[dpdk-dev] [PATCH v5 03/11] eal: introduce memory management wrappers

[Thomas Monjalon]

28/05/2020 13:26, Burakov, Anatoly:
> On 25-May-20 1:37 AM, Dmitry Kozlyuk wrote:
> > +/**
> > + * Memory protection flags.
> > + */
> > +enum rte_mem_prot {
> > +	RTE_PROT_READ = 1 << 0,   /**< Read access. */
> > +	RTE_PROT_WRITE = 1 << 1,  /**< Write access. */
> > +	RTE_PROT_EXECUTE = 1 << 2 /**< Code execution. */
> > +};
> > +
> > +/**
> > + * Additional flags for memory mapping.
> > + */
> > +enum rte_map_flags {
> > +	/** Changes to the mapped memory are visible to other processes. */
> > +	RTE_MAP_SHARED = 1 << 0,
> > +	/** Mapping is not backed by a regular file. */
> > +	RTE_MAP_ANONYMOUS = 1 << 1,
> > +	/** Copy-on-write mapping, changes are invisible to other processes. */
> > +	RTE_MAP_PRIVATE = 1 << 2,
> > +	/**
> > +	 * Force mapping to the requested address. This flag should be used
> > +	 * with caution, because to fulfill the request implementation
> > +	 * may remove all other mappings in the requested region. However,
> > +	 * it is not required to do so, thus mapping with this flag may fail.
> > +	 */
> > +	RTE_MAP_FORCE_ADDRESS = 1 << 3
> > +};
> 
> I have no strong opinion on this, but it feels like the fact that these 
> are enums is a relic from the times where you used enum everywhere :) i 
> have a feeling that DPDK codebase prefers #define's for this usage, 
> while what you have here is more of a C++ thing.

The benefit of using an enum is to explicitly name the type
of the variables, serving documentation purpose.

+1 for the enums