为什么我在性能列表中找不到硬件缓存事件?

为什么我在性能列表中找不到硬件缓存事件?

我在新买的笔记本电脑上使用 linux perf 时遇到问题:我的 perf 列表中没有可用的硬件缓存效果!嗯,这确实是我想要采样的所有重要信息!这是我的性能列表:

List of pre-defined events (to be used in -e):
cpu-cycles OR cycles                               [Hardware event]
instructions                                       [Hardware event]
cache-references                                   [Hardware event]
cache-misses                                       [Hardware event]
branch-instructions OR branches                    [Hardware event]
branch-misses                                      [Hardware event]
bus-cycles                                         [Hardware event]
ref-cycles                                         [Hardware event]

cpu-clock                                          [Software event]
task-clock                                         [Software event]
page-faults OR faults                              [Software event]
context-switches OR cs                             [Software event]
cpu-migrations OR migrations                       [Software event]
minor-faults                                       [Software event]
major-faults                                       [Software event]
alignment-faults                                   [Software event]
emulation-faults                                   [Software event]
dummy                                              [Software event]

branch-instructions OR cpu/branch-instructions/    [Kernel PMU event]
branch-misses OR cpu/branch-misses/                [Kernel PMU event]
bus-cycles OR cpu/bus-cycles/                      [Kernel PMU event]
cache-misses OR cpu/cache-misses/                  [Kernel PMU event]
cache-references OR cpu/cache-references/          [Kernel PMU event]
cpu-cycles OR cpu/cpu-cycles/                      [Kernel PMU event]
instructions OR cpu/instructions/                  [Kernel PMU event]
power/energy-cores/                                [Kernel PMU event]
power/energy-gpu/                                  [Kernel PMU event]
power/energy-pkg/                                  [Kernel PMU event]
power/energy-ram/                                  [Kernel PMU event]
ref-cycles OR cpu/ref-cycles/                      [Kernel PMU event]

rNNN                                               [Raw hardware event descriptor]
cpu/t1=v1[,t2=v2,t3 ...]/modifier                  [Raw hardware event descriptor]
(see 'man perf-list' on how to encode it)

mem:<addr>[:access]                                [Hardware breakpoint]

[ Tracepoints not available: Permission denied ]

这是我以前看到的性能列表:https://perf.wiki.kernel.org/index.php/Tutorial#Events

我以前做的事情是:

sudo perf stat -e L1-dcache-loads,L1-dcache-load-misses,LLC-loads,LLC-load-misses -a --append -o perf.txt [some command to run a file]

但这在我的新机器上不起作用。在这种情况下我怎样才能收集到我想要的数据呢?

我使用的是 Ubuntu 14.04,内核 <3.19.0-56>。性能版本 <3.19.8-ckt15>。


更新

我安装了papi-tools库,并papi_native_avail给了我

Available native events and hardware information.

PAPI Version             : 5.3.0.0
Vendor string and code   : GenuineIntel (1)
Model string and code    : Intel(R) Core(TM) M-5Y71 CPU @ 1.20GHz (61)
CPU Revision             : 4.000000
CPUID Info               : Family: 6  Model: 61  Stepping: 4
CPU Max Megahertz        : 2900
CPU Min Megahertz        : 500
Hdw Threads per core     : 1
Cores per Socket         : 2
Sockets                  : 2
NUMA Nodes               : 1
CPUs per Node            : 4
Total CPUs               : 4
Running in a VM          : no
Number Hardware Counters : 0
Max Multiplex Counters   : 64

答案1

另外值得注意的是,perf list根据它是否作为root. (也许有一些配置设置不是root决定因素;我不确定。)

在我的 Linux Mint 18.1 机器上,运行 4.8.0-34-generic 内核:


$ perf list cache

List of pre-defined events (to be used in -e):

$ sudo perf list cache

List of pre-defined events (to be used in -e):

  L1-dcache-load-misses                              [Hardware cache event]
  L1-dcache-loads                                    [Hardware cache event]
  L1-dcache-stores                                   [Hardware cache event]
  L1-icache-load-misses                              [Hardware cache event]
  LLC-load-misses                                    [Hardware cache event]
  LLC-loads                                          [Hardware cache event]
  LLC-store-misses                                   [Hardware cache event]
  LLC-stores                                         [Hardware cache event]
  branch-load-misses                                 [Hardware cache event]
  branch-loads                                       [Hardware cache event]
  dTLB-load-misses                                   [Hardware cache event]
  dTLB-loads                                         [Hardware cache event]
  dTLB-store-misses                                  [Hardware cache event]
  dTLB-stores                                        [Hardware cache event]
  iTLB-load-misses                                   [Hardware cache event]
  iTLB-loads                                         [Hardware cache event]
  node-load-misses                                   [Hardware cache event]
  node-loads                                         [Hardware cache event]
  node-store-misses                                  [Hardware cache event]
  node-stores                                        [Hardware cache event]

答案2

首先,检查处理器是否有硬件计数器。 Intel Haswell 架构停止在最新的处理器中提供硬件计数器(出于某种原因)。

其次,我会检查您是否可以通过例如查看硬件事件papi。如果 Ubuntu 提供了足够新的数据库,该命令papi_native_avail应该列出本机事件。

第三种可能是事件已经发生,但没有旧的支持perf。是的,Ubuntu 14.04 已经推出两年了,内核/工具可能无法完全支持当前的处理器。

答案3

我最近遇到了这个问题,但我找出了原因并成功解决了它。

起初,sudo perf list只给了我几行事件。

对于那些需要完整硬件事件perf且未显示的人perf-list,您需要安装最新的linux-tools

sudo apt-get install linux-tools-4.15.0-106-generic linux-cloud-tools-4.15.0-106-generic linux-tools-generic linux-cloud-tools-generic

然后,运行

sudo perf list > perflist.txt

让我看到 1980 行perflist.txt

相关内容