Re: [dpdk-dev] [PATCH v4 0/9] Improve cast alignment for strict aligned machines

[Thomas Monjalon <thomas.monjalon@6wind.com>]

2015-06-23 17:36, Olivier MATZ:
> On 06/22/2015 08:34 PM, Cyril Chemparathy wrote:
> > This series contains a few improvements that allow the DPDK code base
> > to build properly on machines that enforce strict pointer cast
> > alignment constraints.
> >
> > When dealing with packet data which could be arbitrarily aligned, we
> > get the compiler to do the right thing by (a) making sure that header
> > types are packed, and (b) introducing and using
> > unaligned_uint(16|32|64)_t types when upcasting from byte pointers.
> >
> > In a few other instances, we know apriori that the pointer cast cannot
> > possibly break alignment.  This applies to the changes in mempool,
> > hash, mbuf, and the ethdev stats code.  Here, we simply silence the
> > compiler by casting through (void *) using the RTE_PTR_(ADD|SUB)
> > macros.
> >
> > Finally, we introduce a new rte_pktmbuf_mtod_offset() helper to return
> > a type casted pointer to an offset within the packet data.  This
> > replaces the following commonly used pattern:
> > 	(struct foo *)(rte_pktmbuf_mtod(m, char *) + offset)
> > with:
> > 	rte_pktmbuf_mtod_offset(m, struct foo *, offset)
> >
> > To ensure consistency, the above transform was applied throughout the
> > code base using the coccinelle semantic patching tool.
> 
> Series
> Acked-by: Olivier Matz <olivier.matz@6wind.com>

Applied, thanks