
Linux makes a habit of writing the same value to the SCTLR that it already holds. In a sample boot of the kernel to a shell prompt it wrote the SCTLR with the value it already held 325465 times, and wrote different values just 3 times. Skip flushing the TLB if the SCTLR value isn't actually being changed; this speeds up my sample boot by 3-5%. Reported-by: Laurent Desnogues <laurent.desnogues@gmail.com> Reviewed-by: Laurent Desnogues <laurent.desnogues@gmail.com> Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1399560029-19007-1-git-send-email-peter.maydell@linaro.org