[PATCH] x86, mce: cleanup initcall of debugfs for mce

[PATCH] x86, mce: cleanup initcall of debugfs for mce

[Jin Dongming]

(Send this patch again because I posted the patch as an attachment.

This patch is made based on the v5 patches of Huangying for mce.
Before using this patch, please apply the patches of Huangying.
The patches' URLs of Huangying are listed as following:
1.x86: MCE: Support specifying context for software mce injection
  URL: http://marc.info/?l=linux-kernel&m=124900459100786&w=2
2.x86: MCE: Support specifying raise mode for software MCE injection
  URL: http://marc.info/?l=linux-kernel&m=124900459100795&w=2
3.x86: MCE: Move debugfs mce dir creating to mce.c
  URL: http://marc.info/?l=linux-kernel&m=124900459100790&w=2
4.x86: MCE: Fake panic support for MCE testing
  URL: http://marc.info/?l=linux-kernel&m=124900453800724&w=2

There are two initcall functions in the patches of Huangying,
mce_debugfs_init() used in mce.c and severities_debugfs_init() used
in mce-severity.c. I think an initcall function is enough for mce
debug. So we make them into one initcall function.

This version is based x86-tip/mce.

Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
 arch/x86/kernel/cpu/mcheck/mce-internal.h |    2 +-
 arch/x86/kernel/cpu/mcheck/mce-severity.c |   13 +++----------
 arch/x86/kernel/cpu/mcheck/mce.c          |   24 +++++++++++-------------
 3 files changed, 15 insertions(+), 24 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h
b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 32996f9..ca8421d 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -22,7 +22,7 @@ struct mce_bank {
 };

 int mce_severity(struct mce *a, int tolerant, char **msg);
-struct dentry *mce_get_debugfs_dir(void);
+int __init severities_debugfs_init(struct dentry *dmce);

 extern int mce_ser;

diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c
b/arch/x86/kernel/cpu/mcheck/mce-severity.c
index bc35a07..49e57ab 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-severity.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c
@@ -193,22 +193,15 @@ static const struct file_operations
severities_coverage_fops = {
 	.write		= severities_coverage_write,
 };

-static int __init severities_debugfs_init(void)
+int __init severities_debugfs_init(struct dentry *dmce)
 {
-	struct dentry *dmce = NULL, *fseverities_coverage = NULL;
+	struct dentry *fseverities_coverage = NULL;

-	dmce = mce_get_debugfs_dir();
-	if (dmce == NULL)
-		goto err_out;
 	fseverities_coverage = debugfs_create_file("severities-coverage",
 						   0444, dmce, NULL,
 						   &severities_coverage_fops);
 	if (fseverities_coverage == NULL)
-		goto err_out;
+		return -ENOMEM;

 	return 0;
-
-err_out:
-	return -ENOMEM;
 }
-late_initcall(severities_debugfs_init);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 54bd1b2..37b6526 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2018,16 +2018,6 @@ static int __init mcheck_disable(char *str)
 __setup("nomce", mcheck_disable);

 #ifdef CONFIG_DEBUG_FS
-struct dentry *mce_get_debugfs_dir(void)
-{
-	static struct dentry *dmce;
-
-	if (!dmce)
-		dmce = debugfs_create_dir("mce", NULL);
-
-	return dmce;
-}
-
 static void mce_reset(void)
 {
 	cpu_missing = 0;
@@ -2055,17 +2045,25 @@ DEFINE_SIMPLE_ATTRIBUTE(fake_panic_fops, fake_panic_get,

 static int __init mce_debugfs_init(void)
 {
-	struct dentry *dmce, *ffake_panic;
+	struct dentry *dmce = NULL, *ffake_panic = NULL;

-	dmce = mce_get_debugfs_dir();
+	dmce = debugfs_create_dir("mce", NULL);
 	if (!dmce)
 		return -ENOMEM;
 	ffake_panic = debugfs_create_file("fake_panic", 0444, dmce, NULL,
 					  &fake_panic_fops);
 	if (!ffake_panic)
-		return -ENOMEM;
+		goto err_out;
+
+	if (severities_debugfs_init(dmce))
+		goto err_out;

 	return 0;
+
+err_out:
+	debugfs_remove_recursive(dmce);
+
+	return -ENOMEM;
 }
 late_initcall(mce_debugfs_init);
 #endif
-- 
1.6.2.2

Re: [PATCH] x86, mce: cleanup initcall of debugfs for mce

[Andi Kleen]

>  int mce_severity(struct mce *a, int tolerant, char **msg);
> -struct dentry *mce_get_debugfs_dir(void);
> +int __init severities_debugfs_init(struct dentry *dmce);

__init is not needed on prototypes.

Sorry but I think it's better to have an own initcall per file,
that makes everything more self contained and easier to read.

-Andi

Re: [PATCH] x86, mce: cleanup initcall of debugfs for mce

[Jin Dongming]

Andi Kleen wrote:
> 
> Sorry but I think it's better to have an own initcall per file,
> that makes everything more self contained and easier to read.
> 
> -Andi
> 
Thank you for your comment.

That's OK, but this patch is also used for resolving compile error
without CONFIG_DEBUG_FS.  Then how about this patch?

Best regards,
Jin Dongming


===

[PATCH] x86,mce: Add ifdef for severities_debugfs_init()

This patch is made based on the v5 patches of Huangying for mce.
Before using this patch, please apply the patches of Huangying.
The patches' URLs of Huangying are listed as following:
1.x86: MCE: Support specifying context for software mce injection
  URL: http://marc.info/?l=linux-kernel&m=124900459100786&w=2
2.x86: MCE: Support specifying raise mode for software MCE injection
  URL: http://marc.info/?l=linux-kernel&m=124900459100795&w=2
3.x86: MCE: Move debugfs mce dir creating to mce.c
  URL: http://marc.info/?l=linux-kernel&m=124900459100790&w=2
4.x86: MCE: Fake panic support for MCE testing
  URL: http://marc.info/?l=linux-kernel&m=124900453800724&w=2

When the kernel is compiled without CONFIG_DEBUG_FS, compiler could
not find out mce_get_debugfs_dir() which is used by
severities_debugfs_init() and output the error message.

This version is based x86-tip/mce.

Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com>
Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
---
 arch/x86/kernel/cpu/mcheck/mce-internal.h |    3 +++
 arch/x86/kernel/cpu/mcheck/mce-severity.c |    2 ++
 2 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 32996f9..58b01d4 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -22,7 +22,10 @@ struct mce_bank {
 };
 
 int mce_severity(struct mce *a, int tolerant, char **msg);
+
+#ifdef CONFIG_DEBUG_FS
 struct dentry *mce_get_debugfs_dir(void);
+#endif
 
 extern int mce_ser;
 
diff --git a/arch/x86/kernel/cpu/mcheck/mce-severity.c b/arch/x86/kernel/cpu/mcheck/mce-severity.c
index bc35a07..8a85dd1 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-severity.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c
@@ -139,6 +139,7 @@ int mce_severity(struct mce *a, int tolerant, char **msg)
 	}
 }
 
+#ifdef CONFIG_DEBUG_FS
 static void *s_start(struct seq_file *f, loff_t *pos)
 {
 	if (*pos >= ARRAY_SIZE(severities))
@@ -212,3 +213,4 @@ err_out:
 	return -ENOMEM;
 }
 late_initcall(severities_debugfs_init);
+#endif
-- 
1.6.2.2

Re: [PATCH] x86, mce: cleanup initcall of debugfs for mce

[Andi Kleen]

Jin Dongming wrote:
> Andi Kleen wrote:
>> Sorry but I think it's better to have an own initcall per file,
>> that makes everything more self contained and easier to read.
>>
>> -Andi
>>
> Thank you for your comment.
> 
> That's OK, but this patch is also used for resolving compile error
> without CONFIG_DEBUG_FS.  Then how about this patch?


Compiler errors should be always fixed of course. But did you check
the compile error is still in the latest version of the x86/mce branch
of
git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip.git
It might be fixed already.

-Andi

Re: [PATCH] x86, mce: cleanup initcall of debugfs for mce

[Hidetoshi Seto]

Andi Kleen wrote:
> Jin Dongming wrote:
>> Andi Kleen wrote:
>>> Sorry but I think it's better to have an own initcall per file,
>>> that makes everything more self contained and easier to read.
>>>
>>> -Andi
>>>
>> Thank you for your comment.
>>
>> That's OK, but this patch is also used for resolving compile error
>> without CONFIG_DEBUG_FS.  Then how about this patch?
> 
> 
> Compiler errors should be always fixed of course. But did you check
> the compile error is still in the latest version of the x86/mce branch
> of
> git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip.git
> It might be fixed already.

The compiler error pointed by Jin will be introduced by Huang's patch:
 3.x86: MCE: Move debugfs mce dir creating to mce.c
   URL: http://marc.info/?l=linux-kernel&m=124900459100790&w=2
and it seems that none of tip branches have Huang's debug patch set yet.
At least I could not find them in today's tip/x86/mce and tip/master.
(Or I might have trouble on syncing of git.)

I think that the previous change to unify initcalls is worth to be in
an incremental patch, but this trivial change to add ifdef could be
done by updating original patch if you'd like to do so.


Thanks,
H.Seto