Hi, This patch set introduces a new instruction support on AMD Carrizo (Family 15h, Model 60h-6fh). It adds mwaitx delay function with a configurable timer.
Andy and Boris provide a suggestion which uses mwaitx on delay method. As Peter's suggestion of last version (v5), the serial of patch set provides a test result. http://marc.info/?l=linux-kernel&m=143436586513713&w=2 Some discussions of the background, please see: http://marc.info/?l=linux-kernel&m=143202042530498&w=2 http://marc.info/?l=linux-kernel&m=143161327003541&w=2 http://marc.info/?l=linux-kernel&m=143222815331016&w=2 Patch set is rebased on tip/master. Changes from v1 -> v2 - Remove mwaitx idle implementation since some disputes without power improvement. - Add a patch which implement another use case on delay. - Introduce a kernel parameter (delay) to make delay method configurable. Changes from v2 -> v3 - Add compared data on commit message - Remove kernel parameter - Add hint to avoid to access deep state in future - Update mwaitx delay method as Petter's suggestion Changes from v3 -> v4 - Put the MONITORX/MWAITX description into comments Changes from v4 -> v5 - Remove mwaitx function - Use mwaitx_delay at init_amd - Use cpu_tts as montioring address scope Changes from v5 -> v6 - Move definitions into patch 1 - Completed the power consumption testing both with MWAITX and without MWAITX - Use mwaitx_delay at bsp_init_amd In MWAITX delay, the CPU core will be quiesced in a waiting phase, diminishing its power consumption. Run a simple test to measure power consumption: cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc; sleep 10000s; cat /sys/bus/pci/devices/0000\:00\:18.4/hwmon/hwmon0/power1_acc; * TSC-based default delay: 485115 uWatts average power * MWAITX-based delay: 252738 uWatts average power Thus, that's about 240 milliWatts less power consumption. The test method relies on the support of AMD CPU accumulated power algorithm in fam15_power for which patches are forthcoming. Thanks, Rui Huang Rui (2): x86, mwaitt: add monitorx and mwaitx instruction x86, mwaitt: introduce mwaitx delay with a configurable timer arch/x86/include/asm/cpufeature.h | 1 + arch/x86/include/asm/delay.h | 1 + arch/x86/include/asm/mwait.h | 43 +++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/amd.c | 4 ++++ arch/x86/lib/delay.c | 48 ++++++++++++++++++++++++++++++++++++++- 5 files changed, 96 insertions(+), 1 deletion(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
