This flag shows that soft dirty bit is not enabled yet.
You can enable it by "echo 4 > /proc/pid/clear_refs."
Signed-off-by: Naoya Horiguchi <[email protected]>
---
fs/proc/task_mmu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git v3.12-rc2-mmots-2013-09-24-17-03.orig/fs/proc/task_mmu.c v3.12-rc2-mmots-2013-09-24-17-03/fs/proc/task_mmu.c
index 7366e9d..c591928 100644
--- v3.12-rc2-mmots-2013-09-24-17-03.orig/fs/proc/task_mmu.c
+++ v3.12-rc2-mmots-2013-09-24-17-03/fs/proc/task_mmu.c
@@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_NONLINEAR)] = "nl",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_DONTDUMP)] = "dd",
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ [ilog2(VM_SOFTDIRTY)] = "sd",
+#endif
[ilog2(VM_MIXEDMAP)] = "mm",
[ilog2(VM_HUGEPAGE)] = "hg",
[ilog2(VM_NOHUGEPAGE)] = "nh",
--
1.8.3.1
Soft dirty bit allows us to track which pages are written since the
last clear_ref (by "echo 4 > /proc/pid/clear_refs".) This is useful
for userspace applications to know their memory footprints.
Note that the kernel exposes this flag via bit[55] of /proc/pid/pagemap,
and the semantics is not a default one (scheduled to be the default in
the near future.) However, it shifts to the new semantics at the first
clear_ref, and the users of soft dirty bit always do it before utilizing
the bit, so that's not a big deal. Users must avoid relying on the bit
in page-types before the first clear_ref.
Signed-off-by: Naoya Horiguchi <[email protected]>
---
include/linux/kernel-page-flags.h | 1 +
tools/vm/page-types.c | 32 ++++++++++++++++++++------------
2 files changed, 21 insertions(+), 12 deletions(-)
diff --git v3.12-rc2-mmots-2013-09-24-17-03.orig/include/linux/kernel-page-flags.h v3.12-rc2-mmots-2013-09-24-17-03/include/linux/kernel-page-flags.h
index 546eb6a..f65ce09 100644
--- v3.12-rc2-mmots-2013-09-24-17-03.orig/include/linux/kernel-page-flags.h
+++ v3.12-rc2-mmots-2013-09-24-17-03/include/linux/kernel-page-flags.h
@@ -15,5 +15,6 @@
#define KPF_OWNER_PRIVATE 37
#define KPF_ARCH 38
#define KPF_UNCACHED 39
+#define KPF_SOFTDIRTY 40
#endif /* LINUX_KERNEL_PAGE_FLAGS_H */
diff --git v3.12-rc2-mmots-2013-09-24-17-03.orig/tools/vm/page-types.c v3.12-rc2-mmots-2013-09-24-17-03/tools/vm/page-types.c
index 71c9c25..d5e9d6d 100644
--- v3.12-rc2-mmots-2013-09-24-17-03.orig/tools/vm/page-types.c
+++ v3.12-rc2-mmots-2013-09-24-17-03/tools/vm/page-types.c
@@ -59,12 +59,14 @@
#define PM_PSHIFT_BITS 6
#define PM_PSHIFT_OFFSET (PM_STATUS_OFFSET - PM_PSHIFT_BITS)
#define PM_PSHIFT_MASK (((1LL << PM_PSHIFT_BITS) - 1) << PM_PSHIFT_OFFSET)
-#define PM_PSHIFT(x) (((u64) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
+#define __PM_PSHIFT(x) (((uint64_t) (x) << PM_PSHIFT_OFFSET) & PM_PSHIFT_MASK)
#define PM_PFRAME_MASK ((1LL << PM_PSHIFT_OFFSET) - 1)
#define PM_PFRAME(x) ((x) & PM_PFRAME_MASK)
+#define __PM_SOFT_DIRTY (1LL)
#define PM_PRESENT PM_STATUS(4LL)
#define PM_SWAP PM_STATUS(2LL)
+#define PM_SOFT_DIRTY __PM_PSHIFT(__PM_SOFT_DIRTY)
/*
@@ -83,6 +85,7 @@
#define KPF_OWNER_PRIVATE 37
#define KPF_ARCH 38
#define KPF_UNCACHED 39
+#define KPF_SOFTDIRTY 40
/* [48-] take some arbitrary free slots for expanding overloaded flags
* not part of kernel API
@@ -132,6 +135,7 @@ static const char * const page_flag_names[] = {
[KPF_OWNER_PRIVATE] = "O:owner_private",
[KPF_ARCH] = "h:arch",
[KPF_UNCACHED] = "c:uncached",
+ [KPF_SOFTDIRTY] = "f:softdirty",
[KPF_READAHEAD] = "I:readahead",
[KPF_SLOB_FREE] = "P:slob_free",
@@ -417,7 +421,7 @@ static int bit_mask_ok(uint64_t flags)
return 1;
}
-static uint64_t expand_overloaded_flags(uint64_t flags)
+static uint64_t expand_overloaded_flags(uint64_t flags, uint64_t pme)
{
/* SLOB/SLUB overload several page flags */
if (flags & BIT(SLAB)) {
@@ -433,6 +437,9 @@ static uint64_t expand_overloaded_flags(uint64_t flags)
if ((flags & (BIT(RECLAIM) | BIT(WRITEBACK))) == BIT(RECLAIM))
flags ^= BIT(RECLAIM) | BIT(READAHEAD);
+ if (pme & PM_SOFT_DIRTY)
+ flags |= BIT(SOFTDIRTY);
+
return flags;
}
@@ -448,11 +455,11 @@ static uint64_t well_known_flags(uint64_t flags)
return flags;
}
-static uint64_t kpageflags_flags(uint64_t flags)
+static uint64_t kpageflags_flags(uint64_t flags, uint64_t pme)
{
- flags = expand_overloaded_flags(flags);
-
- if (!opt_raw)
+ if (opt_raw)
+ flags = expand_overloaded_flags(flags, pme);
+ else
flags = well_known_flags(flags);
return flags;
@@ -545,9 +552,9 @@ static size_t hash_slot(uint64_t flags)
}
static void add_page(unsigned long voffset,
- unsigned long offset, uint64_t flags)
+ unsigned long offset, uint64_t flags, uint64_t pme)
{
- flags = kpageflags_flags(flags);
+ flags = kpageflags_flags(flags, pme);
if (!bit_mask_ok(flags))
return;
@@ -569,7 +576,8 @@ static void add_page(unsigned long voffset,
#define KPAGEFLAGS_BATCH (64 << 10) /* 64k pages */
static void walk_pfn(unsigned long voffset,
unsigned long index,
- unsigned long count)
+ unsigned long count,
+ uint64_t pme)
{
uint64_t buf[KPAGEFLAGS_BATCH];
unsigned long batch;
@@ -583,7 +591,7 @@ static void walk_pfn(unsigned long voffset,
break;
for (i = 0; i < pages; i++)
- add_page(voffset + i, index + i, buf[i]);
+ add_page(voffset + i, index + i, buf[i], pme);
index += pages;
count -= pages;
@@ -608,7 +616,7 @@ static void walk_vma(unsigned long index, unsigned long count)
for (i = 0; i < pages; i++) {
pfn = pagemap_pfn(buf[i]);
if (pfn)
- walk_pfn(index + i, pfn, 1);
+ walk_pfn(index + i, pfn, 1, buf[i]);
}
index += pages;
@@ -659,7 +667,7 @@ static void walk_addr_ranges(void)
for (i = 0; i < nr_addr_ranges; i++)
if (!opt_pid)
- walk_pfn(0, opt_offset[i], opt_size[i]);
+ walk_pfn(0, opt_offset[i], opt_size[i], 0);
else
walk_task(opt_offset[i], opt_size[i]);
--
1.8.3.1
On 10/04/2013 11:02 PM, Naoya Horiguchi wrote:
> This flag shows that soft dirty bit is not enabled yet.
> You can enable it by "echo 4 > /proc/pid/clear_refs."
The comment is not correct. Per-VMA soft-dirty flag means, that
VMA is "newly created" one and thus represents a new (dirty) are
in task's VM.
Other than this -- yes, it's nice to have this flag in smaps.
> Signed-off-by: Naoya Horiguchi <[email protected]>
> ---
> fs/proc/task_mmu.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git v3.12-rc2-mmots-2013-09-24-17-03.orig/fs/proc/task_mmu.c v3.12-rc2-mmots-2013-09-24-17-03/fs/proc/task_mmu.c
> index 7366e9d..c591928 100644
> --- v3.12-rc2-mmots-2013-09-24-17-03.orig/fs/proc/task_mmu.c
> +++ v3.12-rc2-mmots-2013-09-24-17-03/fs/proc/task_mmu.c
> @@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
> [ilog2(VM_NONLINEAR)] = "nl",
> [ilog2(VM_ARCH_1)] = "ar",
> [ilog2(VM_DONTDUMP)] = "dd",
> +#ifdef CONFIG_MEM_SOFT_DIRTY
> + [ilog2(VM_SOFTDIRTY)] = "sd",
> +#endif
> [ilog2(VM_MIXEDMAP)] = "mm",
> [ilog2(VM_HUGEPAGE)] = "hg",
> [ilog2(VM_NOHUGEPAGE)] = "nh",
>
On Mon, Oct 07, 2013 at 05:21:48PM +0400, Pavel Emelyanov wrote:
> On 10/04/2013 11:02 PM, Naoya Horiguchi wrote:
> > This flag shows that soft dirty bit is not enabled yet.
> > You can enable it by "echo 4 > /proc/pid/clear_refs."
>
> The comment is not correct. Per-VMA soft-dirty flag means, that
> VMA is "newly created" one and thus represents a new (dirty) are
> in task's VM.
Thanks for the correction. I changed the description.
Naoya
---
From: Naoya Horiguchi <[email protected]>
Date: Fri, 4 Oct 2013 13:42:13 -0400
Subject: [PATCH] smaps: show VM_SOFTDIRTY flag in VmFlags line
This flag shows that the VMA is "newly created" and thus represents
"dirty" in the task's VM.
You can clear it by "echo 4 > /proc/pid/clear_refs."
Signed-off-by: Naoya Horiguchi <[email protected]>
---
fs/proc/task_mmu.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 7366e9d..c591928 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_NONLINEAR)] = "nl",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_DONTDUMP)] = "dd",
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ [ilog2(VM_SOFTDIRTY)] = "sd",
+#endif
[ilog2(VM_MIXEDMAP)] = "mm",
[ilog2(VM_HUGEPAGE)] = "hg",
[ilog2(VM_NOHUGEPAGE)] = "nh",
--
1.8.3.1
On Mon, Oct 07, 2013 at 10:15:04AM -0400, Naoya Horiguchi wrote:
> >
> > The comment is not correct. Per-VMA soft-dirty flag means, that
> > VMA is "newly created" one and thus represents a new (dirty) are
> > in task's VM.
>
> Thanks for the correction. I changed the description.
Looks good to me, thanks!
Acked-by: Cyrill Gorcunov <[email protected]>
On Fri, 4 Oct 2013 15:02:15 -0400 Naoya Horiguchi <[email protected]> wrote:
> Soft dirty bit allows us to track which pages are written since the
> last clear_ref (by "echo 4 > /proc/pid/clear_refs".) This is useful
> for userspace applications to know their memory footprints.
>
> Note that the kernel exposes this flag via bit[55] of /proc/pid/pagemap,
> and the semantics is not a default one (scheduled to be the default in
> the near future.) However, it shifts to the new semantics at the first
> clear_ref, and the users of soft dirty bit always do it before utilizing
> the bit, so that's not a big deal. Users must avoid relying on the bit
> in page-types before the first clear_ref.
Is Documentation/filesystems/proc.txt (around line 450) fully up to
date here?
On Mon, 07 Oct 2013 10:15:04 -0400 Naoya Horiguchi <[email protected]> wrote:
> From: Naoya Horiguchi <[email protected]>
> Date: Fri, 4 Oct 2013 13:42:13 -0400
> Subject: [PATCH] smaps: show VM_SOFTDIRTY flag in VmFlags line
>
> This flag shows that the VMA is "newly created" and thus represents
> "dirty" in the task's VM.
> You can clear it by "echo 4 > /proc/pid/clear_refs."
>
> Signed-off-by: Naoya Horiguchi <[email protected]>
> ---
> fs/proc/task_mmu.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index 7366e9d..c591928 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
> [ilog2(VM_NONLINEAR)] = "nl",
> [ilog2(VM_ARCH_1)] = "ar",
> [ilog2(VM_DONTDUMP)] = "dd",
> +#ifdef CONFIG_MEM_SOFT_DIRTY
> + [ilog2(VM_SOFTDIRTY)] = "sd",
> +#endif
> [ilog2(VM_MIXEDMAP)] = "mm",
> [ilog2(VM_HUGEPAGE)] = "hg",
> [ilog2(VM_NOHUGEPAGE)] = "nh",
Documentation/filesystems/proc.txt needs updating, please.
On Mon, Oct 07, 2013 at 05:51:25PM -0700, Andrew Morton wrote:
> On Mon, 07 Oct 2013 10:15:04 -0400 Naoya Horiguchi <[email protected]> wrote:
>
> > From: Naoya Horiguchi <[email protected]>
> > Date: Fri, 4 Oct 2013 13:42:13 -0400
> > Subject: [PATCH] smaps: show VM_SOFTDIRTY flag in VmFlags line
> >
> > This flag shows that the VMA is "newly created" and thus represents
> > "dirty" in the task's VM.
> > You can clear it by "echo 4 > /proc/pid/clear_refs."
> >
> > Signed-off-by: Naoya Horiguchi <[email protected]>
> > ---
> > fs/proc/task_mmu.c | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> > index 7366e9d..c591928 100644
> > --- a/fs/proc/task_mmu.c
> > +++ b/fs/proc/task_mmu.c
> > @@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
> > [ilog2(VM_NONLINEAR)] = "nl",
> > [ilog2(VM_ARCH_1)] = "ar",
> > [ilog2(VM_DONTDUMP)] = "dd",
> > +#ifdef CONFIG_MEM_SOFT_DIRTY
> > + [ilog2(VM_SOFTDIRTY)] = "sd",
> > +#endif
> > [ilog2(VM_MIXEDMAP)] = "mm",
> > [ilog2(VM_HUGEPAGE)] = "hg",
> > [ilog2(VM_NOHUGEPAGE)] = "nh",
>
> Documentation/filesystems/proc.txt needs updating, please.
OK. Here's the revised one.
---
From: Naoya Horiguchi <[email protected]>
Date: Mon, 7 Oct 2013 22:52:00 -0400
Subject: [PATCH] smaps: show VM_SOFTDIRTY flag in VmFlags line
This flag shows that the VMA is "newly created" and thus represents
"dirty" in the task's VM.
You can clear it by "echo 4 > /proc/pid/clear_refs."
Signed-off-by: Naoya Horiguchi <[email protected]>
Acked-by: Cyrill Gorcunov <[email protected]>
---
Documentation/filesystems/proc.txt | 1 +
fs/proc/task_mmu.c | 3 +++
2 files changed, 4 insertions(+)
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt
index 823c95f..22d89aa3 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -460,6 +460,7 @@ flags associated with the particular virtual memory area in two letter encoded
nl - non-linear mapping
ar - architecture specific flag
dd - do not include area into core dump
+ sd - soft-dirty flag
mm - mixed map area
hg - huge page advise flag
nh - no-huge page advise flag
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 7366e9d..c591928 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -561,6 +561,9 @@ static void show_smap_vma_flags(struct seq_file *m, struct vm_area_struct *vma)
[ilog2(VM_NONLINEAR)] = "nl",
[ilog2(VM_ARCH_1)] = "ar",
[ilog2(VM_DONTDUMP)] = "dd",
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ [ilog2(VM_SOFTDIRTY)] = "sd",
+#endif
[ilog2(VM_MIXEDMAP)] = "mm",
[ilog2(VM_HUGEPAGE)] = "hg",
[ilog2(VM_NOHUGEPAGE)] = "nh",
--
1.8.3.1
On Mon, Oct 07, 2013 at 05:51:25PM -0700, Andrew Morton wrote:
>
> Documentation/filesystems/proc.txt needs updating, please.
I'll do this today.
On Tue, Oct 08, 2013 at 12:59:01PM +0400, Cyrill Gorcunov wrote:
> On Mon, Oct 07, 2013 at 05:51:25PM -0700, Andrew Morton wrote:
> >
> > Documentation/filesystems/proc.txt needs updating, please.
>
> I'll do this today.
Ouch, it seems I've missed the reply and Naoya already has it done.