2024-10-10发表linux / 性能优化16 分钟读完 (大约2455个字)

概述

perf 是一个强大的 Linux 性能分析工具，它可以用来收集和分析性能数据。

perf的命令有很多，下文将就其中常用的几条进行阐述


usage: perf [--version] [--help] [OPTIONS] COMMAND [ARGS]

The most commonly used perf commands are:
  annotate        Read perf.data (created by perf record) and display annotated code
  archive         Create archive with object files with build-ids found in perf.data file
  bench           General framework for benchmark suites
  buildid-cache   Manage build-id cache.
  buildid-list    List the buildids in a perf.data file
  c2c             Shared Data C2C/HITM Analyzer.
  config          Get and set variables in a configuration file.
  daemon          Run record sessions on background
  data            Data file related processing
  diff            Read perf.data files and display the differential profile
  evlist          List the event names in a perf.data file
  ftrace          simple wrapper for kernel's ftrace functionality
  inject          Filter to augment the events stream with additional information
  iostat          Show I/O performance metrics
  kallsyms        Searches running kernel for symbols
  kvm             Tool to trace/measure kvm guest os
  list            List all symbolic event types
  mem             Profile memory accesses
  record          Run a command and record its profile into perf.data
  report          Read perf.data (created by perf record) and display the profile
  script          Read perf.data (created by perf record) and display trace output
  stat            Run a command and gather performance counter statistics
  test            Runs sanity tests.
  top             System profiling tool.
  version         display the version of perf binary
  probe           Define new dynamic tracepoints
  trace           strace inspired tool
  kmem            Tool to trace/measure kernel memory properties
  kwork           Tool to trace/measure kernel work properties (latencies)
  lock            Analyze lock events
  sched           Tool to trace/measure scheduler properties (latencies)
  timechart       Tool to visualize total system behavior during a workload

See 'perf help COMMAND' for more information on a specific command.

安装

2024-09-18发表linux / linux内核8 分钟读完 (大约1240个字)

linux二进制文件加载源码分析

linux二进制加载

结构

linux_binfmt 用来定义二进制格式的结构，代表某种特定的格式，比如elf

struct linux_binfmt {
	struct list_head lh; // 链表头部
	struct module *module; // 模块
	int (*load_binary)(struct linux_binprm *); // 加载函数
	int (*load_shlib)(struct file *);
#ifdef CONFIG_COREDUMP
	int (*core_dump)(struct coredump_params *cprm); // coredump处理函数，如elf会有定义
	unsigned long min_coredump;	/* minimal dump size */
#endif
} __randomize_layout;