On 07/20/2017 07:59 PM, Emilio G. Cota wrote:
Groundwork for supporting multiple TCG contexts.While at it, also allocate temps_used directly as a bitmap of the required size, instead of using a bitmap of TCG_MAX_TEMPS via TCGTempSet. Performance-wise we lose about 1.12% in a translation-heavy workload such as booting+shutting down debian-arm: Performance counter stats for 'taskset -c 0 arm-softmmu/qemu-system-arm \ -machine type=virt -nographic -smp 1 -m 4096 \ -netdev user,id=unet,hostfwd=tcp::2222-:22 \ -device virtio-net-device,netdev=unet \ -drive file=die-on-boot.qcow2,id=myblock,index=0,if=none \ -device virtio-blk-device,drive=myblock \ -kernel kernel.img -append console=ttyAMA0 root=/dev/vda1 \ -name arm,debug-threads=on -smp 1' (10 runs): exec time (s) Relative slowdown wrt original (%) --------------------------------------------------------------- original 20.213321616 0. tcg_malloc 20.441130078 1.1270214 TCGContext 20.477846517 1.3086662 g_malloc 20.780527895 2.8061013 The other two alternatives shown in the table are: - TCGContext: embed temps[TCG_MAX_TEMPS] and TCGTempSet used_temps in TCGContext. This is simple enough but it isn't faster than using tcg_malloc; moreover, it wastes memory. - g_malloc: allocate/deallocate both temps and used_temps every time tcg_optimize is executed. Suggested-by: Richard Henderson<r...@twiddle.net> Signed-off-by: Emilio G. Cota<c...@braap.org> --- tcg/optimize.c | 306 ++++++++++++++++++++++++++++++--------------------------- 1 file changed, 161 insertions(+), 145 deletions(-)
Reviewed-by: Richard Henderson <r...@twiddle.net> r~
