
   arch/x86/include/asm/signal.h:24:2: note: array 'sig' declared here
           unsigned long sig[_NSIG_WORDS];
           ^
   In file included from arch/x86/kernel/asm-offsets.c:13:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:17:
   In file included from include/linux/fs.h:33:
   In file included from include/linux/percpu-rwsem.h:7:
   In file included from include/linux/rcuwait.h:6:


vim +/SECTION_TAINT_ZONE_DEVICE +1506 include/linux/mmzone.h

2d070eab2e8270 Michal Hocko 2017-07-06  1503  
1f90a3477df3ff Dan Williams 2021-02-25  1504  static inline int online_device_section(struct mem_section *section)
1f90a3477df3ff Dan Williams 2021-02-25  1505  {
1f90a3477df3ff Dan Williams 2021-02-25 @1506  	unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE;
1f90a3477df3ff Dan Williams 2021-02-25  1507  
1f90a3477df3ff Dan Williams 2021-02-25  1508  	return section && ((section->section_mem_map & flags) == flags);
1f90a3477df3ff Dan Williams 2021-02-25  1509  }
1f90a3477df3ff Dan Williams 2021-02-25  1510
diff mbox series

Patch

diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h
index 20d1079e92b4..7044032b9f42 100644
--- a/include/linux/kconfig.h
+++ b/include/linux/kconfig.h
@@ -10,6 +10,7 @@ 
 #define __LITTLE_ENDIAN 1234
 #endif
 
+#define __ARG_PLACEHOLDER_ 0,
 #define __ARG_PLACEHOLDER_1 0,
 #define __take_second_arg(__ignored, val, ...) val
 
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 299259cfe462..e0b7618d7212 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -1422,16 +1422,47 @@  extern size_t mem_section_usage_size(void);
  *      (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
  *      worst combination is powerpc with 256k pages,
  *      which results in PFN_SECTION_SHIFT equal 6.
- * To sum it up, at least 6 bits are available.
+ * To sum it up, at least 6 bits are available on all architectures.
+ * However, we can exceed 6 bits on some other architectures except
+ * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
+ * with the worst case of 64K pages on arm64) if we make sure the
+ * exceeded bit is not applicable to powerpc.
  */
-#define SECTION_MARKED_PRESENT		(1UL<<0)
-#define SECTION_HAS_MEM_MAP		(1UL<<1)
-#define SECTION_IS_ONLINE		(1UL<<2)
-#define SECTION_IS_EARLY		(1UL<<3)
-#define SECTION_TAINT_ZONE_DEVICE	(1UL<<4)
-#define SECTION_MAP_LAST_BIT		(1UL<<5)
+#define ENUM_SECTION_FLAG(MAPPER)						\
+	MAPPER(MARKED_PRESENT)							\
+	MAPPER(HAS_MEM_MAP)							\
+	MAPPER(IS_ONLINE)							\
+	MAPPER(IS_EARLY)							\
+	MAPPER(TAINT_ZONE_DEVICE, CONFIG_ZONE_DEVICE)				\
+	MAPPER(MAP_LAST_BIT)
+
+#define __SECTION_SHIFT_FLAG_MAPPER_0(x)
+#define __SECTION_SHIFT_FLAG_MAPPER_1(x)	SECTION_##x##_SHIFT,
+#define __SECTION_SHIFT_FLAG_MAPPER(x, ...)	\
+	__PASTE(__SECTION_SHIFT_FLAG_MAPPER_, IS_ENABLED(__VA_ARGS__))(x)
+
+#define __SECTION_FLAG_MAPPER_0(x)
+#define __SECTION_FLAG_MAPPER_1(x)		SECTION_##x = BIT(SECTION_##x##_SHIFT),
+#define __SECTION_FLAG_MAPPER(x, ...)		\
+	__PASTE(__SECTION_FLAG_MAPPER_, IS_ENABLED(__VA_ARGS__))(x)
+
+enum {
+	/*
+	 * Generate a series of enumeration flags like SECTION_$name_SHIFT.
+	 * Each entry in ENUM_SECTION_FLAG() macro will be generated to one
+	 * enumeration iff the 2nd parameter of MAPPER() is defined or absent.
+	 * The $name comes from the 1st parameter of MAPPER() macro.
+	 */
+	ENUM_SECTION_FLAG(__SECTION_SHIFT_FLAG_MAPPER)
+	/*
+	 * Generate a series of enumeration flags like:
+	 *   SECTION_$name = BIT(SECTION_$name_SHIFT)
+	 */
+	ENUM_SECTION_FLAG(__SECTION_FLAG_MAPPER)
+};
+
 #define SECTION_MAP_MASK		(~(SECTION_MAP_LAST_BIT-1))
-#define SECTION_NID_SHIFT		6
+#define SECTION_NID_SHIFT		SECTION_MAP_LAST_BIT_SHIFT
 
 static inline struct page *__section_mem_map_addr(struct mem_section *section)
 {
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 1213d0c67a53..3b360eda933f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -672,12 +672,18 @@  static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon
 
 }
 
+#ifdef CONFIG_ZONE_DEVICE
 static void section_taint_zone_device(unsigned long pfn)
 {
 	struct mem_section *ms = __pfn_to_section(pfn);
 
 	ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE;
 }
+#else
+static inline void section_taint_zone_device(unsigned long pfn)
+{
+}
+#endif
 
 /*
  * Associate the pfn range with the given zone, initializing the memmaps