对于cache miss,perf会使用相应的计数器来记录缓存未命中的次数。 在x86架构中,perf使用的是指令计数器(Instruction Counter)和缓存计数器(Cache Counter)来统计cache miss。指令计数器记录了程序执行的指令数,而缓存计数器记录了缓存未命中的次数。通过这两个计数器的比值,可以得到缓存未命中率。 为了获取准确的cache...
现代CPU中的性能计数器(performance counters)是特殊的硬件寄存器。这些寄存器在不影响内核或应用性能的情况下统计诸如指令执行、cache miss、分支预取失败等硬件事件。如果我们给它们传递具体的周期数,这些性能计数器也可以在计数到达该周期时触发中断,从而对此时CPU上运行的应用进行采样剖析(Profiling)。 Linux 性能计数器...
Performance counter statsfor'./miss':88,780L1-dcache-load-misses0.009002291seconds time elapsed0.009174000seconds user0.000000000seconds sys [root@bogon c++]# perf stat -e L1-dcache-load-misses ./miss1Performance counter statsfor'./miss 1':1,015,683L1-dcache-load-misses0.012000335seconds time el...
CONFIG_PREEMPT_RT=y +#Performance monitor support +CONFIG_HW_PERF_EVENTS=y +CONFIG_ARM_PMU=y +CONFIG_ARM_DSU_PMU=y lynch@Meta:~/workspace/docker_env/user_home/RZG2L_V2/RZG2L/myir-renesas-linux$ 3)使用perf list cache命令,确认cache相关的event,已经开启。 List of pre-defined events (to...
现代CPU中的性能计数器(performance counters)是特殊的硬件寄存器。这些寄存器在不影响内核或应用性能的情况下统计诸如指令执行、cache miss、分支预取失败等硬件事件。如果我们给它们传递具体的周期数,这些性能计数器也可以在计数到达该周期时触发中断,从而对此时CPU上运行的应用进行采样剖析(Profiling)。
用linux perf命令来分析程序的cpu cache miss现象 #include#include int main(int argc, char **argv) { int a[1000][1000]; if(1 == argc) { for(int i = 0; i < 1000; ++i) { for(int j = 0; j < 1000; ++j) { a[i][j] = 0; ...
{PERF_COUNT_HW_CACHE_OP_PREFETCH, "hw-cache-op-prefetch"}, }; static const ConfigTable PERF_HW_CACHE_OP_RESULT_CONFIGS = { {PERF_COUNT_HW_CACHE_RESULT_ACCESS, "hw-cache-result-access"}, {PERF_COUNT_HW_CACHE_RESULT_MISS, "hw-cache-result-miss"}, }; static const ...
PERF_COUNT_HW_CACHE_MISSES Cache misses. Usually this indicates Last Level Cache misses; this is intended to be used in conjunction with the PERF_COUNT_HW_CACHE_REFERENCES event to calculate cache miss rates. PERF_COUNT_HW_BRANCH_INSTRUCTIONS ...
Hardware [Cache] Events: CPU相关计数器 CPU周期、指令重试,内存间隔周期、L2CACHE miss等 These instrument low-level processor activity basedonCPUperformancecounters. For example, CPU cycles, instructions retired, memory stall cycles, level2cache misses, etc. ...
For Armv8.1-m processors that implement the PMU, it is easy to measure the CPI (Cycle per Instruction) and L1 DCache miss rate with the macro __cpu_perf__(). Syntax: __cpu_perf__(<Description String for the target>, [User Code, see ref 1]) { //! target code segment of measu...