On Mon, Oct 07, 2019 at 03:22:30PM -0700, Bart Van Assche wrote: > On 10/7/19 9:03 AM, Leon Romanovsky wrote: > > On Mon, Oct 07, 2019 at 08:07:55AM -0700, Bart Van Assche wrote: > > > On 10/7/19 6:59 AM, Leon Romanovsky wrote: > > > > /* > > > > - * Check if the device might use memory registration. This is > > > > currently only > > > > - * true for iWarp devices. In the future we can hopefully fine tune > > > > this based > > > > - * on HCA driver input. > > > > + * Check if the device might use memory registration. This is currently > > > > + * true for iWarp devices and devices that have optimized SGL > > > > registration > > > > + * logic. > > > > */ > > > > > > The following sentence in the above comment looks confusing to me: "Check > > > if > > > the device might use memory registration." That sentence suggests that the > > > HCA decides whether or not to use memory registration. Isn't it the RDMA > > > R/W > > > code that decides whether or not to use memory registration? > > > > I'm open for any reasonable text, what do you expect to be written there? > > Hi Leon, > > How about the following (not sure whether this is correct)? > > /* > * Report whether memory registration should be used. Memory > * registration must be used for iWarp devices because of > * iWARP-specific limitations. Memory registration is also enabled if > * registering memory will yield better performance than using multiple > * SGE entries. > */
"Better performance" is relevant for mlx5 only, maybe others will use this max_.. field to overcome their HW limitations. Thanks > > Thanks, > > Bart.
