[PATCH v2 01/25] powerpc/8xx: Save r3 all the time in DTLB miss handler

Scott Wood scottwood at freescale.com
Tue Sep 29 08:07:17 AEST 2015

On Tue, Sep 22, 2015 at 06:50:29PM +0200, Christophe Leroy wrote:
> We are spending between 40 and 160 cycles with a mean of 65 cycles in
> the TLB handling routines (measured with mftbl) so make it more
> simple althought it adds one instruction.
> Signed-off-by: Christophe Leroy <christophe.leroy at c-s.fr>

Does this just make it simpler or does it make it faster?  What is the
performance impact?  Is the performance impact seen with or without
CONFIG_8xx_CPU6 enabled?  Without it, it looks like you're adding an
mtspr/mfspr combo in order to replace one mfspr.


More information about the Linuxppc-dev mailing list