On 10/12/2015 16:59, Matan Barak wrote: > On Mon, Dec 7, 2015 at 3:18 PM, Haggai Eran <[email protected]> wrote: >> On 12/03/2015 05:44 PM, Matan Barak wrote: >>> Extending core and vendor verb commands require us to check that the >>> unknown part of the user's given command is all zeros. >>> Adding ib_is_udata_cleared in order to do so. >>> >> >> Why not copy the data into kernel space and run memchr_inv() on it? >> > > Probably less efficient, isn't it? Why do you think it is less efficient?
I'm not sure calling copy_from_user multiple times is very efficient. For once, you are calling access_ok multiple times. I guess it depends on the amount of data you are copying. > I know it isn't data path, but we'll execute this code in all extended > functions (sometimes even more than once). Do you think it is important enough to maintain our own copy of memchr_inv()? -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
