[PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Jason Liu]

when run the folloing command under shell, it will return error
sh/$ echo 1 > /proc/sys/vm/compact_memory
sh/$ sh: write error: Bad address

After strace, I found the following log:
...
write(1, "1\n", 2)               = 3
write(1, "", 4294967295)         = -1 EFAULT (Bad address)
write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
) = 31

This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.

The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
sysctl_compaction_handler after compaction_nodes finished.

Suggested-by:David Rientjes <rientjes@google.com>
Cc:Mel Gorman <mgorman@suse.de>
Cc:Andrew Morton <akpm@linux-foundation.org>
Cc:Rik van Riel <riel@redhat.com>
Cc:Minchan Kim <minchan@kernel.org>
Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Jason Liu <r64343@freescale.com>
---
 mm/compaction.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/mm/compaction.c b/mm/compaction.c
index 6b807e4..f8f5c11 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1210,7 +1210,7 @@ static int compact_node(int nid)
 }
 
 /* Compact all nodes in the system */
-static int compact_nodes(void)
+static void compact_nodes(void)
 {
 	int nid;
 
@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
 
 	for_each_online_node(nid)
 		compact_node(nid);
-
-	return COMPACT_COMPLETE;
 }
 
 /* The written value is actually unused, all memory is compacted */
@@ -1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write,
 			void __user *buffer, size_t *length, loff_t *ppos)
 {
 	if (write)
-		return compact_nodes();
+		compact_nodes();
 
 	return 0;
 }
-- 
1.7.5.4


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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Wanpeng Li]

On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:

Hi Jason,

>when run the folloing command under shell, it will return error
>sh/$ echo 1 > /proc/sys/vm/compact_memory
>sh/$ sh: write error: Bad address
>

How can you modify the value through none privileged user since the mode == 0200?

>After strace, I found the following log:
>...
>write(1, "1\n", 2)               = 3
>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
>) = 31
>
>This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.
>
>The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
>sysctl_compaction_handler after compaction_nodes finished.

What's the special scenario you are in? I couldn't figure out the
similar error against latest 3.8-rc2, how could you reproduce it?

Regards,
Wanpeng Li 

>
>Suggested-by:David Rientjes <rientjes@google.com>
>Cc:Mel Gorman <mgorman@suse.de>
>Cc:Andrew Morton <akpm@linux-foundation.org>
>Cc:Rik van Riel <riel@redhat.com>
>Cc:Minchan Kim <minchan@kernel.org>
>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>Signed-off-by: Jason Liu <r64343@freescale.com>
>---
> mm/compaction.c |    6 ++----
> 1 files changed, 2 insertions(+), 4 deletions(-)
>
>diff --git a/mm/compaction.c b/mm/compaction.c
>index 6b807e4..f8f5c11 100644
>--- a/mm/compaction.c
>+++ b/mm/compaction.c
>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)
> }
>
> /* Compact all nodes in the system */
>-static int compact_nodes(void)
>+static void compact_nodes(void)
> {
> 	int nid;
>
>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>
> 	for_each_online_node(nid)
> 		compact_node(nid);
>-
>-	return COMPACT_COMPLETE;
> }
>
> /* The written value is actually unused, all memory is compacted */
>@@ -1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write,
> 			void __user *buffer, size_t *length, loff_t *ppos)
> {
> 	if (write)
>-		return compact_nodes();
>+		compact_nodes();
>
> 	return 0;
> }
>-- 
>1.7.5.4
>
>
>--
>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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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Wanpeng Li]

On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:

Hi Jason,

>when run the folloing command under shell, it will return error
>sh/$ echo 1 > /proc/sys/vm/compact_memory
>sh/$ sh: write error: Bad address
>

How can you modify the value through none privileged user since the mode == 0200?

>After strace, I found the following log:
>...
>write(1, "1\n", 2)               = 3
>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
>) = 31
>
>This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.
>
>The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
>sysctl_compaction_handler after compaction_nodes finished.

What's the special scenario you are in? I couldn't figure out the
similar error against latest 3.8-rc2, how could you reproduce it?

Regards,
Wanpeng Li 

>
>Suggested-by:David Rientjes <rientjes@google.com>
>Cc:Mel Gorman <mgorman@suse.de>
>Cc:Andrew Morton <akpm@linux-foundation.org>
>Cc:Rik van Riel <riel@redhat.com>
>Cc:Minchan Kim <minchan@kernel.org>
>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>Signed-off-by: Jason Liu <r64343@freescale.com>
>---
> mm/compaction.c |    6 ++----
> 1 files changed, 2 insertions(+), 4 deletions(-)
>
>diff --git a/mm/compaction.c b/mm/compaction.c
>index 6b807e4..f8f5c11 100644
>--- a/mm/compaction.c
>+++ b/mm/compaction.c
>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)
> }
>
> /* Compact all nodes in the system */
>-static int compact_nodes(void)
>+static void compact_nodes(void)
> {
> 	int nid;
>
>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>
> 	for_each_online_node(nid)
> 		compact_node(nid);
>-
>-	return COMPACT_COMPLETE;
> }
>
> /* The written value is actually unused, all memory is compacted */
>@@ -1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table, int write,
> 			void __user *buffer, size_t *length, loff_t *ppos)
> {
> 	if (write)
>-		return compact_nodes();
>+		compact_nodes();
>
> 	return 0;
> }
>-- 
>1.7.5.4
>
>
>--
>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>

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RE: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Liu Hui-R64343]

>-----Original Message-----
>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>Sent: Sunday, January 06, 2013 4:00 PM
>To: Liu Hui-R64343
>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>foundation.org; riel@redhat.com; minchan@kernel.org;
>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
>error issue
>
>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
>
>Hi Jason,
>
>>when run the folloing command under shell, it will return error sh/$
>>echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address
>>
>
>How can you modify the value through none privileged user since the mode
>== 0200?

I write it through privileged user(root). I'm using the GNOME_Mobile rootfs.

>
>>After strace, I found the following log:
>>...
>>write(1, "1\n", 2)               = 3
>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad
>>address
>>) = 31
>>
>>This tells system return 3(COMPACT_COMPLETE) after write data to
>compact_memory.
>>
>>The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE)
>>from sysctl_compaction_handler after compaction_nodes finished.
>
>What's the special scenario you are in? I couldn't figure out the similar error
>against latest 3.8-rc2, how could you reproduce it?

I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the issue: 100%.

root@freescale /$ sh


BusyBox v1.20.2 () built-in shell (ash)
Enter 'help' for a list of built-in commands.

Could you run strace and see the log:  strace echo 1 > /proc/sys/vm/compact_memory

>
>Regards,
>Wanpeng Li
>
>>
>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-foundation.org>
>Cc:Rik
>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>Signed-off-by: Jason Liu <r64343@freescale.com>
>>---
>> mm/compaction.c |    6 ++----
>> 1 files changed, 2 insertions(+), 4 deletions(-)
>>
>>diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11
>>100644
>>--- a/mm/compaction.c
>>+++ b/mm/compaction.c
>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
>>
>> /* Compact all nodes in the system */
>>-static int compact_nodes(void)
>>+static void compact_nodes(void)
>> {
>> 	int nid;
>>
>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>>
>> 	for_each_online_node(nid)
>> 		compact_node(nid);
>>-
>>-	return COMPACT_COMPLETE;
>> }
>>
>> /* The written value is actually unused, all memory is compacted */ @@
>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table,
>int write,
>> 			void __user *buffer, size_t *length, loff_t *ppos)  {
>> 	if (write)
>>-		return compact_nodes();
>>+		compact_nodes();
>>
>> 	return 0;
>> }
>>--
>>1.7.5.4
>>
>>
>>--
>>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>
>


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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Wanpeng Li]

On Sun, Jan 06, 2013 at 08:11:58AM +0000, Liu Hui-R64343 wrote:
>>-----Original Message-----
>>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>>Sent: Sunday, January 06, 2013 4:00 PM
>>To: Liu Hui-R64343
>>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>>foundation.org; riel@redhat.com; minchan@kernel.org;
>>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
>>error issue
>>
>>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
>>
>>Hi Jason,
>>
>>>when run the folloing command under shell, it will return error sh/$
>>>echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address
>>>
>>
>>How can you modify the value through none privileged user since the mode
>>== 0200?
>
>I write it through privileged user(root). I'm using the GNOME_Mobile rootfs.
>
>>
>>>After strace, I found the following log:
>>>...
>>>write(1, "1\n", 2)               = 3
>>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>>>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad
>>>address
>>>) = 31
>>>
>>>This tells system return 3(COMPACT_COMPLETE) after write data to
>>compact_memory.
>>>
>>>The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE)
>>>from sysctl_compaction_handler after compaction_nodes finished.
>>
>>What's the special scenario you are in? I couldn't figure out the similar error
>>against latest 3.8-rc2, how could you reproduce it?
>
>I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the issue: 100%.
>
>root@freescale /$ sh
>
>
>BusyBox v1.20.2 () built-in shell (ash)
>Enter 'help' for a list of built-in commands.
>
>Could you run strace and see the log:  strace echo 1 > /proc/sys/vm/compact_memory
>

I test it on my desktop against latest 3.8-rc2, can't repoduce it. :)

write(1, "1\n", 2)                      = 3
close(1)                                = 0
munmap(0xb779c000, 4096)                = 0
close(2)                                = 0
exit_group(0)                           = ?
+++ exited with 0 +++

Regards,
Wanpeng Li 

>>
>>Regards,
>>Wanpeng Li
>>
>>>
>>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
>>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-foundation.org>
>>Cc:Rik
>>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
>>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>>Signed-off-by: Jason Liu <r64343@freescale.com>
>>>---
>>> mm/compaction.c |    6 ++----
>>> 1 files changed, 2 insertions(+), 4 deletions(-)
>>>
>>>diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11
>>>100644
>>>--- a/mm/compaction.c
>>>+++ b/mm/compaction.c
>>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
>>>
>>> /* Compact all nodes in the system */
>>>-static int compact_nodes(void)
>>>+static void compact_nodes(void)
>>> {
>>> 	int nid;
>>>
>>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>>>
>>> 	for_each_online_node(nid)
>>> 		compact_node(nid);
>>>-
>>>-	return COMPACT_COMPLETE;
>>> }
>>>
>>> /* The written value is actually unused, all memory is compacted */ @@
>>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table,
>>int write,
>>> 			void __user *buffer, size_t *length, loff_t *ppos)  {
>>> 	if (write)
>>>-		return compact_nodes();
>>>+		compact_nodes();
>>>
>>> 	return 0;
>>> }
>>>--
>>>1.7.5.4
>>>
>>>
>>>--
>>>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>
>>
>

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RE: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Liu Hui-R64343]

>-----Original Message-----
>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>Sent: Sunday, January 06, 2013 4:46 PM
>To: Liu Hui-R64343
>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>foundation.org; riel@redhat.com; minchan@kernel.org;
>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
>error issue
>
>On Sun, Jan 06, 2013 at 08:11:58AM +0000, Liu Hui-R64343 wrote:
>>>-----Original Message-----
>>>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>>>Sent: Sunday, January 06, 2013 4:00 PM
>>>To: Liu Hui-R64343
>>>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>>>foundation.org; riel@redhat.com; minchan@kernel.org;
>>>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>>>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory
>>>return error issue
>>>
>>>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
>>>
>>>Hi Jason,
>>>
>>>>when run the folloing command under shell, it will return error sh/$
>>>>echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad
>>>>address
>>>>
>>>
>>>How can you modify the value through none privileged user since the
>>>mode == 0200?
>>
>>I write it through privileged user(root). I'm using the GNOME_Mobile rootfs.
>>
>>>
>>>>After strace, I found the following log:
>>>>...
>>>>write(1, "1\n", 2)               = 3
>>>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>>>>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad
>>>>address
>>>>) = 31
>>>>
>>>>This tells system return 3(COMPACT_COMPLETE) after write data to
>>>compact_memory.
>>>>
>>>>The fix is to make the system just return 0 instead
>>>>3(COMPACT_COMPLETE) from sysctl_compaction_handler after
>compaction_nodes finished.
>>>
>>>What's the special scenario you are in? I couldn't figure out the
>>>similar error against latest 3.8-rc2, how could you reproduce it?
>>
>>I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the issue:
>100%.
>>
>>root@freescale /$ sh
>>
>>
>>BusyBox v1.20.2 () built-in shell (ash) Enter 'help' for a list of
>>built-in commands.
>>
>>Could you run strace and see the log:  strace echo 1 >
>>/proc/sys/vm/compact_memory
>>
>
>I test it on my desktop against latest 3.8-rc2, can't repoduce it. :)
>
>write(1, "1\n", 2)                      = 3

Here it tells it.  

>close(1)                                = 0
>munmap(0xb779c000, 4096)                = 0
>close(2)                                = 0
>exit_group(0)                           = ?
>+++ exited with 0 +++
>
>Regards,
>Wanpeng Li
>
>>>
>>>Regards,
>>>Wanpeng Li
>>>
>>>>
>>>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
>>>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-foundation.org>
>>>Cc:Rik
>>>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
>>>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>>>Signed-off-by: Jason Liu <r64343@freescale.com>
>>>>---
>>>> mm/compaction.c |    6 ++----
>>>> 1 files changed, 2 insertions(+), 4 deletions(-)
>>>>
>>>>diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11
>>>>100644
>>>>--- a/mm/compaction.c
>>>>+++ b/mm/compaction.c
>>>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
>>>>
>>>> /* Compact all nodes in the system */ -static int
>>>>compact_nodes(void)
>>>>+static void compact_nodes(void)
>>>> {
>>>> 	int nid;
>>>>
>>>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>>>>
>>>> 	for_each_online_node(nid)
>>>> 		compact_node(nid);
>>>>-
>>>>-	return COMPACT_COMPLETE;
>>>> }
>>>>
>>>> /* The written value is actually unused, all memory is compacted */
>>>>@@
>>>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table
>>>>*table,
>>>int write,
>>>> 			void __user *buffer, size_t *length, loff_t *ppos)  {
>>>> 	if (write)
>>>>-		return compact_nodes();
>>>>+		compact_nodes();
>>>>
>>>> 	return 0;
>>>> }
>>>>--
>>>>1.7.5.4
>>>>
>>>>
>>>>--
>>>>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>
>>>
>>
>


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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Simon Jeons]

On Sun, 2013-01-06 at 08:48 +0000, Liu Hui-R64343 wrote:
> >-----Original Message-----
> >From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
> >Sent: Sunday, January 06, 2013 4:46 PM
> >To: Liu Hui-R64343
> >Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
> >foundation.org; riel@redhat.com; minchan@kernel.org;
> >kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
> >Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
> >error issue
> >
> >On Sun, Jan 06, 2013 at 08:11:58AM +0000, Liu Hui-R64343 wrote:
> >>>-----Original Message-----
> >>>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
> >>>Sent: Sunday, January 06, 2013 4:00 PM
> >>>To: Liu Hui-R64343
> >>>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
> >>>foundation.org; riel@redhat.com; minchan@kernel.org;
> >>>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
> >>>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory
> >>>return error issue
> >>>
> >>>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
> >>>
> >>>Hi Jason,
> >>>
> >>>>when run the folloing command under shell, it will return error sh/$
> >>>>echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad
> >>>>address
> >>>>
> >>>
> >>>How can you modify the value through none privileged user since the
> >>>mode == 0200?
> >>
> >>I write it through privileged user(root). I'm using the GNOME_Mobile rootfs.
> >>
> >>>
> >>>>After strace, I found the following log:
> >>>>...
> >>>>write(1, "1\n", 2)               = 3
> >>>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
> >>>>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad
> >>>>address
> >>>>) = 31
> >>>>
> >>>>This tells system return 3(COMPACT_COMPLETE) after write data to
> >>>compact_memory.
> >>>>
> >>>>The fix is to make the system just return 0 instead
> >>>>3(COMPACT_COMPLETE) from sysctl_compaction_handler after
> >compaction_nodes finished.
> >>>
> >>>What's the special scenario you are in? I couldn't figure out the
> >>>similar error against latest 3.8-rc2, how could you reproduce it?
> >>
> >>I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the issue:
> >100%.
> >>
> >>root@freescale /$ sh
> >>
> >>
> >>BusyBox v1.20.2 () built-in shell (ash) Enter 'help' for a list of
> >>built-in commands.
> >>
> >>Could you run strace and see the log:  strace echo 1 >
> >>/proc/sys/vm/compact_memory
> >>
> >
> >I test it on my desktop against latest 3.8-rc2, can't repoduce it. :)
> >
> >write(1, "1\n", 2)                      = 3
> 
> Here it tells it.  

Why this value trouble you?

> 
> >close(1)                                = 0
> >munmap(0xb779c000, 4096)                = 0
> >close(2)                                = 0
> >exit_group(0)                           = ?
> >+++ exited with 0 +++
> >
> >Regards,
> >Wanpeng Li
> >
> >>>
> >>>Regards,
> >>>Wanpeng Li
> >>>
> >>>>
> >>>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
> >>>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-foundation.org>
> >>>Cc:Rik
> >>>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
> >>>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> >>>>Signed-off-by: Jason Liu <r64343@freescale.com>
> >>>>---
> >>>> mm/compaction.c |    6 ++----
> >>>> 1 files changed, 2 insertions(+), 4 deletions(-)
> >>>>
> >>>>diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11
> >>>>100644
> >>>>--- a/mm/compaction.c
> >>>>+++ b/mm/compaction.c
> >>>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
> >>>>
> >>>> /* Compact all nodes in the system */ -static int
> >>>>compact_nodes(void)
> >>>>+static void compact_nodes(void)
> >>>> {
> >>>> 	int nid;
> >>>>
> >>>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
> >>>>
> >>>> 	for_each_online_node(nid)
> >>>> 		compact_node(nid);
> >>>>-
> >>>>-	return COMPACT_COMPLETE;
> >>>> }
> >>>>
> >>>> /* The written value is actually unused, all memory is compacted */
> >>>>@@
> >>>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table
> >>>>*table,
> >>>int write,
> >>>> 			void __user *buffer, size_t *length, loff_t *ppos)  {
> >>>> 	if (write)
> >>>>-		return compact_nodes();
> >>>>+		compact_nodes();
> >>>>
> >>>> 	return 0;
> >>>> }
> >>>>--
> >>>>1.7.5.4
> >>>>
> >>>>
> >>>>--
> >>>>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>
> >>>
> >>
> >
> 
> 
> --
> 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>


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RE: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Liu Hui-R64343]

>-----Original Message-----
>From: Simon Jeons [mailto:simon.jeons@gmail.com]
>Sent: Sunday, January 06, 2013 5:20 PM
>To: Liu Hui-R64343
>Cc: Wanpeng Li; linux-kernel@vger.kernel.org; mgorman@suse.de;
>akpm@linux-foundation.org; riel@redhat.com; minchan@kernel.org;
>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
>error issue
>
>On Sun, 2013-01-06 at 08:48 +0000, Liu Hui-R64343 wrote:
>> >-----Original Message-----
>> >From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>> >Sent: Sunday, January 06, 2013 4:46 PM
>> >To: Liu Hui-R64343
>> >Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>> >foundation.org; riel@redhat.com; minchan@kernel.org;
>> >kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>> >Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory
>> >return error issue
>> >
>> >On Sun, Jan 06, 2013 at 08:11:58AM +0000, Liu Hui-R64343 wrote:
>> >>>-----Original Message-----
>> >>>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>> >>>Sent: Sunday, January 06, 2013 4:00 PM
>> >>>To: Liu Hui-R64343
>> >>>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>> >>>foundation.org; riel@redhat.com; minchan@kernel.org;
>> >>>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>> >>>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory
>> >>>return error issue
>> >>>
>> >>>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
>> >>>
>> >>>Hi Jason,
>> >>>
>> >>>>when run the folloing command under shell, it will return error
>> >>>>sh/$ echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error:
>> >>>>Bad address
>> >>>>
>> >>>
>> >>>How can you modify the value through none privileged user since the
>> >>>mode == 0200?
>> >>
>> >>I write it through privileged user(root). I'm using the GNOME_Mobile
>rootfs.
>> >>
>> >>>
>> >>>>After strace, I found the following log:
>> >>>>...
>> >>>>write(1, "1\n", 2)               = 3
>> >>>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>> >>>>write(2, "echo: write error: Bad address\n", 31echo: write error:
>> >>>>Bad address
>> >>>>) = 31
>> >>>>
>> >>>>This tells system return 3(COMPACT_COMPLETE) after write data to
>> >>>compact_memory.
>> >>>>
>> >>>>The fix is to make the system just return 0 instead
>> >>>>3(COMPACT_COMPLETE) from sysctl_compaction_handler after
>> >compaction_nodes finished.
>> >>>
>> >>>What's the special scenario you are in? I couldn't figure out the
>> >>>similar error against latest 3.8-rc2, how could you reproduce it?
>> >>
>> >>I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the
>issue:
>> >100%.
>> >>
>> >>root@freescale /$ sh
>> >>
>> >>
>> >>BusyBox v1.20.2 () built-in shell (ash) Enter 'help' for a list of
>> >>built-in commands.
>> >>
>> >>Could you run strace and see the log:  strace echo 1 >
>> >>/proc/sys/vm/compact_memory
>> >>
>> >
>> >I test it on my desktop against latest 3.8-rc2, can't repoduce it. :)
>> >
>> >write(1, "1\n", 2)                      = 3
>>
>> Here it tells it.
>
>Why this value trouble you?

root@freescale /$strace echo 1 > /proc/sys/vm/compact_memory

write(1, "1\n", 2)                              = 3
write(1, "", 4294967295)                = -1 EFAULT (Bad address)
write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
) = 31

root@freescale /$ sh


BusyBox v1.20.2 () built-in shell (ash)
Enter 'help' for a list of built-in commands.

root@freescale /$  echo 1 > /proc/sys/vm/compact_memory
sh: write error: Bad address

>
>>
>> >close(1)                                = 0
>> >munmap(0xb779c000, 4096)                = 0
>> >close(2)                                = 0
>> >exit_group(0)                           = ?
>> >+++ exited with 0 +++
>> >
>> >Regards,
>> >Wanpeng Li
>> >
>> >>>
>> >>>Regards,
>> >>>Wanpeng Li
>> >>>
>> >>>>
>> >>>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
>> >>>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-
>foundation.org>
>> >>>Cc:Rik
>> >>>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
>> >>>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>> >>>>Signed-off-by: Jason Liu <r64343@freescale.com>
>> >>>>---
>> >>>> mm/compaction.c |    6 ++----
>> >>>> 1 files changed, 2 insertions(+), 4 deletions(-)
>> >>>>
>> >>>>diff --git a/mm/compaction.c b/mm/compaction.c index
>> >>>>6b807e4..f8f5c11
>> >>>>100644
>> >>>>--- a/mm/compaction.c
>> >>>>+++ b/mm/compaction.c
>> >>>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
>> >>>>
>> >>>> /* Compact all nodes in the system */ -static int
>> >>>>compact_nodes(void)
>> >>>>+static void compact_nodes(void)
>> >>>> {
>> >>>> 	int nid;
>> >>>>
>> >>>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>> >>>>
>> >>>> 	for_each_online_node(nid)
>> >>>> 		compact_node(nid);
>> >>>>-
>> >>>>-	return COMPACT_COMPLETE;
>> >>>> }
>> >>>>
>> >>>> /* The written value is actually unused, all memory is compacted
>> >>>>*/ @@
>> >>>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table
>> >>>>*table,
>> >>>int write,
>> >>>> 			void __user *buffer, size_t *length, loff_t *ppos)
>{
>> >>>> 	if (write)
>> >>>>-		return compact_nodes();
>> >>>>+		compact_nodes();
>> >>>>
>> >>>> 	return 0;
>> >>>> }
>> >>>>--
>> >>>>1.7.5.4
>> >>>>
>> >>>>
>> >>>>--
>> >>>>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>
>> >>>
>> >>
>> >
>>
>>
>> --
>> 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>
>
>

Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Michal Nazarewicz]

[-- Attachment #1: Type: text/plain, Size: 561 bytes --]

On Sun, Jan 06 2013, Simon Jeons wrote:
>> >write(1, "1\n", 2)                      = 3

>> Here it tells it.  

> On Sun, 2013-01-06 at 08:48 +0000, Liu Hui-R64343 wrote:
> Why this value trouble you?

Because write() is supposed to return the number of bytes successfully
written.

-- 
Best regards,                                         _     _
.o. | Liege of Serenely Enlightened Majesty of      o' \,=./ `o
..o | Computer Science,  Michał “mina86” Nazarewicz    (o o)
ooo +----<email/xmpp: mpn@google.com>--------------ooO--(_)--Ooo--

[-- Attachment #2.1: Type: text/plain, Size: 0 bytes --]



[-- Attachment #2.2: Type: application/pgp-signature, Size: 835 bytes --]

Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Wanpeng Li]

On Sun, Jan 06, 2013 at 08:11:58AM +0000, Liu Hui-R64343 wrote:
>>-----Original Message-----
>>From: Wanpeng Li [mailto:liwanp@linux.vnet.ibm.com]
>>Sent: Sunday, January 06, 2013 4:00 PM
>>To: Liu Hui-R64343
>>Cc: linux-kernel@vger.kernel.org; mgorman@suse.de; akpm@linux-
>>foundation.org; riel@redhat.com; minchan@kernel.org;
>>kamezawa.hiroyu@jp.fujitsu.com; linux-mm@kvack.org
>>Subject: Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return
>>error issue
>>
>>On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
>>
>>Hi Jason,
>>
>>>when run the folloing command under shell, it will return error sh/$
>>>echo 1 > /proc/sys/vm/compact_memory sh/$ sh: write error: Bad address
>>>
>>
>>How can you modify the value through none privileged user since the mode
>>== 0200?
>
>I write it through privileged user(root). I'm using the GNOME_Mobile rootfs.
>
>>
>>>After strace, I found the following log:
>>>...
>>>write(1, "1\n", 2)               = 3
>>>write(1, "", 4294967295)         = -1 EFAULT (Bad address)
>>>write(2, "echo: write error: Bad address\n", 31echo: write error: Bad
>>>address
>>>) = 31
>>>
>>>This tells system return 3(COMPACT_COMPLETE) after write data to
>>compact_memory.
>>>
>>>The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE)
>>>from sysctl_compaction_handler after compaction_nodes finished.
>>
>>What's the special scenario you are in? I couldn't figure out the similar error
>>against latest 3.8-rc2, how could you reproduce it?
>
>I'm using the BusyBox v1.20.2 () built-in shell (ash), it reproduces the issue: 100%.
>
>root@freescale /$ sh
>
>
>BusyBox v1.20.2 () built-in shell (ash)
>Enter 'help' for a list of built-in commands.
>
>Could you run strace and see the log:  strace echo 1 > /proc/sys/vm/compact_memory
>

I test it on my desktop against latest 3.8-rc2, can't repoduce it. :)

write(1, "1\n", 2)                      = 3
close(1)                                = 0
munmap(0xb779c000, 4096)                = 0
close(2)                                = 0
exit_group(0)                           = ?
+++ exited with 0 +++

Regards,
Wanpeng Li 

>>
>>Regards,
>>Wanpeng Li
>>
>>>
>>>Suggested-by:David Rientjes <rientjes@google.com> Cc:Mel Gorman
>>><mgorman@suse.de> Cc:Andrew Morton <akpm@linux-foundation.org>
>>Cc:Rik
>>>van Riel <riel@redhat.com> Cc:Minchan Kim <minchan@kernel.org>
>>>Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
>>>Signed-off-by: Jason Liu <r64343@freescale.com>
>>>---
>>> mm/compaction.c |    6 ++----
>>> 1 files changed, 2 insertions(+), 4 deletions(-)
>>>
>>>diff --git a/mm/compaction.c b/mm/compaction.c index 6b807e4..f8f5c11
>>>100644
>>>--- a/mm/compaction.c
>>>+++ b/mm/compaction.c
>>>@@ -1210,7 +1210,7 @@ static int compact_node(int nid)  }
>>>
>>> /* Compact all nodes in the system */
>>>-static int compact_nodes(void)
>>>+static void compact_nodes(void)
>>> {
>>> 	int nid;
>>>
>>>@@ -1219,8 +1219,6 @@ static int compact_nodes(void)
>>>
>>> 	for_each_online_node(nid)
>>> 		compact_node(nid);
>>>-
>>>-	return COMPACT_COMPLETE;
>>> }
>>>
>>> /* The written value is actually unused, all memory is compacted */ @@
>>>-1231,7 +1229,7 @@ int sysctl_compaction_handler(struct ctl_table *table,
>>int write,
>>> 			void __user *buffer, size_t *length, loff_t *ppos)  {
>>> 	if (write)
>>>-		return compact_nodes();
>>>+		compact_nodes();
>>>
>>> 	return 0;
>>> }
>>>--
>>>1.7.5.4
>>>
>>>
>>>--
>>>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>
>>
>

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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Mel Gorman]

On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
> when run the folloing command under shell, it will return error
> sh/$ echo 1 > /proc/sys/vm/compact_memory
> sh/$ sh: write error: Bad address
> 
> After strace, I found the following log:
> ...
> write(1, "1\n", 2)               = 3
> write(1, "", 4294967295)         = -1 EFAULT (Bad address)
> write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
> ) = 31
> 
> This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.
> 
> The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
> sysctl_compaction_handler after compaction_nodes finished.
> 
> Suggested-by:David Rientjes <rientjes@google.com>
> Cc:Mel Gorman <mgorman@suse.de>
> Cc:Andrew Morton <akpm@linux-foundation.org>
> Cc:Rik van Riel <riel@redhat.com>
> Cc:Minchan Kim <minchan@kernel.org>
> Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Signed-off-by: Jason Liu <r64343@freescale.com>

Acked-by: Mel Gorman <mgorman@suse.de>

-- 
Mel Gorman
SUSE Labs

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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[Andrew Morton]

On Mon, 7 Jan 2013 13:57:21 +0000
Mel Gorman <mgorman@suse.de> wrote:

> On Sun, Jan 06, 2013 at 03:44:33PM +0800, Jason Liu wrote:
> > when run the folloing command under shell, it will return error
> > sh/$ echo 1 > /proc/sys/vm/compact_memory
> > sh/$ sh: write error: Bad address
> > 
> > After strace, I found the following log:
> > ...
> > write(1, "1\n", 2)               = 3
> > write(1, "", 4294967295)         = -1 EFAULT (Bad address)
> > write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
> > ) = 31
> > 
> > This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.
> > 
> > The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
> > sysctl_compaction_handler after compaction_nodes finished.
> > 
> > Suggested-by:David Rientjes <rientjes@google.com>
> > Cc:Mel Gorman <mgorman@suse.de>
> > Cc:Andrew Morton <akpm@linux-foundation.org>
> > Cc:Rik van Riel <riel@redhat.com>
> > Cc:Minchan Kim <minchan@kernel.org>
> > Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> > Signed-off-by: Jason Liu <r64343@freescale.com>
> 
> Acked-by: Mel Gorman <mgorman@suse.de>

We have a whole pile of things around there which return
information-free integers.  Should we do this?

--- a/mm/compaction.c~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix
+++ a/mm/compaction.c
@@ -1150,7 +1150,7 @@ unsigned long try_to_compact_pages(struc
 
 
 /* Compact all zones within a node */
-static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
+static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
 {
 	int zoneid;
 	struct zone *zone;
@@ -1183,11 +1183,9 @@ static int __compact_pgdat(pg_data_t *pg
 		VM_BUG_ON(!list_empty(&cc->freepages));
 		VM_BUG_ON(!list_empty(&cc->migratepages));
 	}
-
-	return 0;
 }
 
-int compact_pgdat(pg_data_t *pgdat, int order)
+void compact_pgdat(pg_data_t *pgdat, int order)
 {
 	struct compact_control cc = {
 		.order = order,
@@ -1195,10 +1193,10 @@ int compact_pgdat(pg_data_t *pgdat, int 
 		.page = NULL,
 	};
 
-	return __compact_pgdat(pgdat, &cc);
+	__compact_pgdat(pgdat, &cc);
 }
 
-static int compact_node(int nid)
+static void compact_node(int nid)
 {
 	struct compact_control cc = {
 		.order = -1,
@@ -1206,7 +1204,7 @@ static int compact_node(int nid)
 		.page = NULL,
 	};
 
-	return __compact_pgdat(NODE_DATA(nid), &cc);
+	__compact_pgdat(NODE_DATA(nid), &cc);
 }
 
 /* Compact all nodes in the system */
diff -puN include/linux/compaction.h~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix include/linux/compaction.h
--- a/include/linux/compaction.h~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix
+++ a/include/linux/compaction.h
@@ -23,7 +23,7 @@ extern int fragmentation_index(struct zo
 extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
 			int order, gfp_t gfp_mask, nodemask_t *mask,
 			bool sync, bool *contended, struct page **page);
-extern int compact_pgdat(pg_data_t *pgdat, int order);
+extern void compact_pgdat(pg_data_t *pgdat, int order);
 extern void reset_isolation_suitable(pg_data_t *pgdat);
 extern unsigned long compaction_suitable(struct zone *zone, int order);
 
@@ -80,9 +80,8 @@ static inline unsigned long try_to_compa
 	return COMPACT_CONTINUE;
 }
 
-static inline int compact_pgdat(pg_data_t *pgdat, int order)
+static inline void compact_pgdat(pg_data_t *pgdat, int order)
 {
-	return COMPACT_CONTINUE;
 }
 
 static inline void reset_isolation_suitable(pg_data_t *pgdat)
_


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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[David Rientjes]

On Mon, 7 Jan 2013, Andrew Morton wrote:

> --- a/mm/compaction.c~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix
> +++ a/mm/compaction.c
> @@ -1150,7 +1150,7 @@ unsigned long try_to_compact_pages(struc
>  
>  
>  /* Compact all zones within a node */
> -static int __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
> +static void __compact_pgdat(pg_data_t *pgdat, struct compact_control *cc)
>  {
>  	int zoneid;
>  	struct zone *zone;
> @@ -1183,11 +1183,9 @@ static int __compact_pgdat(pg_data_t *pg
>  		VM_BUG_ON(!list_empty(&cc->freepages));
>  		VM_BUG_ON(!list_empty(&cc->migratepages));
>  	}
> -
> -	return 0;
>  }
>  
> -int compact_pgdat(pg_data_t *pgdat, int order)
> +void compact_pgdat(pg_data_t *pgdat, int order)
>  {
>  	struct compact_control cc = {
>  		.order = order,
> @@ -1195,10 +1193,10 @@ int compact_pgdat(pg_data_t *pgdat, int 
>  		.page = NULL,
>  	};
>  
> -	return __compact_pgdat(pgdat, &cc);
> +	__compact_pgdat(pgdat, &cc);
>  }
>  
> -static int compact_node(int nid)
> +static void compact_node(int nid)
>  {
>  	struct compact_control cc = {
>  		.order = -1,
> @@ -1206,7 +1204,7 @@ static int compact_node(int nid)
>  		.page = NULL,
>  	};
>  
> -	return __compact_pgdat(NODE_DATA(nid), &cc);
> +	__compact_pgdat(NODE_DATA(nid), &cc);
>  }
>  
>  /* Compact all nodes in the system */
> diff -puN include/linux/compaction.h~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix include/linux/compaction.h
> --- a/include/linux/compaction.h~mm-compaction-fix-echo-1-compact_memory-return-error-issue-fix
> +++ a/include/linux/compaction.h
> @@ -23,7 +23,7 @@ extern int fragmentation_index(struct zo
>  extern unsigned long try_to_compact_pages(struct zonelist *zonelist,
>  			int order, gfp_t gfp_mask, nodemask_t *mask,
>  			bool sync, bool *contended, struct page **page);
> -extern int compact_pgdat(pg_data_t *pgdat, int order);
> +extern void compact_pgdat(pg_data_t *pgdat, int order);
>  extern void reset_isolation_suitable(pg_data_t *pgdat);
>  extern unsigned long compaction_suitable(struct zone *zone, int order);
>  
> @@ -80,9 +80,8 @@ static inline unsigned long try_to_compa
>  	return COMPACT_CONTINUE;
>  }
>  
> -static inline int compact_pgdat(pg_data_t *pgdat, int order)
> +static inline void compact_pgdat(pg_data_t *pgdat, int order)
>  {
> -	return COMPACT_CONTINUE;
>  }
>  
>  static inline void reset_isolation_suitable(pg_data_t *pgdat)

Acked-by: David Rientjes <rientjes@google.com>

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Re: [PATCH] mm: compaction: fix echo 1 > compact_memory return error issue

[David Rientjes]

On Sun, 6 Jan 2013, Jason Liu wrote:

> when run the folloing command under shell, it will return error
> sh/$ echo 1 > /proc/sys/vm/compact_memory
> sh/$ sh: write error: Bad address
> 
> After strace, I found the following log:
> ...
> write(1, "1\n", 2)               = 3
> write(1, "", 4294967295)         = -1 EFAULT (Bad address)
> write(2, "echo: write error: Bad address\n", 31echo: write error: Bad address
> ) = 31
> 
> This tells system return 3(COMPACT_COMPLETE) after write data to compact_memory.
> 
> The fix is to make the system just return 0 instead 3(COMPACT_COMPLETE) from
> sysctl_compaction_handler after compaction_nodes finished.
> 
> Suggested-by:David Rientjes <rientjes@google.com>
> Cc:Mel Gorman <mgorman@suse.de>
> Cc:Andrew Morton <akpm@linux-foundation.org>
> Cc:Rik van Riel <riel@redhat.com>
> Cc:Minchan Kim <minchan@kernel.org>
> Cc:KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> Signed-off-by: Jason Liu <r64343@freescale.com>

Acked-by: David Rientjes <rientjes@google.com>

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