# Re: \[RFC 01/19\] staging: qlge: fix incorrect truesize accounting

- From: Coiby Xu \<hidden\>
- Date: 2021-06-22 11:40:36 
- List: netdev
- Page: https://ratatoskr.run/netdev/2021/06/1422359
- Thread: https://ratatoskr.run/linux-staging/2021/06/11205922/t.md

```text
On Mon, Jun 21, 2021 at 05:10:27PM +0300, Dan Carpenter wrote:
>On Mon, Jun 21, 2021 at 09:48:44PM +0800, Coiby Xu wrote:
>> Commit 7c734359d3504c869132166d159c7f0649f0ab34 ("qlge: Size RX buffers
>> based on MTU") introduced page_chunk structure. We should add
>> qdev->lbq_buf_size to skb->truesize after __skb_fill_page_desc.
>>
>
>Add a Fixes tag.

I will fix it in next version, thanks!

>
>The runtime impact of this is just that ethtool will report things
>incorrectly, right?  It's not 100% from the commit message.  Could you
>please edit the commit message so that an ignoramous like myself can
>understand it?

I'm not sure how it would affect ethtool. But according to "git log
--grep=truesize", it affects coalescing SKBs. Btw, I fixed the issue
according to the definition of truesize which according to Linux Kernel
Network by Rami Rosen, it's defined as follows,
> The total memory allocated for the SKB (including the SKB structure itself and the size of the allocated data block).

I'll edit the commit message to include it, thanks!

>
>Why is this an RFC instead of just a normal patch which we can apply?

After doing the tests mentioned in the cover letter, I found Red Hat's network QE team has quite a rigorous test suite. But I needed to return the machine before having the time to learn about the test suite and run it by myself. So I mark it as an RFC before I borrow the machine again to run the test suite.

>
>regards,
>dan carpenter
>

-- 
Best regards,
Coiby
```