Re: [PLEASE-TESTME] Zerocopy networking patch, 2.4.0-1

[Albert D. Cahalan]

>> struct kiovec2 {
>> 	int             nbufs;          /* Kiobufs actually referenced */
>> 	int             array_len;      /* Space in the allocated lists */
>> 	struct kiobuf * bufs;
>
> Any reason for array_len?
>
> Why not just 
> 
> 	int nbufs,
> 	struct kiobuf *bufs;
>
> Remember: simplicity is a virtue. 
>
> Simplicity is also what makes it usable for people who do NOT want to have
> huge overhead.
>
>> 	unsigned int    locked : 1;     /* If set, pages has been locked */
>
> Remove this. I don't think it's valid to lock the pages. Who wants to use
> this anyway?
>
>> 	/* Always embed enough struct pages for 64k of IO */
>> 	struct kiobuf * buf_array[KIO_STATIC_PAGES];	 
>
> Kill kill kill kill. 
>
> If somebody wants to embed a kiovec into their own data structure, THEY
> can decide to add their own buffers etc. A fundamental data structure
> should _never_ make assumptions like this.

What about getting rid of both that and the pointer, and just
hanging that data on the end as a variable length array?

struct kiovec2{
  int nbufs;
  /* ... */
  struct kiobuf[0];
}