* [RFC PATCH] net, gro: fix the truesize of all fragments
@ 2013-12-20 11:45 Zhi Yong Wu
2013-12-20 13:52 ` Sergei Shtylyov
2013-12-20 14:28 ` Eric Dumazet
0 siblings, 2 replies; 8+ messages in thread
From: Zhi Yong Wu @ 2013-12-20 11:45 UTC (permalink / raw)
To: netdev; +Cc: eric.dumazet, Zhi Yong Wu
From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
When the truesize of all fragments was calculated, it didn't take
the first small piece of data into account.
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
---
net/core/skbuff.c | 10 +++++++---
1 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 2b6b863..0665bd6 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
frag->page_offset += offset;
skb_frag_size_sub(frag, offset);
- /* all fragments truesize : remove (head size + sk_buff) */
+ /**
+ * all fragments truesize :
+ * remove (head size + sk_buff + offset)
+ */
delta_truesize = skb->truesize -
- SKB_TRUESIZE(skb_end_offset(skb));
+ SKB_TRUESIZE(skb_end_offset(skb) + offset);
skb->truesize -= skb->data_len;
skb->len -= skb->data_len;
@@ -3060,7 +3063,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
/* We dont need to clear skbinfo->nr_frags here */
- delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
+ delta_truesize = skb->truesize -
+ SKB_DATA_ALIGN(sizeof(struct sk_buff)) - offset;
NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
goto done;
}
--
1.7.6.5
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 11:45 [RFC PATCH] net, gro: fix the truesize of all fragments Zhi Yong Wu
@ 2013-12-20 13:52 ` Sergei Shtylyov
2013-12-20 13:59 ` Zhi Yong Wu
2013-12-20 14:28 ` Eric Dumazet
1 sibling, 1 reply; 8+ messages in thread
From: Sergei Shtylyov @ 2013-12-20 13:52 UTC (permalink / raw)
To: Zhi Yong Wu, netdev; +Cc: eric.dumazet, Zhi Yong Wu
Hello.
On 20-12-2013 15:45, Zhi Yong Wu wrote:
> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
> When the truesize of all fragments was calculated, it didn't take
> the first small piece of data into account.
> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
> ---
> net/core/skbuff.c | 10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 2b6b863..0665bd6 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
> frag->page_offset += offset;
> skb_frag_size_sub(frag, offset);
>
> - /* all fragments truesize : remove (head size + sk_buff) */
> + /**
Why kernel-doc style comment here? Networking code uses the following
comment style:
/* bla
* bla
*/
> + * all fragments truesize :
> + * remove (head size + sk_buff + offset)
> + */
> delta_truesize = skb->truesize -
> - SKB_TRUESIZE(skb_end_offset(skb));
> + SKB_TRUESIZE(skb_end_offset(skb) + offset);
>
> skb->truesize -= skb->data_len;
> skb->len -= skb->data_len;
WBR, Sergei
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 13:52 ` Sergei Shtylyov
@ 2013-12-20 13:59 ` Zhi Yong Wu
2013-12-20 14:21 ` Sergei Shtylyov
0 siblings, 1 reply; 8+ messages in thread
From: Zhi Yong Wu @ 2013-12-20 13:59 UTC (permalink / raw)
To: Sergei Shtylyov; +Cc: Linux Netdev List, Eric Dumazet, Zhi Yong Wu
On Fri, Dec 20, 2013 at 9:52 PM, Sergei Shtylyov
<sergei.shtylyov@cogentembedded.com> wrote:
> Hello.
>
>
> On 20-12-2013 15:45, Zhi Yong Wu wrote:
>
>> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>
>
>> When the truesize of all fragments was calculated, it didn't take
>> the first small piece of data into account.
>
>
>> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>> ---
>> net/core/skbuff.c | 10 +++++++---
>> 1 files changed, 7 insertions(+), 3 deletions(-)
>
>
>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>> index 2b6b863..0665bd6 100644
>> --- a/net/core/skbuff.c
>> +++ b/net/core/skbuff.c
>> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct
>> sk_buff *skb)
>> frag->page_offset += offset;
>> skb_frag_size_sub(frag, offset);
>>
>> - /* all fragments truesize : remove (head size + sk_buff)
>> */
>> + /**
>
>
> Why kernel-doc style comment here? Networking code uses the following
> comment style:
>
> /* bla
> * bla
> */
No, If you check other comments in networking code, you will see why i
did as that.
/**
* skb_segment - Perform protocol segmentation on skb.
* @skb: buffer to segment
* @features: features for the output path (see dev->features)
*
* This function performs segmentation on the given skb. It returns
* a pointer to the first in a list of new skbs for the segments.
* In case of error it returns ERR_PTR(err).
*/
struct sk_buff *skb_segment
>
>
>> + * all fragments truesize :
>> + * remove (head size + sk_buff + offset)
>> + */
>> delta_truesize = skb->truesize -
>> - SKB_TRUESIZE(skb_end_offset(skb));
>> + SKB_TRUESIZE(skb_end_offset(skb) +
>> offset);
>>
>> skb->truesize -= skb->data_len;
>> skb->len -= skb->data_len;
>
>
> WBR, Sergei
Sorry, what is WBR?
>
--
Regards,
Zhi Yong Wu
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 13:59 ` Zhi Yong Wu
@ 2013-12-20 14:21 ` Sergei Shtylyov
2013-12-20 14:34 ` Zhi Yong Wu
0 siblings, 1 reply; 8+ messages in thread
From: Sergei Shtylyov @ 2013-12-20 14:21 UTC (permalink / raw)
To: Zhi Yong Wu; +Cc: Linux Netdev List, Eric Dumazet, Zhi Yong Wu
Hello.
On 20-12-2013 17:59, Zhi Yong Wu wrote:
>>> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>>> When the truesize of all fragments was calculated, it didn't take
>>> the first small piece of data into account.
>>> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>>> ---
>>> net/core/skbuff.c | 10 +++++++---
>>> 1 files changed, 7 insertions(+), 3 deletions(-)
>>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>>> index 2b6b863..0665bd6 100644
>>> --- a/net/core/skbuff.c
>>> +++ b/net/core/skbuff.c
>>> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct
>>> sk_buff *skb)
>>> frag->page_offset += offset;
>>> skb_frag_size_sub(frag, offset);
>>>
>>> - /* all fragments truesize : remove (head size + sk_buff)
>>> */
>>> + /**
>> Why kernel-doc style comment here? Networking code uses the following
>> comment style:
>> /* bla
>> * bla
>> */
> No, If you check other comments in networking code,
I suggest you do this, and not only comments before functions but also
inside them. I also suggest that you read chapter 8 of Documentation/CodingStyle.
> you will see why i
> did as that.
I repeat, this is kernel-doc style comment, that is used to comment on a
functions/structures, and then can be automatically processed to create kernel
documentation. Your case does not fit for /** comment.
> /**
> * skb_segment - Perform protocol segmentation on skb.
> * @skb: buffer to segment
> * @features: features for the output path (see dev->features)
> *
> * This function performs segmentation on the given skb. It returns
> * a pointer to the first in a list of new skbs for the segments.
> * In case of error it returns ERR_PTR(err).
> */
> struct sk_buff *skb_segment
>>> + * all fragments truesize :
>>> + * remove (head size + sk_buff + offset)
>>> + */
>>> delta_truesize = skb->truesize -
>>> - SKB_TRUESIZE(skb_end_offset(skb));
>>> + SKB_TRUESIZE(skb_end_offset(skb) +
>>> offset);
>>>
>>> skb->truesize -= skb->data_len;
>>> skb->len -= skb->data_len;
>>
>>
>> WBR, Sergei
> Sorry, what is WBR?
With best regards. Nothing offensive. :-)
WBR, Sergei
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 14:21 ` Sergei Shtylyov
@ 2013-12-20 14:34 ` Zhi Yong Wu
0 siblings, 0 replies; 8+ messages in thread
From: Zhi Yong Wu @ 2013-12-20 14:34 UTC (permalink / raw)
To: Sergei Shtylyov; +Cc: Linux Netdev List, Eric Dumazet, Zhi Yong Wu
On Fri, Dec 20, 2013 at 10:21 PM, Sergei Shtylyov
<sergei.shtylyov@cogentembedded.com> wrote:
> Hello.
>
>
> On 20-12-2013 17:59, Zhi Yong Wu wrote:
>
>>>> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>
>
>>>> When the truesize of all fragments was calculated, it didn't take
>>>> the first small piece of data into account.
>
>
>>>> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>>>> ---
>>>> net/core/skbuff.c | 10 +++++++---
>>>> 1 files changed, 7 insertions(+), 3 deletions(-)
>
>
>>>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>>>> index 2b6b863..0665bd6 100644
>>>> --- a/net/core/skbuff.c
>>>> +++ b/net/core/skbuff.c
>>>> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct
>>>> sk_buff *skb)
>>>> frag->page_offset += offset;
>>>> skb_frag_size_sub(frag, offset);
>>>>
>>>> - /* all fragments truesize : remove (head size + sk_buff)
>>>> */
>>>> + /**
>
>
>>> Why kernel-doc style comment here? Networking code uses the following
>>> comment style:
>
>
>>> /* bla
>>> * bla
>>> */
>
>
>> No, If you check other comments in networking code,
>
>
> I suggest you do this, and not only comments before functions but also
> inside them. I also suggest that you read chapter 8 of
> Documentation/CodingStyle.
>
>
>> you will see why i
>> did as that.
>
>
> I repeat, this is kernel-doc style comment, that is used to comment on a
> functions/structures, and then can be automatically processed to create
> kernel documentation. Your case does not fit for /** comment.
Your explanation is very clear, i accept your advice, thanks.
>
>
>> /**
>> * skb_segment - Perform protocol segmentation on skb.
>> * @skb: buffer to segment
>> * @features: features for the output path (see dev->features)
>> *
>> * This function performs segmentation on the given skb. It returns
>> * a pointer to the first in a list of new skbs for the segments.
>> * In case of error it returns ERR_PTR(err).
>> */
>> struct sk_buff *skb_segment
>
>
>>>> + * all fragments truesize :
>>>> + * remove (head size + sk_buff + offset)
>>>> + */
>>>> delta_truesize = skb->truesize -
>>>> - SKB_TRUESIZE(skb_end_offset(skb));
>>>> + SKB_TRUESIZE(skb_end_offset(skb) +
>>>> offset);
>>>>
>>>> skb->truesize -= skb->data_len;
>>>> skb->len -= skb->data_len;
>>>
>>>
>>>
>>> WBR, Sergei
>
>
>> Sorry, what is WBR?
>
>
> With best regards. Nothing offensive. :-)
>
> WBR, Sergei
>
--
Regards,
Zhi Yong Wu
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 11:45 [RFC PATCH] net, gro: fix the truesize of all fragments Zhi Yong Wu
2013-12-20 13:52 ` Sergei Shtylyov
@ 2013-12-20 14:28 ` Eric Dumazet
2013-12-20 14:37 ` Zhi Yong Wu
1 sibling, 1 reply; 8+ messages in thread
From: Eric Dumazet @ 2013-12-20 14:28 UTC (permalink / raw)
To: Zhi Yong Wu; +Cc: netdev, Zhi Yong Wu
On Fri, 2013-12-20 at 19:45 +0800, Zhi Yong Wu wrote:
> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>
> When the truesize of all fragments was calculated, it didn't take
> the first small piece of data into account.
>
> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
> ---
> net/core/skbuff.c | 10 +++++++---
> 1 files changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 2b6b863..0665bd6 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
> frag->page_offset += offset;
> skb_frag_size_sub(frag, offset);
>
> - /* all fragments truesize : remove (head size + sk_buff) */
> + /**
> + * all fragments truesize :
> + * remove (head size + sk_buff + offset)
> + */
> delta_truesize = skb->truesize -
> - SKB_TRUESIZE(skb_end_offset(skb));
> + SKB_TRUESIZE(skb_end_offset(skb) + offset);
>
> skb->truesize -= skb->data_len;
> skb->len -= skb->data_len;
> @@ -3060,7 +3063,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
> memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
> /* We dont need to clear skbinfo->nr_frags here */
>
> - delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
> + delta_truesize = skb->truesize -
> + SKB_DATA_ALIGN(sizeof(struct sk_buff)) - offset;
> NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
> goto done;
> }
Nope, this patch is not needed.
truesize is about tracking the memory we allocated, not the memory we
really use.
What exact issue do you have ? I suspect a bug in a driver.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 14:28 ` Eric Dumazet
@ 2013-12-20 14:37 ` Zhi Yong Wu
2013-12-20 14:42 ` Eric Dumazet
0 siblings, 1 reply; 8+ messages in thread
From: Zhi Yong Wu @ 2013-12-20 14:37 UTC (permalink / raw)
To: Eric Dumazet; +Cc: Linux Netdev List, Zhi Yong Wu
On Fri, Dec 20, 2013 at 10:28 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Fri, 2013-12-20 at 19:45 +0800, Zhi Yong Wu wrote:
>> From: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>>
>> When the truesize of all fragments was calculated, it didn't take
>> the first small piece of data into account.
>>
>> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>> ---
>> net/core/skbuff.c | 10 +++++++---
>> 1 files changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
>> index 2b6b863..0665bd6 100644
>> --- a/net/core/skbuff.c
>> +++ b/net/core/skbuff.c
>> @@ -3027,9 +3027,12 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
>> frag->page_offset += offset;
>> skb_frag_size_sub(frag, offset);
>>
>> - /* all fragments truesize : remove (head size + sk_buff) */
>> + /**
>> + * all fragments truesize :
>> + * remove (head size + sk_buff + offset)
>> + */
>> delta_truesize = skb->truesize -
>> - SKB_TRUESIZE(skb_end_offset(skb));
>> + SKB_TRUESIZE(skb_end_offset(skb) + offset);
>>
>> skb->truesize -= skb->data_len;
>> skb->len -= skb->data_len;
>> @@ -3060,7 +3063,8 @@ int skb_gro_receive(struct sk_buff **head, struct sk_buff *skb)
>> memcpy(frag + 1, skbinfo->frags, sizeof(*frag) * skbinfo->nr_frags);
>> /* We dont need to clear skbinfo->nr_frags here */
>>
>> - delta_truesize = skb->truesize - SKB_DATA_ALIGN(sizeof(struct sk_buff));
>> + delta_truesize = skb->truesize -
>> + SKB_DATA_ALIGN(sizeof(struct sk_buff)) - offset;
>> NAPI_GRO_CB(skb)->free = NAPI_GRO_FREE_STOLEN_HEAD;
>> goto done;
>> }
>
>
> Nope, this patch is not needed.
>
> truesize is about tracking the memory we allocated, not the memory we
> really use.
wow, i forgot this, thanks for yor reminder.
>
> What exact issue do you have ? I suspect a bug in a driver.
I didn't hit any issue, but found this when i read gro related code. a
but in a driver? sorry, i don't know, look forward to seeing your fix.
>
>
>
--
Regards,
Zhi Yong Wu
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [RFC PATCH] net, gro: fix the truesize of all fragments
2013-12-20 14:37 ` Zhi Yong Wu
@ 2013-12-20 14:42 ` Eric Dumazet
0 siblings, 0 replies; 8+ messages in thread
From: Eric Dumazet @ 2013-12-20 14:42 UTC (permalink / raw)
To: Zhi Yong Wu; +Cc: Linux Netdev List, Zhi Yong Wu
On Fri, 2013-12-20 at 22:37 +0800, Zhi Yong Wu wrote:
> On Fri, Dec 20, 2013 at 10:28 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> > Nope, this patch is not needed.
> >
> > truesize is about tracking the memory we allocated, not the memory we
> > really use.
> wow, i forgot this, thanks for yor reminder.
> >
> > What exact issue do you have ? I suspect a bug in a driver.
> I didn't hit any issue, but found this when i read gro related code. a
> but in a driver? sorry, i don't know, look forward to seeing your fix.
No, I have no particular issue with this code, I thought you had a
problem on a running machine.
If you found this by code review, then everything is fine, and
no patch is needed at this point.
Thanks
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2013-12-20 14:42 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
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2013-12-20 11:45 [RFC PATCH] net, gro: fix the truesize of all fragments Zhi Yong Wu
2013-12-20 13:52 ` Sergei Shtylyov
2013-12-20 13:59 ` Zhi Yong Wu
2013-12-20 14:21 ` Sergei Shtylyov
2013-12-20 14:34 ` Zhi Yong Wu
2013-12-20 14:28 ` Eric Dumazet
2013-12-20 14:37 ` Zhi Yong Wu
2013-12-20 14:42 ` Eric Dumazet
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