Subject: [failures] mm-add-a-field-to-store-names-for-private-anonymous-memory.patch removed from -mm tree
To: ccross@xxxxxxxxxxx,dave.hansen@xxxxxxxxx,ebiederm@xxxxxxxxxxxx,gorcunov@xxxxxxxxxx,hannes@xxxxxxxxxxx,holt@xxxxxxx,hughd@xxxxxxxxxx,jan.glauber@xxxxxxxxx,john.stultz@xxxxxxxxxx,keescook@xxxxxxxxxxxx,mgorman@xxxxxxx,mingo@xxxxxxxxxx,oleg@xxxxxxxxxx,penberg@xxxxxxxxxx,peterz@xxxxxxxxxxxxx,riel@xxxxxxxxxx,rientjes@xxxxxxxxxx,rob@xxxxxxxxxxx,sasha.levin@xxxxxxxxxx,serge.hallyn@xxxxxxxxxx,shli@xxxxxxxxxxxx,tangchen@xxxxxxxxxxxxxx,viro@xxxxxxxxxxxxxxxxxx,walken@xxxxxxxxxx,mm-commits@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 30 Oct 2013 13:50:47 -0700
The patch titled
Subject: mm: add a field to store names for private anonymous memory
has been removed from the -mm tree. Its filename was
mm-add-a-field-to-store-names-for-private-anonymous-memory.patch
This patch was dropped because it had testing failures
------------------------------------------------------
From: Colin Cross <ccross@xxxxxxxxxxx>
Subject: mm: add a field to store names for private anonymous memory
In many userspace applications, and especially in VM based applications
like Android uses heavily, there are multiple different allocators in use.
At a minimum there is libc malloc and the stack, and in many cases there
are libc malloc, the stack, direct syscalls to mmap anonymous memory, and
multiple VM heaps (one for small objects, one for big objects, etc.).
Each of these layers usually has its own tools to inspect its usage;
malloc by compiling a debug version, the VM through heap inspection tools,
and for direct syscalls there is usually no way to track them.
On Android we heavily use a set of tools that use an extended version of
the logic covered in Documentation/vm/pagemap.txt to walk all pages mapped
in userspace and slice their usage by process, shared (COW) vs. unique
mappings, backing, etc. This can account for real physical memory usage
even in cases like fork without exec (which Android uses heavily to share
as many private COW pages as possible between processes), Kernel SamePage
Merging, and clean zero pages. It produces a measurement of the pages
that only exist in that process (USS, for unique), and a measurement of
the physical memory usage of that process with the cost of shared pages
being evenly split between processes that share them (PSS).
If all anonymous memory is indistinguishable then figuring out the real
physical memory usage (PSS) of each heap requires either a pagemap walking
tool that can understand the heap debugging of every layer, or for every
layer's heap debugging tools to implement the pagemap walking logic, in
which case it is hard to get a consistent view of memory across the whole
system.
This patch adds a field to /proc/pid/maps and /proc/pid/smaps to show a
userspace-provided name for anonymous vmas. The names of named anonymous
vmas are shown in /proc/pid/maps and /proc/pid/smaps as [anon:<name>].
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.
The name is stored in a user pointer in the shared union in vm_area_struct
that points to a null terminated string inside the user process. vmas
that point to the same address and are otherwise mergeable will be merged,
but vmas that point to equivalent strings at different addresses will not
be merged.
The idea to store a userspace pointer to reduce the complexity within mm
(at the expense of the complexity of reading /proc/pid/mem) came from Dave
Hansen. This results in no runtime overhead in the mm subsystem other
than comparing the anon_name pointers when considering vma merging. The
pointer is stored in a union with fields that are only used on file-backed
mappings, so it does not increase memory usage.
Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>
Cc: Pekka Enberg <penberg@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Oleg Nesterov <oleg@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Jan Glauber <jan.glauber@xxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Rob Landley <rob@xxxxxxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "Serge E. Hallyn" <serge.hallyn@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Michel Lespinasse <walken@xxxxxxxxxx>
Cc: Tang Chen <tangchen@xxxxxxxxxxxxxx>
Cc: Robin Holt <holt@xxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxxxx>
Cc: Sasha Levin <sasha.levin@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
Documentation/filesystems/proc.txt | 2
fs/proc/task_mmu.c | 22 ++++++++++
include/linux/mm.h | 5 +-
include/linux/mm_types.h | 15 +++++++
include/uapi/linux/prctl.h | 3 +
kernel/sys.c | 24 +++++++++++
mm/madvise.c | 55 +++++++++++++++++++++++++--
mm/mempolicy.c | 2
mm/mlock.c | 3 -
mm/mmap.c | 44 ++++++++++++---------
mm/mprotect.c | 3 -
11 files changed, 152 insertions(+), 26 deletions(-)
diff -puN Documentation/filesystems/proc.txt~mm-add-a-field-to-store-names-for-private-anonymous-memory Documentation/filesystems/proc.txt
--- a/Documentation/filesystems/proc.txt~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/Documentation/filesystems/proc.txt
@@ -369,6 +369,8 @@ is not associated with a file:
[stack:1001] = the stack of the thread with tid 1001
[vdso] = the "virtual dynamic shared object",
the kernel system call handler
+ [anon:<name>] = an anonymous mapping that has been
+ named by userspace
or if empty, the mapping is anonymous.
diff -puN fs/proc/task_mmu.c~mm-add-a-field-to-store-names-for-private-anonymous-memory fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/fs/proc/task_mmu.c
@@ -91,6 +91,22 @@ static void pad_len_spaces(struct seq_fi
seq_printf(m, "%*c", len, ' ');
}
+static void seq_print_vma_name(struct seq_file *m, struct vm_area_struct *vma)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ char anon_name[NAME_MAX + 1];
+ unsigned long addr;
+ int n;
+
+ n = access_remote_vm(mm, (unsigned long)vma_anon_name(vma),
+ anon_name, NAME_MAX, 0);
+ if (n > 0) {
+ seq_puts(m, "[anon:");
+ seq_write(m, anon_name, strnlen(anon_name, n));
+ seq_putc(m, ']');
+ }
+}
+
#ifdef CONFIG_NUMA
/*
* These functions are for numa_maps but called in generic **maps seq_file
@@ -336,6 +352,12 @@ show_map_vma(struct seq_file *m, struct
pad_len_spaces(m, len);
seq_printf(m, "[stack:%d]", tid);
}
+ goto done;
+ }
+
+ if (vma_anon_name(vma)) {
+ pad_len_spaces(m, len);
+ seq_print_vma_name(m, vma);
}
}
diff -puN include/linux/mm.h~mm-add-a-field-to-store-names-for-private-anonymous-memory include/linux/mm.h
--- a/include/linux/mm.h~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/include/linux/mm.h
@@ -1497,7 +1497,7 @@ extern int vma_adjust(struct vm_area_str
extern struct vm_area_struct *vma_merge(struct mm_struct *,
struct vm_area_struct *prev, unsigned long addr, unsigned long end,
unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
- struct mempolicy *);
+ struct mempolicy *, const char __user *);
extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
extern int split_vma(struct mm_struct *,
struct vm_area_struct *, unsigned long addr, int new_below);
@@ -1841,5 +1841,8 @@ void __init setup_nr_node_ids(void);
static inline void setup_nr_node_ids(void) {}
#endif
+int madvise_set_anon_name(unsigned long start, unsigned long len_in,
+ unsigned long name_addr);
+
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
diff -puN include/linux/mm_types.h~mm-add-a-field-to-store-names-for-private-anonymous-memory include/linux/mm_types.h
--- a/include/linux/mm_types.h~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/include/linux/mm_types.h
@@ -255,6 +255,10 @@ struct vm_area_struct {
* For areas with an address space and backing store,
* linkage into the address_space->i_mmap interval tree, or
* linkage of vma in the address_space->i_mmap_nonlinear list.
+ *
+ * For private anonymous mappings, a pointer to a null terminated string
+ * in the user process containing the name given to the vma, or NULL
+ * if unnamed.
*/
union {
struct {
@@ -262,6 +266,7 @@ struct vm_area_struct {
unsigned long rb_subtree_last;
} linear;
struct list_head nonlinear;
+ const char __user *anon_name;
} shared;
/*
@@ -455,4 +460,14 @@ static inline cpumask_t *mm_cpumask(stru
return mm->cpu_vm_mask_var;
}
+
+/* Return the name for an anonymous mapping or NULL for a file-backed mapping */
+static inline const char __user *vma_anon_name(struct vm_area_struct *vma)
+{
+ if (vma->vm_file)
+ return NULL;
+
+ return vma->shared.anon_name;
+}
+
#endif /* _LINUX_MM_TYPES_H */
diff -puN include/uapi/linux/prctl.h~mm-add-a-field-to-store-names-for-private-anonymous-memory include/uapi/linux/prctl.h
--- a/include/uapi/linux/prctl.h~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/include/uapi/linux/prctl.h
@@ -149,4 +149,7 @@
#define PR_GET_TID_ADDRESS 40
+#define PR_SET_VMA 0x53564d41
+# define PR_SET_VMA_ANON_NAME 0
+
#endif /* _LINUX_PRCTL_H */
diff -puN kernel/sys.c~mm-add-a-field-to-store-names-for-private-anonymous-memory kernel/sys.c
--- a/kernel/sys.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/kernel/sys.c
@@ -1836,6 +1836,27 @@ static int prctl_get_tid_address(struct
}
#endif
+static int prctl_set_vma(unsigned long opt, unsigned long addr,
+ unsigned long len, unsigned long arg)
+{
+ struct mm_struct *mm = current->mm;
+ int error;
+
+ down_write(&mm->mmap_sem);
+
+ switch (opt) {
+ case PR_SET_VMA_ANON_NAME:
+ error = madvise_set_anon_name(addr, len, arg);
+ break;
+ default:
+ error = -EINVAL;
+ }
+
+ up_write(&mm->mmap_sem);
+
+ return error;
+}
+
SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
unsigned long, arg4, unsigned long, arg5)
{
@@ -1999,6 +2020,9 @@ SYSCALL_DEFINE5(prctl, int, option, unsi
if (arg2 || arg3 || arg4 || arg5)
return -EINVAL;
return current->no_new_privs ? 1 : 0;
+ case PR_SET_VMA:
+ error = prctl_set_vma(arg2, arg3, arg4, arg5);
+ break;
default:
error = -EINVAL;
break;
diff -puN mm/madvise.c~mm-add-a-field-to-store-names-for-private-anonymous-memory mm/madvise.c
--- a/mm/madvise.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/mm/madvise.c
@@ -44,20 +44,22 @@ static int madvise_need_mmap_write(int b
*/
static int madvise_update_vma(struct vm_area_struct *vma,
struct vm_area_struct **prev, unsigned long start,
- unsigned long end, unsigned long new_flags)
+ unsigned long end, unsigned long new_flags,
+ const char __user *new_anon_name)
{
struct mm_struct *mm = vma->vm_mm;
pgoff_t pgoff;
int error;
- if (new_flags == vma->vm_flags) {
+ if (new_flags == vma->vm_flags && new_anon_name == vma_anon_name(vma)) {
*prev = vma;
return 0;
}
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma,
- vma->vm_file, pgoff, vma_policy(vma));
+ vma->vm_file, pgoff, vma_policy(vma),
+ new_anon_name);
if (*prev) {
vma = *prev;
goto success;
@@ -82,10 +84,30 @@ success:
* vm_flags is protected by the mmap_sem held in write mode.
*/
vma->vm_flags = new_flags;
+ if (!vma->vm_file)
+ vma->shared.anon_name = new_anon_name;
return 0;
}
+static int madvise_vma_anon_name(struct vm_area_struct *vma,
+ struct vm_area_struct **prev,
+ unsigned long start, unsigned long end,
+ unsigned long name_addr)
+{
+ int error;
+
+ /* Only anonymous mappings can be named */
+ if (vma->vm_file)
+ return -EINVAL;
+
+ error = madvise_update_vma(vma, prev, start, end, vma->vm_flags,
+ (const char __user *)name_addr);
+ if (error == -ENOMEM)
+ error = -EAGAIN;
+ return error;
+}
+
#ifdef CONFIG_SWAP
static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
unsigned long end, struct mm_walk *walk)
@@ -352,7 +374,8 @@ static int madvise_vma_behavior(struct v
break;
}
- error = madvise_update_vma(vma, prev, start, end, new_flags);
+ error = madvise_update_vma(vma, prev, start, end, new_flags,
+ vma_anon_name(vma));
out:
if (error == -ENOMEM)
@@ -494,6 +517,30 @@ int madvise_walk_vmas(unsigned long star
return unmapped_error;
}
+int madvise_set_anon_name(unsigned long start, unsigned long len_in,
+ unsigned long name_addr)
+{
+ unsigned long end;
+ unsigned long len;
+
+ if (start & ~PAGE_MASK)
+ return -EINVAL;
+ len = (len_in + ~PAGE_MASK) & PAGE_MASK;
+
+ /* Check to see whether len was rounded up from small -ve to zero */
+ if (len_in && !len)
+ return -EINVAL;
+
+ end = start + len;
+ if (end < start)
+ return -EINVAL;
+
+ if (end == start)
+ return 0;
+
+ return madvise_walk_vmas(start, end, name_addr, madvise_vma_anon_name);
+}
+
/*
* The madvise(2) system call.
*
diff -puN mm/mempolicy.c~mm-add-a-field-to-store-names-for-private-anonymous-memory mm/mempolicy.c
--- a/mm/mempolicy.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/mm/mempolicy.c
@@ -766,7 +766,7 @@ static int mbind_range(struct mm_struct
((vmstart - vma->vm_start) >> PAGE_SHIFT);
prev = vma_merge(mm, prev, vmstart, vmend, vma->vm_flags,
vma->anon_vma, vma->vm_file, pgoff,
- new_pol);
+ new_pol, vma_anon_name(name));
if (prev) {
vma = prev;
next = vma->vm_next;
diff -puN mm/mlock.c~mm-add-a-field-to-store-names-for-private-anonymous-memory mm/mlock.c
--- a/mm/mlock.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/mm/mlock.c
@@ -521,7 +521,8 @@ static int mlock_fixup(struct vm_area_st
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma,
- vma->vm_file, pgoff, vma_policy(vma));
+ vma->vm_file, pgoff, vma_policy(vma),
+ vma_anon_name(vma));
if (*prev) {
vma = *prev;
goto success;
diff -puN mm/mmap.c~mm-add-a-field-to-store-names-for-private-anonymous-memory mm/mmap.c
--- a/mm/mmap.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/mm/mmap.c
@@ -893,7 +893,8 @@ again: remove_next = 1 + (end > next->
* per-vma resources, so we don't attempt to merge those.
*/
static inline int is_mergeable_vma(struct vm_area_struct *vma,
- struct file *file, unsigned long vm_flags)
+ struct file *file, unsigned long vm_flags,
+ const char __user *anon_name)
{
if (vma->vm_flags ^ vm_flags)
return 0;
@@ -901,6 +902,8 @@ static inline int is_mergeable_vma(struc
return 0;
if (vma->vm_ops && vma->vm_ops->close)
return 0;
+ if (vma_anon_name(vma) != anon_name)
+ return 0;
return 1;
}
@@ -931,9 +934,10 @@ static inline int is_mergeable_anon_vma(
*/
static int
can_vma_merge_before(struct vm_area_struct *vma, unsigned long vm_flags,
- struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+ struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff,
+ const char __user *anon_name)
{
- if (is_mergeable_vma(vma, file, vm_flags) &&
+ if (is_mergeable_vma(vma, file, vm_flags, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
if (vma->vm_pgoff == vm_pgoff)
return 1;
@@ -950,9 +954,10 @@ can_vma_merge_before(struct vm_area_stru
*/
static int
can_vma_merge_after(struct vm_area_struct *vma, unsigned long vm_flags,
- struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff)
+ struct anon_vma *anon_vma, struct file *file, pgoff_t vm_pgoff,
+ const char __user *anon_name)
{
- if (is_mergeable_vma(vma, file, vm_flags) &&
+ if (is_mergeable_vma(vma, file, vm_flags, anon_name) &&
is_mergeable_anon_vma(anon_vma, vma->anon_vma, vma)) {
pgoff_t vm_pglen;
vm_pglen = vma_pages(vma);
@@ -963,9 +968,9 @@ can_vma_merge_after(struct vm_area_struc
}
/*
- * Given a mapping request (addr,end,vm_flags,file,pgoff), figure out
- * whether that can be merged with its predecessor or its successor.
- * Or both (it neatly fills a hole).
+ * Given a mapping request (addr,end,vm_flags,file,pgoff,anon_name),
+ * figure out whether that can be merged with its predecessor or its
+ * successor. Or both (it neatly fills a hole).
*
* In most cases - when called for mmap, brk or mremap - [addr,end) is
* certain not to be mapped by the time vma_merge is called; but when
@@ -995,7 +1000,8 @@ struct vm_area_struct *vma_merge(struct
struct vm_area_struct *prev, unsigned long addr,
unsigned long end, unsigned long vm_flags,
struct anon_vma *anon_vma, struct file *file,
- pgoff_t pgoff, struct mempolicy *policy)
+ pgoff_t pgoff, struct mempolicy *policy,
+ const char __user *anon_name)
{
pgoff_t pglen = (end - addr) >> PAGE_SHIFT;
struct vm_area_struct *area, *next;
@@ -1021,15 +1027,15 @@ struct vm_area_struct *vma_merge(struct
*/
if (prev && prev->vm_end == addr &&
mpol_equal(vma_policy(prev), policy) &&
- can_vma_merge_after(prev, vm_flags,
- anon_vma, file, pgoff)) {
+ can_vma_merge_after(prev, vm_flags, anon_vma,
+ file, pgoff, anon_name)) {
/*
* OK, it can. Can we now merge in the successor as well?
*/
if (next && end == next->vm_start &&
mpol_equal(policy, vma_policy(next)) &&
- can_vma_merge_before(next, vm_flags,
- anon_vma, file, pgoff+pglen) &&
+ can_vma_merge_before(next, vm_flags, anon_vma,
+ file, pgoff+pglen, anon_name) &&
is_mergeable_anon_vma(prev->anon_vma,
next->anon_vma, NULL)) {
/* cases 1, 6 */
@@ -1049,8 +1055,8 @@ struct vm_area_struct *vma_merge(struct
*/
if (next && end == next->vm_start &&
mpol_equal(policy, vma_policy(next)) &&
- can_vma_merge_before(next, vm_flags,
- anon_vma, file, pgoff+pglen)) {
+ can_vma_merge_before(next, vm_flags, anon_vma,
+ file, pgoff+pglen, anon_name)) {
if (prev && addr < prev->vm_end) /* case 4 */
err = vma_adjust(prev, prev->vm_start,
addr, prev->vm_pgoff, NULL);
@@ -1522,7 +1528,8 @@ munmap_back:
/*
* Can we just expand an old mapping?
*/
- vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff, NULL);
+ vma = vma_merge(mm, prev, addr, addr + len, vm_flags, NULL, file, pgoff,
+ NULL, NULL);
if (vma)
goto out;
@@ -2634,7 +2641,7 @@ static unsigned long do_brk(unsigned lon
/* Can we just expand an old private anonymous mapping? */
vma = vma_merge(mm, prev, addr, addr + len, flags,
- NULL, NULL, pgoff, NULL);
+ NULL, NULL, pgoff, NULL, NULL);
if (vma)
goto out;
@@ -2792,7 +2799,8 @@ struct vm_area_struct *copy_vma(struct v
if (find_vma_links(mm, addr, addr + len, &prev, &rb_link, &rb_parent))
return NULL; /* should never get here */
new_vma = vma_merge(mm, prev, addr, addr + len, vma->vm_flags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
+ vma_anon_name(vma));
if (new_vma) {
/*
* Source vma may have been merged into new_vma
diff -puN mm/mprotect.c~mm-add-a-field-to-store-names-for-private-anonymous-memory mm/mprotect.c
--- a/mm/mprotect.c~mm-add-a-field-to-store-names-for-private-anonymous-memory
+++ a/mm/mprotect.c
@@ -274,7 +274,8 @@ mprotect_fixup(struct vm_area_struct *vm
*/
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*pprev = vma_merge(mm, *pprev, start, end, newflags,
- vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma));
+ vma->anon_vma, vma->vm_file, pgoff, vma_policy(vma),
+ vma_anon_name(vma));
if (*pprev) {
vma = *pprev;
goto success;
_
Patches currently in -mm which might be from ccross@xxxxxxxxxxx are
mm-add-a-field-to-store-names-for-private-anonymous-memory-fix.patch
mm-add-a-field-to-store-names-for-private-anonymous-memory-fix-fix-2.patch
linux-next.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
