Subject: Re: [PATCH net-next] net: hns: optimize XGE capability by reducing cpu usage

From: Joe Perches <[email-masked]>
Date: Mon, 07 Dec 2015 01:05:09 -0800

On Mon, 2015-12-07 at 16:58 +0800, Yankejian (Hackim Yim) wrote:
> On 2015/12/7 11:32, Joe Perches wrote:
> > On Sun, 2015-12-06 at 22:29 -0500, David Miller wrote:
> > > > From: yankejian <[email-masked]>
> > > > Date: Sat, 5 Dec 2015 15:32:29 +0800
> > > > 
> > > > > > +#if (PAGE_SIZE < 8192)
> > > > > > +     if (hnae_buf_size(ring) == HNS_BUFFER_SIZE_2048) {
> > > > > > +             truesize = hnae_buf_size(ring);
> > > > > > +     } else {
> > > > > > +             truesize = ALIGN(size, L1_CACHE_BYTES);
> > > > > > +             last_offset = hnae_page_size(ring) - hnae_buf_size(ring);
> > > > > > +     }
> > > > > > +
> > > > > > +#else
> > > > > > +             truesize = ALIGN(size, L1_CACHE_BYTES);
> > > > > > +             last_offset = hnae_page_size(ring) - hnae_buf_size(ring);
> > > > > > +#endif
> > > > 
> > > > This is not indented properly, and it looks terrible.
> > And it makes one curious as to why last_offset isn't set
> > in the first block.
> 
> Hi Joe,

Hello.

> if hnae_buf_size que equal to HNS_BUFFER_SIZE, last_offset is useless in the routines of this function.
> so it is ignored in the first block. thanks for your suggestion.

More to the point, last_offset is initialized to 0.

It'd be clearer not to initialize it at all and
set it to 0 in the first block and not overwrite
the initialization in each subsequent block.