Patchwork Badness with the kernel version 2.6.35-rc1-git1 running on P6 box

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Submitter Eric Dumazet
Date July 16, 2010, 12:20 p.m.
Message ID <1279282842.2549.16.camel@edumazet-laptop>
Download mbox | patch
Permalink /patch/59095/
State Not Applicable
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Eric Dumazet - July 16, 2010, 12:20 p.m.
Le vendredi 16 juillet 2010 à 11:56 +0200, Eric Dumazet a écrit :

> [PATCH] ehea: ehea_get_stats() should use GFP_KERNEL
> 
> ehea_get_stats() is called in process context and should use GFP_KERNEL
> allocation instead of GFP_ATOMIC.
> 
> Clearing stats at beginning of ehea_get_stats() is racy in case of
> concurrent stat readers.
> 
> get_stats() can also use netdev net_device_stats, instead of a private
> copy.
> 
> Reported-by: divya <dipraksh@linux.vnet.ibm.com>
> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
> ---
>  drivers/net/ehea/ehea.h      |    1 -
>  drivers/net/ehea/ehea_main.c |    6 ++----
>  2 files changed, 2 insertions(+), 5 deletions(-)
> 
> 

Hmm, net-next-2.6 contains following patch :

commit 3d8009c780ee90fccb5c171caf30aff839f13547
Author: Brian King <brking@linux.vnet.ibm.com>
Date:   Wed Jun 30 11:59:12 2010 +0000

    ehea: Allocate stats buffer with GFP_KERNEL
    
    Since ehea_get_stats calls ehea_h_query_ehea_port, which
    can sleep, we can also sleep when allocating a page in
    this function. This fixes some memory allocation failure
    warnings seen under low memory conditions.
    
    Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

                goto out;
David Miller - July 18, 2010, 9:51 p.m.
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 16 Jul 2010 14:20:42 +0200

> Le vendredi 16 juillet 2010 à 11:56 +0200, Eric Dumazet a écrit :
> 
>> [PATCH] ehea: ehea_get_stats() should use GFP_KERNEL
>> 
>> ehea_get_stats() is called in process context and should use GFP_KERNEL
>> allocation instead of GFP_ATOMIC.
>> 
>> Clearing stats at beginning of ehea_get_stats() is racy in case of
>> concurrent stat readers.
>> 
>> get_stats() can also use netdev net_device_stats, instead of a private
>> copy.
>> 
>> Reported-by: divya <dipraksh@linux.vnet.ibm.com>
>> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
>> ---
>>  drivers/net/ehea/ehea.h      |    1 -
>>  drivers/net/ehea/ehea_main.c |    6 ++----
>>  2 files changed, 2 insertions(+), 5 deletions(-)
>> 
>> 
> 
> Hmm, net-next-2.6 contains following patch :

If people think ehea usage is ubiquitous enough to deserve a backport
of this to net-2.6, fine.  But personally I don't think it's worth it.

Can someone close the kernel bugzilla 16406 created for this bug?  This
patch we have already obviously would fix this issue.

Patch

diff --git a/drivers/net/ehea/ehea_main.c b/drivers/net/ehea/ehea_main.c
index 8b92acb..3beba70 100644
--- a/drivers/net/ehea/ehea_main.c
+++ b/drivers/net/ehea/ehea_main.c
@@ -335,7 +335,7 @@  static struct net_device_stats
*ehea_get_stats(struct net_device *dev)
 
        memset(stats, 0, sizeof(*stats));
 
-       cb2 = (void *)get_zeroed_page(GFP_ATOMIC);
+       cb2 = (void *)get_zeroed_page(GFP_KERNEL);
        if (!cb2) {
                ehea_error("no mem for cb2");