Merge branch 'akpm'

* akpm: (182 commits)
  fbdev: bf54x-lq043fb: use kzalloc over kmalloc/memset
  fbdev: *bfin*: fix __dev{init,exit} markings
  fbdev: *bfin*: drop unnecessary calls to memset
  fbdev: bfin-t350mcqb-fb: drop unused local variables
  fbdev: blackfin has __raw I/O accessors, so use them in fb.h
  fbdev: s1d13xxxfb: add accelerated bitblt functions
  tcx: use standard fields for framebuffer physical address and length
  fbdev: add support for handoff from firmware to hw framebuffers
  intelfb: fix a bug when changing video timing
  fbdev: use framebuffer_release() for freeing fb_info structures
  radeon: P2G2CLK_ALWAYS_ONb tested twice, should 2nd be P2G2CLK_DAC_ALWAYS_ONb?
  s3c-fb: CPUFREQ frequency scaling support
  s3c-fb: fix resource releasing on error during probing
  carminefb: fix possible access beyond end of carmine_modedb[]
  acornfb: remove fb_mmap function
  mb862xxfb: use CONFIG_OF instead of CONFIG_PPC_OF
  mb862xxfb: restrict compliation of platform driver to PPC
  Samsung SoC Framebuffer driver: add Alpha Channel support
  atmel-lcdc: fix pixclock upper bound detection
  offb: use framebuffer_alloc() to allocate fb_info struct
  ...

Manually fix up conflicts due to kmemcheck in mm/slab.c

10 files changed, 806 insertions, 31 deletions

diff --git a/Documentation/accounting/getdelays.c b/Documentation/accounting/getdelays.c
index 7ea231172c85..aa73e72fd793 100644
--- a/Documentation/accounting/getdelays.c
+++ b/Documentation/accounting/getdelays.c
@@ -246,7 +246,8 @@ void print_ioacct(struct taskstats *t)
 
 int main(int argc, char *argv[])
 {
-        int c, rc, rep_len, aggr_len, len2, cmd_type;
+        int c, rc, rep_len, aggr_len, len2;
+        int cmd_type = TASKSTATS_CMD_ATTR_UNSPEC;
         __u16 id;
         __u32 mypid;
 
diff --git a/Documentation/atomic_ops.txt b/Documentation/atomic_ops.txt
index 4ef245010457..396bec3b74ed 100644
--- a/Documentation/atomic_ops.txt
+++ b/Documentation/atomic_ops.txt
@@ -229,10 +229,10 @@ kernel.  It is the use of atomic counters to implement reference
 counting, and it works such that once the counter falls to zero it can
 be guaranteed that no other entity can be accessing the object:
 
-static void obj_list_add(struct obj *obj)
+static void obj_list_add(struct obj *obj, struct list_head *head)
 {
         obj->active = 1;
-        list_add(&obj->list);
+        list_add(&obj->list, head);
 }
 
 static void obj_list_del(struct obj *obj)
diff --git a/Documentation/fb/vesafb.txt b/Documentation/fb/vesafb.txt
index ee277dd204b0..950d5a658cb3 100644
--- a/Documentation/fb/vesafb.txt
+++ b/Documentation/fb/vesafb.txt
@@ -95,7 +95,7 @@ There is no way to change the vesafb video mode and/or timings after
 booting linux.  If you are not happy with the 60 Hz refresh rate, you
 have these options:
 
- * configure and load the DOS-Tools for your the graphics board (if
+ * configure and load the DOS-Tools for the graphics board (if
    available) and boot linux with loadlin.
  * use a native driver (matroxfb/atyfb) instead if vesafb.  If none
    is available, write a new one!
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index cd8717a36271..ebff3c10a07f 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -1003,11 +1003,13 @@ CHAPTER 3: PER-PROCESS PARAMETERS
 3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score
 ------------------------------------------------------
 
-This file can be used to adjust the score used to select which processes
-should be killed in an  out-of-memory  situation.  Giving it a high score will
-increase the likelihood of this process being killed by the oom-killer.  Valid
-values are in the range -16 to +15, plus the special value -17, which disables
-oom-killing altogether for this process.
+This file can be used to adjust the score used to select which processes should
+be killed in an out-of-memory situation.  The oom_adj value is a characteristic
+of the task's mm, so all threads that share an mm with pid will have the same
+oom_adj value.  A high value will increase the likelihood of this process being
+killed by the oom-killer.  Valid values are in the range -16 to +15 as
+explained below and a special value of -17, which disables oom-killing
+altogether for threads sharing pid's mm.
 
 The process to be killed in an out-of-memory situation is selected among all others
 based on its badness score. This value equals the original memory size of the process
@@ -1021,6 +1023,9 @@ the parent's score if they do not share the same memory. Thus forking servers
 are the prime candidates to be killed. Having only one 'hungry' child will make
 parent less preferable than the child.
 
+/proc/<pid>/oom_adj cannot be changed for kthreads since they are immune from
+oom-killing already.
+
 /proc/<pid>/oom_score shows process' current badness score.
 
 The following heuristics are then applied:
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index ad3800630772..5578248c18a4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -546,6 +546,10 @@ and is between 256 and 4096 characters. It is defined in the file
                         console=brl,ttyS0
                 For now, only VisioBraille is supported.
 
+        consoleblank=   [KNL] The console blank (screen saver) timeout in
+                        seconds. Defaults to 10*60 = 10mins. A value of 0
+                        disables the blank timer.
+
         coredump_filter=
                         [KNL] Change the default value for
                         /proc/<pid>/coredump_filter.
diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt
index 6fab2dcbb4d3..c4de6359d440 100644
--- a/Documentation/sysctl/vm.txt
+++ b/Documentation/sysctl/vm.txt
@@ -233,8 +233,8 @@ These protections are added to score to judge whether this zone should be used
 for page allocation or should be reclaimed.
 
 In this example, if normal pages (index=2) are required to this DMA zone and
-pages_high is used for watermark, the kernel judges this zone should not be
-used because pages_free(1355) is smaller than watermark + protection[2]
+watermark[WMARK_HIGH] is used for watermark, the kernel judges this zone should
+not be used because pages_free(1355) is smaller than watermark + protection[2]
 (4 + 2004 = 2008). If this protection value is 0, this zone would be used for
 normal page requirement. If requirement is DMA zone(index=0), protection[0]
 (=0) is used.
@@ -280,9 +280,10 @@ The default value is 65536.
 min_free_kbytes:
 
 This is used to force the Linux VM to keep a minimum number
-of kilobytes free.  The VM uses this number to compute a pages_min
-value for each lowmem zone in the system.  Each lowmem zone gets
-a number of reserved free pages based proportionally on its size.
+of kilobytes free.  The VM uses this number to compute a
+watermark[WMARK_MIN] value for each lowmem zone in the system.
+Each lowmem zone gets a number of reserved free pages based
+proportionally on its size.
 
 Some minimal amount of memory is needed to satisfy PF_MEMALLOC
 allocations; if you set this to lower than 1024KB, your system will
@@ -314,10 +315,14 @@ min_unmapped_ratio:
 
 This is available only on NUMA kernels.
 
-A percentage of the total pages in each zone.  Zone reclaim will only
-occur if more than this percentage of pages are file backed and unmapped.
-This is to insure that a minimal amount of local pages is still available for
-file I/O even if the node is overallocated.
+This is a percentage of the total pages in each zone. Zone reclaim will
+only occur if more than this percentage of pages are in a state that
+zone_reclaim_mode allows to be reclaimed.
+
+If zone_reclaim_mode has the value 4 OR'd, then the percentage is compared
+against all file-backed unmapped pages including swapcache pages and tmpfs
+files. Otherwise, only unmapped pages backed by normal files but not tmpfs
+files and similar are considered.
 
 The default is 1 percent.
 
diff --git a/Documentation/vm/Makefile b/Documentation/vm/Makefile
index 6f562f778b28..27479d43a9b0 100644
--- a/Documentation/vm/Makefile
+++ b/Documentation/vm/Makefile
@@ -2,7 +2,7 @@
 obj- := dummy.o
 
 # List of programs to build
-hostprogs-y := slabinfo
+hostprogs-y := slabinfo slqbinfo page-types
 
 # Tell kbuild to always build the programs
 always := $(hostprogs-y)
diff --git a/Documentation/vm/balance b/Documentation/vm/balance
index bd3d31bc4915..c46e68cf9344 100644
--- a/Documentation/vm/balance
+++ b/Documentation/vm/balance
@@ -75,15 +75,15 @@ Page stealing from process memory and shm is done if stealing the page would
 alleviate memory pressure on any zone in the page's node that has fallen below
 its watermark.
 
-pages_min/pages_low/pages_high/low_on_memory/zone_wake_kswapd: These are 
-per-zone fields, used to determine when a zone needs to be balanced. When
-the number of pages falls below pages_min, the hysteric field low_on_memory
-gets set. This stays set till the number of free pages becomes pages_high.
-When low_on_memory is set, page allocation requests will try to free some
-pages in the zone (providing GFP_WAIT is set in the request). Orthogonal
-to this, is the decision to poke kswapd to free some zone pages. That
-decision is not hysteresis based, and is done when the number of free
-pages is below pages_low; in which case zone_wake_kswapd is also set.
+watemark[WMARK_MIN/WMARK_LOW/WMARK_HIGH]/low_on_memory/zone_wake_kswapd: These
+are per-zone fields, used to determine when a zone needs to be balanced. When
+the number of pages falls below watermark[WMARK_MIN], the hysteric field
+low_on_memory gets set. This stays set till the number of free pages becomes
+watermark[WMARK_HIGH]. When low_on_memory is set, page allocation requests will
+try to free some pages in the zone (providing GFP_WAIT is set in the request).
+Orthogonal to this, is the decision to poke kswapd to free some zone pages.
+That decision is not hysteresis based, and is done when the number of free
+pages is below watermark[WMARK_LOW]; in which case zone_wake_kswapd is also set.
 
 
 (Good) Ideas that I have heard:
diff --git a/Documentation/vm/page-types.c b/Documentation/vm/page-types.c
new file mode 100644
index 000000000000..0833f44ba16b
--- /dev/null
+++ b/Documentation/vm/page-types.c
@@ -0,0 +1,698 @@
+/*
+ * page-types: Tool for querying page flags
+ *
+ * Copyright (C) 2009 Intel corporation
+ * Copyright (C) 2009 Wu Fengguang <fengguang.wu@intel.com>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <string.h>
+#include <getopt.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/errno.h>
+#include <sys/fcntl.h>
+
+
+/*
+ * kernel page flags
+ */
+
+#define KPF_BYTES               8
+#define PROC_KPAGEFLAGS         "/proc/kpageflags"
+
+/* copied from kpageflags_read() */
+#define KPF_LOCKED              0
+#define KPF_ERROR               1
+#define KPF_REFERENCED          2
+#define KPF_UPTODATE            3
+#define KPF_DIRTY               4
+#define KPF_LRU                 5
+#define KPF_ACTIVE              6
+#define KPF_SLAB                7
+#define KPF_WRITEBACK           8
+#define KPF_RECLAIM             9
+#define KPF_BUDDY               10
+
+/* [11-20] new additions in 2.6.31 */
+#define KPF_MMAP                11
+#define KPF_ANON                12
+#define KPF_SWAPCACHE           13
+#define KPF_SWAPBACKED          14
+#define KPF_COMPOUND_HEAD       15
+#define KPF_COMPOUND_TAIL       16
+#define KPF_HUGE                17
+#define KPF_UNEVICTABLE         18
+#define KPF_NOPAGE              20
+
+/* [32-] kernel hacking assistances */
+#define KPF_RESERVED            32
+#define KPF_MLOCKED             33
+#define KPF_MAPPEDTODISK        34
+#define KPF_PRIVATE             35
+#define KPF_PRIVATE_2           36
+#define KPF_OWNER_PRIVATE       37
+#define KPF_ARCH                38
+#define KPF_UNCACHED            39
+
+/* [48-] take some arbitrary free slots for expanding overloaded flags
+ * not part of kernel API
+ */
+#define KPF_READAHEAD           48
+#define KPF_SLOB_FREE           49
+#define KPF_SLUB_FROZEN         50
+#define KPF_SLUB_DEBUG          51
+
+#define KPF_ALL_BITS            ((uint64_t)~0ULL)
+#define KPF_HACKERS_BITS        (0xffffULL << 32)
+#define KPF_OVERLOADED_BITS     (0xffffULL << 48)
+#define BIT(name)               (1ULL << KPF_##name)
+#define BITS_COMPOUND           (BIT(COMPOUND_HEAD) | BIT(COMPOUND_TAIL))
+
+static char *page_flag_names[] = {
+        [KPF_LOCKED]            = "L:locked",
+        [KPF_ERROR]             = "E:error",
+        [KPF_REFERENCED]        = "R:referenced",
+        [KPF_UPTODATE]          = "U:uptodate",
+        [KPF_DIRTY]             = "D:dirty",
+        [KPF_LRU]               = "l:lru",
+        [KPF_ACTIVE]            = "A:active",
+        [KPF_SLAB]              = "S:slab",
+        [KPF_WRITEBACK]         = "W:writeback",
+        [KPF_RECLAIM]           = "I:reclaim",
+        [KPF_BUDDY]             = "B:buddy",
+
+        [KPF_MMAP]              = "M:mmap",
+        [KPF_ANON]              = "a:anonymous",
+        [KPF_SWAPCACHE]         = "s:swapcache",
+        [KPF_SWAPBACKED]        = "b:swapbacked",
+        [KPF_COMPOUND_HEAD]     = "H:compound_head",
+        [KPF_COMPOUND_TAIL]     = "T:compound_tail",
+        [KPF_HUGE]              = "G:huge",
+        [KPF_UNEVICTABLE]       = "u:unevictable",
+        [KPF_NOPAGE]            = "n:nopage",
+
+        [KPF_RESERVED]          = "r:reserved",
+        [KPF_MLOCKED]           = "m:mlocked",
+        [KPF_MAPPEDTODISK]      = "d:mappedtodisk",
+        [KPF_PRIVATE]           = "P:private",
+        [KPF_PRIVATE_2]         = "p:private_2",
+        [KPF_OWNER_PRIVATE]     = "O:owner_private",
+        [KPF_ARCH]              = "h:arch",
+        [KPF_UNCACHED]          = "c:uncached",
+
+        [KPF_READAHEAD]         = "I:readahead",
+        [KPF_SLOB_FREE]         = "P:slob_free",
+        [KPF_SLUB_FROZEN]       = "A:slub_frozen",
+        [KPF_SLUB_DEBUG]        = "E:slub_debug",
+};
+
+
+/*
+ * data structures
+ */
+
+static int              opt_raw;        /* for kernel developers */
+static int              opt_list;       /* list pages (in ranges) */
+static int              opt_no_summary; /* don't show summary */
+static pid_t            opt_pid;        /* process to walk */
+
+#define MAX_ADDR_RANGES 1024
+static int              nr_addr_ranges;
+static unsigned long    opt_offset[MAX_ADDR_RANGES];
+static unsigned long    opt_size[MAX_ADDR_RANGES];
+
+#define MAX_BIT_FILTERS 64
+static int              nr_bit_filters;
+static uint64_t         opt_mask[MAX_BIT_FILTERS];
+static uint64_t         opt_bits[MAX_BIT_FILTERS];
+
+static int              page_size;
+
+#define PAGES_BATCH     (64 << 10)      /* 64k pages */
+static int              kpageflags_fd;
+static uint64_t         kpageflags_buf[KPF_BYTES * PAGES_BATCH];
+
+#define HASH_SHIFT      13
+#define HASH_SIZE       (1 << HASH_SHIFT)
+#define HASH_MASK       (HASH_SIZE - 1)
+#define HASH_KEY(flags) (flags & HASH_MASK)
+
+static unsigned long    total_pages;
+static unsigned long    nr_pages[HASH_SIZE];
+static uint64_t         page_flags[HASH_SIZE];
+
+
+/*
+ * helper functions
+ */
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#define min_t(type, x, y) ({                    \
+        type __min1 = (x);                      \
+        type __min2 = (y);                      \
+        __min1 < __min2 ? __min1 : __min2; })
+
+unsigned long pages2mb(unsigned long pages)
+{
+        return (pages * page_size) >> 20;
+}
+
+void fatal(const char *x, ...)
+{
+        va_list ap;
+
+        va_start(ap, x);
+        vfprintf(stderr, x, ap);
+        va_end(ap);
+        exit(EXIT_FAILURE);
+}
+
+
+/*
+ * page flag names
+ */
+
+char *page_flag_name(uint64_t flags)
+{
+        static char buf[65];
+        int present;
+        int i, j;
+
+        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
+                present = (flags >> i) & 1;
+                if (!page_flag_names[i]) {
+                        if (present)
+                                fatal("unkown flag bit %d\n", i);
+                        continue;
+                }
+                buf[j++] = present ? page_flag_names[i][0] : '_';
+        }
+
+        return buf;
+}
+
+char *page_flag_longname(uint64_t flags)
+{
+        static char buf[1024];
+        int i, n;
+
+        for (i = 0, n = 0; i < ARRAY_SIZE(page_flag_names); i++) {
+                if (!page_flag_names[i])
+                        continue;
+                if ((flags >> i) & 1)
+                        n += snprintf(buf + n, sizeof(buf) - n, "%s,",
+                                        page_flag_names[i] + 2);
+        }
+        if (n)
+                n--;
+        buf[n] = '\0';
+
+        return buf;
+}
+
+
+/*
+ * page list and summary
+ */
+
+void show_page_range(unsigned long offset, uint64_t flags)
+{
+        static uint64_t      flags0;
+        static unsigned long index;
+        static unsigned long count;
+
+        if (flags == flags0 && offset == index + count) {
+                count++;
+                return;
+        }
+
+        if (count)
+                printf("%lu\t%lu\t%s\n",
+                                index, count, page_flag_name(flags0));
+
+        flags0 = flags;
+        index  = offset;
+        count  = 1;
+}
+
+void show_page(unsigned long offset, uint64_t flags)
+{
+        printf("%lu\t%s\n", offset, page_flag_name(flags));
+}
+
+void show_summary(void)
+{
+        int i;
+
+        printf("             flags\tpage-count       MB"
+                "  symbolic-flags\t\t\tlong-symbolic-flags\n");
+
+        for (i = 0; i < ARRAY_SIZE(nr_pages); i++) {
+                if (nr_pages[i])
+                        printf("0x%016llx\t%10lu %8lu  %s\t%s\n",
+                                (unsigned long long)page_flags[i],
+                                nr_pages[i],
+                                pages2mb(nr_pages[i]),
+                                page_flag_name(page_flags[i]),
+                                page_flag_longname(page_flags[i]));
+        }
+
+        printf("             total\t%10lu %8lu\n",
+                        total_pages, pages2mb(total_pages));
+}
+
+
+/*
+ * page flag filters
+ */
+
+int bit_mask_ok(uint64_t flags)
+{
+        int i;
+
+        for (i = 0; i < nr_bit_filters; i++) {
+                if (opt_bits[i] == KPF_ALL_BITS) {
+                        if ((flags & opt_mask[i]) == 0)
+                                return 0;
+                } else {
+                        if ((flags & opt_mask[i]) != opt_bits[i])
+                                return 0;
+                }
+        }
+
+        return 1;
+}
+
+uint64_t expand_overloaded_flags(uint64_t flags)
+{
+        /* SLOB/SLUB overload several page flags */
+        if (flags & BIT(SLAB)) {
+                if (flags & BIT(PRIVATE))
+                        flags ^= BIT(PRIVATE) | BIT(SLOB_FREE);
+                if (flags & BIT(ACTIVE))
+                        flags ^= BIT(ACTIVE) | BIT(SLUB_FROZEN);
+                if (flags & BIT(ERROR))
+                        flags ^= BIT(ERROR) | BIT(SLUB_DEBUG);
+        }
+
+        /* PG_reclaim is overloaded as PG_readahead in the read path */
+        if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
+                flags ^= BIT(RECLAIM) | BIT(READAHEAD);
+
+        return flags;
+}
+
+uint64_t well_known_flags(uint64_t flags)
+{
+        /* hide flags intended only for kernel hacker */
+        flags &= ~KPF_HACKERS_BITS;
+
+        /* hide non-hugeTLB compound pages */
+        if ((flags & BITS_COMPOUND) && !(flags & BIT(HUGE)))
+                flags &= ~BITS_COMPOUND;
+
+        return flags;
+}
+
+
+/*
+ * page frame walker
+ */
+
+int hash_slot(uint64_t flags)
+{
+        int k = HASH_KEY(flags);
+        int i;
+
+        /* Explicitly reserve slot 0 for flags 0: the following logic
+         * cannot distinguish an unoccupied slot from slot (flags==0).
+         */
+        if (flags == 0)
+                return 0;
+
+        /* search through the remaining (HASH_SIZE-1) slots */
+        for (i = 1; i < ARRAY_SIZE(page_flags); i++, k++) {
+                if (!k || k >= ARRAY_SIZE(page_flags))
+                        k = 1;
+                if (page_flags[k] == 0) {
+                        page_flags[k] = flags;
+                        return k;
+                }
+                if (page_flags[k] == flags)
+                        return k;
+        }
+
+        fatal("hash table full: bump up HASH_SHIFT?\n");
+        exit(EXIT_FAILURE);
+}
+
+void add_page(unsigned long offset, uint64_t flags)
+{
+        flags = expand_overloaded_flags(flags);
+
+        if (!opt_raw)
+                flags = well_known_flags(flags);
+
+        if (!bit_mask_ok(flags))
+                return;
+
+        if (opt_list == 1)
+                show_page_range(offset, flags);
+        else if (opt_list == 2)
+                show_page(offset, flags);
+
+        nr_pages[hash_slot(flags)]++;
+        total_pages++;
+}
+
+void walk_pfn(unsigned long index, unsigned long count)
+{
+        unsigned long batch;
+        unsigned long n;
+        unsigned long i;
+
+        if (index > ULONG_MAX / KPF_BYTES)
+                fatal("index overflow: %lu\n", index);
+
+        lseek(kpageflags_fd, index * KPF_BYTES, SEEK_SET);
+
+        while (count) {
+                batch = min_t(unsigned long, count, PAGES_BATCH);
+                n = read(kpageflags_fd, kpageflags_buf, batch * KPF_BYTES);
+                if (n == 0)
+                        break;
+                if (n < 0) {
+                        perror(PROC_KPAGEFLAGS);
+                        exit(EXIT_FAILURE);
+                }
+
+                if (n % KPF_BYTES != 0)
+                        fatal("partial read: %lu bytes\n", n);
+                n = n / KPF_BYTES;
+
+                for (i = 0; i < n; i++)
+                        add_page(index + i, kpageflags_buf[i]);
+
+                index += batch;
+                count -= batch;
+        }
+}
+
+void walk_addr_ranges(void)
+{
+        int i;
+
+        kpageflags_fd = open(PROC_KPAGEFLAGS, O_RDONLY);
+        if (kpageflags_fd < 0) {
+                perror(PROC_KPAGEFLAGS);
+                exit(EXIT_FAILURE);
+        }
+
+        if (!nr_addr_ranges)
+                walk_pfn(0, ULONG_MAX);
+
+        for (i = 0; i < nr_addr_ranges; i++)
+                walk_pfn(opt_offset[i], opt_size[i]);
+
+        close(kpageflags_fd);
+}
+
+
+/*
+ * user interface
+ */
+
+const char *page_flag_type(uint64_t flag)
+{
+        if (flag & KPF_HACKERS_BITS)
+                return "(r)";
+        if (flag & KPF_OVERLOADED_BITS)
+                return "(o)";
+        return "   ";
+}
+
+void usage(void)
+{
+        int i, j;
+
+        printf(
+"page-types [options]\n"
+"            -r|--raw                  Raw mode, for kernel developers\n"
+"            -a|--addr    addr-spec    Walk a range of pages\n"
+"            -b|--bits    bits-spec    Walk pages with specified bits\n"
+#if 0 /* planned features */
+"            -p|--pid     pid          Walk process address space\n"
+"            -f|--file    filename     Walk file address space\n"
+#endif
+"            -l|--list                 Show page details in ranges\n"
+"            -L|--list-each            Show page details one by one\n"
+"            -N|--no-summary           Don't show summay info\n"
+"            -h|--help                 Show this usage message\n"
+"addr-spec:\n"
+"            N                         one page at offset N (unit: pages)\n"
+"            N+M                       pages range from N to N+M-1\n"
+"            N,M                       pages range from N to M-1\n"
+"            N,                        pages range from N to end\n"
+"            ,M                        pages range from 0 to M\n"
+"bits-spec:\n"
+"            bit1,bit2                 (flags & (bit1|bit2)) != 0\n"
+"            bit1,bit2=bit1            (flags & (bit1|bit2)) == bit1\n"
+"            bit1,~bit2                (flags & (bit1|bit2)) == bit1\n"
+"            =bit1,bit2                flags == (bit1|bit2)\n"
+"bit-names:\n"
+        );
+
+        for (i = 0, j = 0; i < ARRAY_SIZE(page_flag_names); i++) {
+                if (!page_flag_names[i])
+                        continue;
+                printf("%16s%s", page_flag_names[i] + 2,
+                                 page_flag_type(1ULL << i));
+                if (++j > 3) {
+                        j = 0;
+                        putchar('\n');
+                }
+        }
+        printf("\n                                   "
+                "(r) raw mode bits  (o) overloaded bits\n");
+}
+
+unsigned long long parse_number(const char *str)
+{
+        unsigned long long n;
+
+        n = strtoll(str, NULL, 0);
+
+        if (n == 0 && str[0] != '0')
+                fatal("invalid name or number: %s\n", str);
+
+        return n;
+}
+
+void parse_pid(const char *str)
+{
+        opt_pid = parse_number(str);
+}
+
+void parse_file(const char *name)
+{
+}
+
+void add_addr_range(unsigned long offset, unsigned long size)
+{
+        if (nr_addr_ranges >= MAX_ADDR_RANGES)
+                fatal("too much addr ranges\n");
+
+        opt_offset[nr_addr_ranges] = offset;
+        opt_size[nr_addr_ranges] = size;
+        nr_addr_ranges++;
+}
+
+void parse_addr_range(const char *optarg)
+{
+        unsigned long offset;
+        unsigned long size;
+        char *p;
+
+        p = strchr(optarg, ',');
+        if (!p)
+                p = strchr(optarg, '+');
+
+        if (p == optarg) {
+                offset = 0;
+                size   = parse_number(p + 1);
+        } else if (p) {
+                offset = parse_number(optarg);
+                if (p[1] == '\0')
+                        size = ULONG_MAX;
+                else {
+                        size = parse_number(p + 1);
+                        if (*p == ',') {
+                                if (size < offset)
+                                        fatal("invalid range: %lu,%lu\n",
+                                                        offset, size);
+                                size -= offset;
+                        }
+                }
+        } else {
+                offset = parse_number(optarg);
+                size   = 1;
+        }
+
+        add_addr_range(offset, size);
+}
+
+void add_bits_filter(uint64_t mask, uint64_t bits)
+{
+        if (nr_bit_filters >= MAX_BIT_FILTERS)
+                fatal("too much bit filters\n");
+
+        opt_mask[nr_bit_filters] = mask;
+        opt_bits[nr_bit_filters] = bits;
+        nr_bit_filters++;
+}
+
+uint64_t parse_flag_name(const char *str, int len)
+{
+        int i;
+
+        if (!*str || !len)
+                return 0;
+
+        if (len <= 8 && !strncmp(str, "compound", len))
+                return BITS_COMPOUND;
+
+        for (i = 0; i < ARRAY_SIZE(page_flag_names); i++) {
+                if (!page_flag_names[i])
+                        continue;
+                if (!strncmp(str, page_flag_names[i] + 2, len))
+                        return 1ULL << i;
+        }
+
+        return parse_number(str);
+}
+
+uint64_t parse_flag_names(const char *str, int all)
+{
+        const char *p    = str;
+        uint64_t   flags = 0;
+
+        while (1) {
+                if (*p == ',' || *p == '=' || *p == '\0') {
+                        if ((*str != '~') || (*str == '~' && all && *++str))
+                                flags |= parse_flag_name(str, p - str);
+                        if (*p != ',')
+                                break;
+                        str = p + 1;
+                }
+                p++;
+        }
+
+        return flags;
+}
+
+void parse_bits_mask(const char *optarg)
+{
+        uint64_t mask;
+        uint64_t bits;
+        const char *p;
+
+        p = strchr(optarg, '=');
+        if (p == optarg) {
+                mask = KPF_ALL_BITS;
+                bits = parse_flag_names(p + 1, 0);
+        } else if (p) {
+                mask = parse_flag_names(optarg, 0);
+                bits = parse_flag_names(p + 1, 0);
+        } else if (strchr(optarg, '~')) {
+                mask = parse_flag_names(optarg, 1);
+                bits = parse_flag_names(optarg, 0);
+        } else {
+                mask = parse_flag_names(optarg, 0);
+                bits = KPF_ALL_BITS;
+        }
+
+        add_bits_filter(mask, bits);
+}
+
+
+struct option opts[] = {
+        { "raw"       , 0, NULL, 'r' },
+        { "pid"       , 1, NULL, 'p' },
+        { "file"      , 1, NULL, 'f' },
+        { "addr"      , 1, NULL, 'a' },
+        { "bits"      , 1, NULL, 'b' },
+        { "list"      , 0, NULL, 'l' },
+        { "list-each" , 0, NULL, 'L' },
+        { "no-summary", 0, NULL, 'N' },
+        { "help"      , 0, NULL, 'h' },
+        { NULL        , 0, NULL, 0 }
+};
+
+int main(int argc, char *argv[])
+{
+        int c;
+
+        page_size = getpagesize();
+
+        while ((c = getopt_long(argc, argv,
+                                "rp:f:a:b:lLNh", opts, NULL)) != -1) {
+                switch (c) {
+                case 'r':
+                        opt_raw = 1;
+                        break;
+                case 'p':
+                        parse_pid(optarg);
+                        break;
+                case 'f':
+                        parse_file(optarg);
+                        break;
+                case 'a':
+                        parse_addr_range(optarg);
+                        break;
+                case 'b':
+                        parse_bits_mask(optarg);
+                        break;
+                case 'l':
+                        opt_list = 1;
+                        break;
+                case 'L':
+                        opt_list = 2;
+                        break;
+                case 'N':
+                        opt_no_summary = 1;
+                        break;
+                case 'h':
+                        usage();
+                        exit(0);
+                default:
+                        usage();
+                        exit(1);
+                }
+        }
+
+        if (opt_list == 1)
+                printf("offset\tcount\tflags\n");
+        if (opt_list == 2)
+                printf("offset\tflags\n");
+
+        walk_addr_ranges();
+
+        if (opt_list == 1)
+                show_page_range(0, 0);  /* drain the buffer */
+
+        if (opt_no_summary)
+                return 0;
+
+        if (opt_list)
+                printf("\n\n");
+
+        show_summary();
+
+        return 0;
+}
diff --git a/Documentation/vm/pagemap.txt b/Documentation/vm/pagemap.txt
index ce72c0fe6177..600a304a828c 100644
--- a/Documentation/vm/pagemap.txt
+++ b/Documentation/vm/pagemap.txt
@@ -12,9 +12,9 @@ There are three components to pagemap:
    value for each virtual page, containing the following data (from
    fs/proc/task_mmu.c, above pagemap_read):
 
-    * Bits 0-55  page frame number (PFN) if present
+    * Bits 0-54  page frame number (PFN) if present
     * Bits 0-4   swap type if swapped
-    * Bits 5-55  swap offset if swapped
+    * Bits 5-54  swap offset if swapped
     * Bits 55-60 page shift (page size = 1<<page shift)
     * Bit  61    reserved for future use
     * Bit  62    page swapped
@@ -36,7 +36,7 @@ There are three components to pagemap:
  * /proc/kpageflags.  This file contains a 64-bit set of flags for each
    page, indexed by PFN.
 
-   The flags are (from fs/proc/proc_misc, above kpageflags_read):
+   The flags are (from fs/proc/page.c, above kpageflags_read):
 
      0. LOCKED
      1. ERROR
@@ -49,6 +49,68 @@ There are three components to pagemap:
      8. WRITEBACK
      9. RECLAIM
     10. BUDDY
+    11. MMAP
+    12. ANON
+    13. SWAPCACHE
+    14. SWAPBACKED
+    15. COMPOUND_HEAD
+    16. COMPOUND_TAIL
+    16. HUGE
+    18. UNEVICTABLE
+    20. NOPAGE
+
+Short descriptions to the page flags:
+
+ 0. LOCKED
+    page is being locked for exclusive access, eg. by undergoing read/write IO
+
+ 7. SLAB
+    page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator
+    When compound page is used, SLUB/SLQB will only set this flag on the head
+    page; SLOB will not flag it at all.
+
+10. BUDDY
+    a free memory block managed by the buddy system allocator
+    The buddy system organizes free memory in blocks of various orders.
+    An order N block has 2^N physically contiguous pages, with the BUDDY flag
+    set for and _only_ for the first page.
+
+15. COMPOUND_HEAD
+16. COMPOUND_TAIL
+    A compound page with order N consists of 2^N physically contiguous pages.
+    A compound page with order 2 takes the form of "HTTT", where H donates its
+    head page and T donates its tail page(s).  The major consumers of compound
+    pages are hugeTLB pages (Documentation/vm/hugetlbpage.txt), the SLUB etc.
+    memory allocators and various device drivers. However in this interface,
+    only huge/giga pages are made visible to end users.
+17. HUGE
+    this is an integral part of a HugeTLB page
+
+20. NOPAGE
+    no page frame exists at the requested address
+
+    [IO related page flags]
+ 1. ERROR     IO error occurred
+ 3. UPTODATE  page has up-to-date data
+              ie. for file backed page: (in-memory data revision >= on-disk one)
+ 4. DIRTY     page has been written to, hence contains new data
+              ie. for file backed page: (in-memory data revision >  on-disk one)
+ 8. WRITEBACK page is being synced to disk
+
+    [LRU related page flags]
+ 5. LRU         page is in one of the LRU lists
+ 6. ACTIVE      page is in the active LRU list
+18. UNEVICTABLE page is in the unevictable (non-)LRU list
+                It is somehow pinned and not a candidate for LRU page reclaims,
+                eg. ramfs pages, shmctl(SHM_LOCK) and mlock() memory segments
+ 2. REFERENCED  page has been referenced since last LRU list enqueue/requeue
+ 9. RECLAIM     page will be reclaimed soon after its pageout IO completed
+11. MMAP        a memory mapped page
+12. ANON        a memory mapped page that is not part of a file
+13. SWAPCACHE   page is mapped to swap space, ie. has an associated swap entry
+14. SWAPBACKED  page is backed by swap/RAM
+
+The page-types tool in this directory can be used to query the above flags.
 
 Using pagemap to do something useful: