On Fri, 2017-06-02 at 21:43:30 UTC, Breno Leitao wrote: > Currently tsk->thread->load_vec and load_fp are not initialized during a > task creation, which set garbage to these variables (non-zero value). > > These variables will be checked later at restore_math() to validate if the > FP and vectors are being utilized. Since these values might be non-zero, > the restore_math() will continue to save the FP and vectors even if they > were never utilized before the userspace application. load_fp and load_vec > counters will then overflow and the FP and Altivec will be finally > disabled, but before that condition is reached (counter overflow) several > context switches restored FP and vector registers without need, causing a > performance degradation. > > Signed-off-by: Breno Leitao <[email protected]> > Signed-off-by: Gustavo Romero <[email protected]> > Acked-by: Anton Blanchard <[email protected]>
Applied to powerpc fixes, thanks. https://git.kernel.org/powerpc/c/1195892c091a15cc862f4e202482a3 cheers
