From c7ab62bfbe0e27ef452d19d88b083f01e99f13a7 Mon Sep 17 00:00:00 2001 From: Huang Rui Date: Wed, 9 Mar 2016 13:45:06 +0800 Subject: perf/x86/amd/power: Add AMD accumulated power reporting mechanism Introduce an AMD accumlated power reporting mechanism for the Family 15h, Model 60h processor that can be used to calculate the average power consumed by a processor during a measurement interval. The feature support is indicated by CPUID Fn8000_0007_EDX[12]. This feature will be implemented both in hwmon and perf. The current design provides one event to report per package/processor power consumption by counting each compute unit power value. Here the gory details of how the computation is done: * Tsample: compute unit power accumulator sample period * Tref: the PTSC counter period (PTSC: performance timestamp counter) * N: the ratio of compute unit power accumulator sample period to the PTSC period * Jmax: max compute unit accumulated power which is indicated by MSR_C001007b[MaxCpuSwPwrAcc] * Jx/Jy: compute unit accumulated power which is indicated by MSR_C001007a[CpuSwPwrAcc] * Tx/Ty: the value of performance timestamp counter which is indicated by CU_PTSC MSR_C0010280[PTSC] * PwrCPUave: CPU average power i. Determine the ratio of Tsample to Tref by executing CPUID Fn8000_0007. N = value of CPUID Fn8000_0007_ECX[CpuPwrSampleTimeRatio[15:0]]. ii. Read the full range of the cumulative energy value from the new MSR MaxCpuSwPwrAcc. Jmax = value returned. iii. At time x, software reads CpuSwPwrAcc and samples the PTSC. Jx = value read from CpuSwPwrAcc and Tx = value read from PTSC. iv. At time y, software reads CpuSwPwrAcc and samples the PTSC. Jy = value read from CpuSwPwrAcc and Ty = value read from PTSC. v. Calculate the average power consumption for a compute unit over time period (y-x). Unit of result is uWatt: if (Jy < Jx) // Rollover has occurred Jdelta = (Jy + Jmax) - Jx else Jdelta = Jy - Jx PwrCPUave = N * Jdelta * 1000 / (Ty - Tx) Simple example: root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' make -j4 CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL scripts/checksyscalls.sh CHK include/generated/compile.h SKIPPED include/generated/compile.h Building modules, stage 2. Kernel: arch/x86/boot/bzImage is ready (#40) MODPOST 4225 modules Performance counter stats for 'system wide': 183.44 mWatts power/power-pkg/ 341.837270111 seconds time elapsed root@hr-zp:/home/ray/tip# ./tools/perf/perf stat -a -e 'power/power-pkg/' sleep 10 Performance counter stats for 'system wide': 0.18 mWatts power/power-pkg/ 10.012551815 seconds time elapsed Suggested-by: Peter Zijlstra Suggested-by: Ingo Molnar Suggested-by: Borislav Petkov Signed-off-by: Huang Rui Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Thomas Gleixner Cc: Alexander Shishkin Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Brian Gerst Cc: David Ahern Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Namhyung Kim Cc: Robert Richter Cc: Stephane Eranian Cc: Vince Weaver Cc: jacob.w.shin@gmail.com Link: http://lkml.kernel.org/r/1457502306-2559-1-git-send-email-ray.huang@amd.com [ Fixed the modular build. ] Signed-off-by: Ingo Molnar --- include/linux/perf_event.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'include/linux/perf_event.h') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 7bb315bec3aa..15588d4c581d 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -129,6 +129,10 @@ struct hw_perf_event { struct { /* itrace */ int itrace_started; }; + struct { /* amd_power */ + u64 pwr_acc; + u64 ptsc; + }; #ifdef CONFIG_HAVE_HW_BREAKPOINT struct { /* breakpoint */ /* -- cgit v1.2.1