perf常用命令（perf top perf record perf stat）

perf top

通过-e指定关注的事件，比如查看造成cache miss最多的函数排行

perf top -e cache-misses

perf top -e task-clock

perf top -G // 得到调用关系图

perf top-e cache-misses -G // 得到调用关系图

perf top -e cycles // 指定性能事件

perf top -p 23015,32476 //查看这两个进程的cpu cycles使用情况

perf top -s comm,pid,symbol // 显示调用symbol的进程名和进程号

perf top --comms nginx,top // 仅显示属于指定进程的符号

perf top --symbols kfree // 仅显示指定的符号

perf stat

perf stat -e task-clock -e context-switches -p 进程号
perf stat -e stalled-cycles-frontend -p 进程号

perf stat -r 50 ls

Perf可以帮你统计N次结果的数值波动情况：

perf stat --repeat 5 -e kmem:mm_page_pcpu_drain -e kmem:mm_page_alloc -e kmem:mm_pagevec_free -e kmem:mm_page_free_direct ./t2 10

perf record -a

perf report

perf record –e cpu-clock ./t1

perf report

Perf list，perf 事件

使用 perf list 命令可以列出所有能够触发 perf 采样点的事件。

Hardware Event 是由 PMU 硬件产生的事件，比如 cache 命中，当您需要了解程序对硬件特性的使用情况时，便需要对这些事件进行采样；

Software Event 是内核软件产生的事件，比如进程切换，tick 数等 ;

Tracepoint event 是内核中的静态 tracepoint 所触发的事件，这些 tracepoint 用来判断程序运行期间内核的行为细节，比如 slab 分配器的分配次数等。

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]
stalled-cycles-frontend OR idle-cycles-frontend [Hardware event]
stalled-cycles-backend OR idle-cycles-backend [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]

L1-dcache-loads [Hardware cache event]
L1-dcache-load-misses [Hardware cache event]
L1-dcache-stores [Hardware cache event]
L1-dcache-store-misses [Hardware cache event]
L1-dcache-prefetches [Hardware cache event]
L1-dcache-prefetch-misses [Hardware cache event]
L1-icache-loads [Hardware cache event]
L1-icache-load-misses [Hardware cache event]
L1-icache-prefetches [Hardware cache event]
L1-icache-prefetch-misses [Hardware cache event]
LLC-loads [Hardware cache event]
LLC-load-misses [Hardware cache event]
LLC-stores [Hardware cache event]
LLC-store-misses [Hardware cache event]
LLC-prefetches [Hardware cache event]
LLC-prefetch-misses [Hardware cache event]
dTLB-loads [Hardware cache event]
dTLB-load-misses [Hardware cache event]
dTLB-stores [Hardware cache event]
dTLB-store-misses [Hardware cache event]
dTLB-prefetches [Hardware cache event]
dTLB-prefetch-misses [Hardware cache event]

iTLB-loads [Hardware cache event]
iTLB-load-misses [Hardware cache event]
branch-loads [Hardware cache event]
branch-load-misses [Hardware cache event]
node-loads [Hardware cache event]
node-load-misses [Hardware cache event]
node-stores [Hardware cache event]
node-store-misses [Hardware cache event]
node-prefetches [Hardware cache event]
node-prefetch-misses [Hardware cache event]

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

sunrpc:rpc_call_status [Tracepoint event]
sunrpc:rpc_bind_status [Tracepoint event]
sunrpc:rpc_connect_status [Tracepoint event]
sunrpc:rpc_task_begin [Tracepoint event]
sunrpc:rpc_task_run_action [Tracepoint event]

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