[PATCH]bisected:fs:anon_inodes.c one processor core reads full throttle.

[PATCH]bisected:fs:anon_inodes.c one processor core reads full throttle.

[Justin P. Mattock]

I have no idea why this is doing this., but when doing
watch cat /proc/cpuinfo I see one of my cores reading 
full throttle.

The bisect results are this:

a7cf4145bb86aaf85d4d4d29a69b50b688e2e49d is the first bad commit
commit a7cf4145bb86aaf85d4d4d29a69b50b688e2e49d
Author: Eric Paris <eparis@redhat.com>
Date:   Fri May 14 11:44:10 2010 -0400

    anon_inode: set S_IFREG on the anon_inode
    
    anon_inode_mkinode() sets inode->i_mode = S_IRUSR | S_IWUSR;  This means
    that (inode->i_mode & S_IFMT) == 0.  This trips up some SELinux code that
    needs to determine if a given inode is a regular file, a directory, etc.
    The easiest solution is to just make sure that the anon_inode also sets
    S_IFREG.
    
    Signed-off-by: Eric Paris <eparis@redhat.com>
    Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>


doing a git revert a7cf4145 gets cpuinfo to show both cores
running as they should.(both iMac, and macbookpro hit this).

I looked at the manual for fstat, and am not understanding
how  S_IFREG(standard file) can cause such and issue.
Below(after reading the man), was the only other option
I can make out(other than FIFO)to use to fix this issue.

either using S_IFMT is a good solution, or it's not
(I'm not sure at the moment),let me know. 


 
 Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>

---
 fs/anon_inodes.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 9bd4b38..8ac1693 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -205,7 +205,7 @@ static struct inode *anon_inode_mkinode(void)
 	 * that it already _is_ on the dirty list.
 	 */
 	inode->i_state = I_DIRTY;
-	inode->i_mode = S_IFREG | S_IRUSR | S_IWUSR;
+	inode->i_mode = S_IFMT | S_IRUSR | S_IWUSR;
 	inode->i_uid = current_fsuid();
 	inode->i_gid = current_fsgid();
 	inode->i_flags |= S_PRIVATE;
-- 
1.6.5.GIT

Re: [PATCH]bisected:fs:anon_inodes.c one processor core reads full throttle.

[Eric Paris]

On Mon, 2010-05-24 at 19:54 -0700, Justin P. Mattock wrote:
> I have no idea why this is doing this., but when doing
> watch cat /proc/cpuinfo I see one of my cores reading 
> full throttle.

Check out:
http://lkml.org/lkml/2010/5/22/150
and
http://lkml.org/lkml/2010/5/25/159

Sorry, but this patch isn't right (S_IFMNT shouldn't be used like that)

-Eric

Re: [PATCH]bisected:fs:anon_inodes.c one processor core reads full throttle.

[Justin P. Mattock]

On 05/25/2010 06:53 AM, Eric Paris wrote:
> On Mon, 2010-05-24 at 19:54 -0700, Justin P. Mattock wrote:
>    
>> I have no idea why this is doing this., but when doing
>> watch cat /proc/cpuinfo I see one of my cores reading
>> full throttle.
>>      
> Check out:
> http://lkml.org/lkml/2010/5/22/150
> and
> http://lkml.org/lkml/2010/5/25/159
>
> Sorry, but this patch isn't right (S_IFMNT shouldn't be used like that)
>
> -Eric
>
>
>    
ahh.. so udev is getting crapped out..
alright I'll revert this for now..

Justin P. Mattock