Hi Ilpo, On 11/20/2023 3:13 AM, Ilpo Järvinen wrote: > The fill_buf code prevents compiler optimizating the entire read loop > away by writing the final value of the variable into a file. While it > achieves the goal, writing into a file requires significant amount of > work within the innermost test loop and also error handling. > > A simpler approach is to take advantage of volatile. Writing to a > variable through a volatile pointer is enough to prevent compiler from > optimizing the write away, and therefore compiler cannot remove the > read loop either. > > Add a volatile 'value_sink' into resctrl_tests.c and make fill_buf to > write into it. As a result, the error handling in fill_buf.c can be > simplified. > The subject and changelog describes the need for a volatile variable. The patch introduces two volatile variables. Could you please elaborate why two volatile variables are needed? Reinette
