* [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
@ 2013-08-20 15:31 Cyrill Gorcunov
2013-08-20 16:57 ` Randy Dunlap
2013-08-20 21:15 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Rob Landley
0 siblings, 2 replies; 8+ messages in thread
From: Cyrill Gorcunov @ 2013-08-20 15:31 UTC (permalink / raw)
To: Andrew Morton
Cc: linux-mm, linux-kernel, Andy Lutomirski, Pavel Emelyanov,
Matt Mackall, Xiao Guangrong, Marcelo Tosatti, KOSAKI Motohiro,
Stephen Rothwell, Peter Zijlstra, Aneesh Kumar K.V
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
---
Documentation/vm/soft-dirty.txt | 7 +++++++
1 file changed, 7 insertions(+)
Index: linux-2.6.git/Documentation/vm/soft-dirty.txt
===================================================================
--- linux-2.6.git.orig/Documentation/vm/soft-dirty.txt
+++ linux-2.6.git/Documentation/vm/soft-dirty.txt
@@ -28,6 +28,13 @@ This is so, since the pages are still ma
the kernel does is finds this fact out and puts both writable and soft-dirty
bits on the PTE.
+ While in most cases tracking memory changes by #PF-s is more than enough
+there is still a scenario when we can loose soft dirty bit -- a task does
+unmap previously mapped memory region and then maps new one exactly at the
+same place. When unmap called the kernel internally clears PTEs values
+including soft dirty bit. To notify user space application about such
+memory region renewal the kernel always mark new memory regions (and
+expanded regions) as soft dirtified.
This feature is actively used by the checkpoint-restore project. You
can find more details about it on http://criu.org
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
2013-08-20 15:31 [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Cyrill Gorcunov
@ 2013-08-20 16:57 ` Randy Dunlap
2013-08-20 17:01 ` Cyrill Gorcunov
2013-08-20 17:06 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v2 Cyrill Gorcunov
2013-08-20 21:15 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Rob Landley
1 sibling, 2 replies; 8+ messages in thread
From: Randy Dunlap @ 2013-08-20 16:57 UTC (permalink / raw)
To: Cyrill Gorcunov
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On 08/20/13 08:31, Cyrill Gorcunov wrote:
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> Cc: Pavel Emelyanov <xemul@parallels.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matt Mackall <mpm@selenic.com>
> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> Cc: Marcelo Tosatti <mtosatti@redhat.com>
> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> ---
> Documentation/vm/soft-dirty.txt | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> Index: linux-2.6.git/Documentation/vm/soft-dirty.txt
> ===================================================================
> --- linux-2.6.git.orig/Documentation/vm/soft-dirty.txt
> +++ linux-2.6.git/Documentation/vm/soft-dirty.txt
> @@ -28,6 +28,13 @@ This is so, since the pages are still ma
> the kernel does is finds this fact out and puts both writable and soft-dirty
> bits on the PTE.
>
> + While in most cases tracking memory changes by #PF-s is more than enough
enough,
> +there is still a scenario when we can loose soft dirty bit -- a task does
lose soft dirty bits -- a task
> +unmap previously mapped memory region and then maps new one exactly at the
unmaps a previously mapped memory region and then maps a new one at exactly the
> +same place. When unmap called the kernel internally clears PTEs values
When unmap is called, the kernel internally clears PTE values
> +including soft dirty bit. To notify user space application about such
bits.
> +memory region renewal the kernel always mark new memory regions (and
marks
> +expanded regions) as soft dirtified.
or: as soft dirty.
>
> This feature is actively used by the checkpoint-restore project. You
> can find more details about it on http://criu.org
> --
--
~Randy
--
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
2013-08-20 16:57 ` Randy Dunlap
@ 2013-08-20 17:01 ` Cyrill Gorcunov
2013-08-20 17:25 ` Randy Dunlap
2013-08-20 17:06 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v2 Cyrill Gorcunov
1 sibling, 1 reply; 8+ messages in thread
From: Cyrill Gorcunov @ 2013-08-20 17:01 UTC (permalink / raw)
To: Randy Dunlap
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On Tue, Aug 20, 2013 at 09:57:38AM -0700, Randy Dunlap wrote:
> >
> > + While in most cases tracking memory changes by #PF-s is more than enough
> enough,
?
For the rest -- thanks a LOT Randy, I'll update.
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^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v2
2013-08-20 16:57 ` Randy Dunlap
2013-08-20 17:01 ` Cyrill Gorcunov
@ 2013-08-20 17:06 ` Cyrill Gorcunov
1 sibling, 0 replies; 8+ messages in thread
From: Cyrill Gorcunov @ 2013-08-20 17:06 UTC (permalink / raw)
To: Randy Dunlap
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
Here is updated one, thanks again.
---
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: [PATCH] docs: Document soft dirty behaviour for freshly created memory regions
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
---
Documentation/vm/soft-dirty.txt | 7 +++++++
1 file changed, 7 insertions(+)
Index: linux-2.6.git/Documentation/vm/soft-dirty.txt
===================================================================
--- linux-2.6.git.orig/Documentation/vm/soft-dirty.txt
+++ linux-2.6.git/Documentation/vm/soft-dirty.txt
@@ -28,6 +28,13 @@ This is so, since the pages are still ma
the kernel does is finds this fact out and puts both writable and soft-dirty
bits on the PTE.
+ While in most cases tracking memory changes by #PF-s is more than enough
+there is still a scenario when we can lose soft dirty bits -- a task
+unmaps a previously mapped memory region and then maps a new one at exactly
+the same place. When unmap is called, the kernel internally clears PTE values
+including soft dirty bits. To notify user space application about such
+memory region renewal the kernel always marks new memory regions (and
+expanded regions) as soft dirty.
This feature is actively used by the checkpoint-restore project. You
can find more details about it on http://criu.org
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
2013-08-20 17:01 ` Cyrill Gorcunov
@ 2013-08-20 17:25 ` Randy Dunlap
2013-08-20 18:13 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v3 Cyrill Gorcunov
0 siblings, 1 reply; 8+ messages in thread
From: Randy Dunlap @ 2013-08-20 17:25 UTC (permalink / raw)
To: Cyrill Gorcunov
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On 08/20/13 10:01, Cyrill Gorcunov wrote:
> On Tue, Aug 20, 2013 at 09:57:38AM -0700, Randy Dunlap wrote:
>>>
>>> + While in most cases tracking memory changes by #PF-s is more than enough
>> enough,
>
> ?
Long introductory phrases usually merit a comma after them.
>
> For the rest -- thanks a LOT Randy, I'll update.
> --
--
~Randy
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^ permalink raw reply [flat|nested] 8+ messages in thread
* [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v3
2013-08-20 17:25 ` Randy Dunlap
@ 2013-08-20 18:13 ` Cyrill Gorcunov
0 siblings, 0 replies; 8+ messages in thread
From: Cyrill Gorcunov @ 2013-08-20 18:13 UTC (permalink / raw)
To: Randy Dunlap
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On Tue, Aug 20, 2013 at 10:25:11AM -0700, Randy Dunlap wrote:
>
> Long introductory phrases usually merit a comma after them.
Ah, I see, thanks!
---
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: [PATCH] docs: Document soft dirty behaviour for freshly created memory regions
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
---
Documentation/vm/soft-dirty.txt | 7 +++++++
1 file changed, 7 insertions(+)
Index: linux-2.6.git/Documentation/vm/soft-dirty.txt
===================================================================
--- linux-2.6.git.orig/Documentation/vm/soft-dirty.txt
+++ linux-2.6.git/Documentation/vm/soft-dirty.txt
@@ -28,6 +28,13 @@ This is so, since the pages are still ma
the kernel does is finds this fact out and puts both writable and soft-dirty
bits on the PTE.
+ While in most cases tracking memory changes by #PF-s is more than enough,
+there is still a scenario when we can lose soft dirty bits -- a task
+unmaps a previously mapped memory region and then maps a new one at exactly
+the same place. When unmap is called, the kernel internally clears PTE values
+including soft dirty bits. To notify user space application about such
+memory region renewal the kernel always marks new memory regions (and
+expanded regions) as soft dirty.
This feature is actively used by the checkpoint-restore project. You
can find more details about it on http://criu.org
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
2013-08-20 15:31 [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Cyrill Gorcunov
2013-08-20 16:57 ` Randy Dunlap
@ 2013-08-20 21:15 ` Rob Landley
2013-08-20 21:43 ` Cyrill Gorcunov
1 sibling, 1 reply; 8+ messages in thread
From: Rob Landley @ 2013-08-20 21:15 UTC (permalink / raw)
To: Cyrill Gorcunov
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On 08/20/2013 10:31:32 AM, Cyrill Gorcunov wrote:
> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> Cc: Pavel Emelyanov <xemul@parallels.com>
> Cc: Andy Lutomirski <luto@amacapital.net>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Matt Mackall <mpm@selenic.com>
> Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> Cc: Marcelo Tosatti <mtosatti@redhat.com>
> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
With that cc: list, I'll assume you do _not_ want the Documentation
maintainer paying attention to it.
Rob
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^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions
2013-08-20 21:15 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Rob Landley
@ 2013-08-20 21:43 ` Cyrill Gorcunov
0 siblings, 0 replies; 8+ messages in thread
From: Cyrill Gorcunov @ 2013-08-20 21:43 UTC (permalink / raw)
To: Rob Landley
Cc: Andrew Morton, linux-mm, linux-kernel, Andy Lutomirski,
Pavel Emelyanov, Matt Mackall, Xiao Guangrong, Marcelo Tosatti,
KOSAKI Motohiro, Stephen Rothwell, Peter Zijlstra,
Aneesh Kumar K.V
On Tue, Aug 20, 2013 at 04:15:53PM -0500, Rob Landley wrote:
> On 08/20/2013 10:31:32 AM, Cyrill Gorcunov wrote:
> >Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
> >Cc: Pavel Emelyanov <xemul@parallels.com>
> >Cc: Andy Lutomirski <luto@amacapital.net>
> >Cc: Andrew Morton <akpm@linux-foundation.org>
> >Cc: Matt Mackall <mpm@selenic.com>
> >Cc: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
> >Cc: Marcelo Tosatti <mtosatti@redhat.com>
> >Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
> >Cc: Stephen Rothwell <sfr@canb.auug.org.au>
> >Cc: Peter Zijlstra <peterz@infradead.org>
> >Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
>
> With that cc: list, I'll assume you do _not_ want the Documentation
> maintainer paying attention to it.
Hmm, I must admit I don't know whis else list should be CC'ed.
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^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-08-20 21:43 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2013-08-20 15:31 [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Cyrill Gorcunov
2013-08-20 16:57 ` Randy Dunlap
2013-08-20 17:01 ` Cyrill Gorcunov
2013-08-20 17:25 ` Randy Dunlap
2013-08-20 18:13 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v3 Cyrill Gorcunov
2013-08-20 17:06 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions, v2 Cyrill Gorcunov
2013-08-20 21:15 ` [PATCH -mm] docs: Document soft dirty behaviour for freshly created memory regions Rob Landley
2013-08-20 21:43 ` Cyrill Gorcunov
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