valgrind massif 分析内存问题

旧博文，搬到 csdn
原文：http://rebootcat.com/2020/06/16/valgrind_massif_memory_analysing/

Valgrind Massif

valgrind 是什么，这里直接引用其他人的博客：

Valgrind是一套Linux下，开放源代码（GPL
V2）的仿真调试工具的集合。Valgrind由内核（core）以及基于内核的其他调试工具组成。

内核类似于一个框架（framework），它模拟了一个CPU环境，并提供服务给其他工具；而其他工具则类似于插件 (plug-in)，利用内核提供的服务完成各种特定的内存调试任务。

Valgrind的体系结构如下图所示：

Massif 命令行选项

关于 massif 命令行选项，可以直接查看 valgrind 的 help 信息：

MASSIF OPTIONS
       --heap=<yes|no> [default: yes]
           Specifies whether heap profiling should be done.

       --heap-admin=<size> [default: 8]
           If heap profiling is enabled, gives the number of administrative bytes per block to use. This should be an estimate of the average, since it may vary. For example, the
           allocator used by glibc on Linux requires somewhere between 4 to 15 bytes per block, depending on various factors. That allocator also requires admin space for freed blocks,
           but Massif cannot account for this.

       --stacks=<yes|no> [default: no]
           Specifies whether stack profiling should be done. This option slows Massif down greatly, and so is off by default. Note that Massif assumes that the main stack has size zero
           at start-up. This is not true, but doing otherwise accurately is difficult. Furthermore, starting at zero better indicates the size of the part of the main stack that a user
           program actually has control over.

       --pages-as-heap=<yes|no> [default: no]
           Tells Massif to profile memory at the page level rather than at the malloc'd block level. See above for details.

       --depth=<number> [default: 30]
           Maximum depth of the allocation trees recorded for detailed snapshots. Increasing it will make Massif run somewhat more slowly, use more memory, and produce bigger output
           files.

       --alloc-fn=<name>
           Functions specified with this option will be treated as though they were a heap allocation function such as malloc. This is useful for functions that are wrappers to malloc or
           new, which can fill up the allocation trees with uninteresting information. This option can be specified multiple times on the command line, to name multiple functions.

           Note that the named function will only be treated this way if it is the top entry in a stack trace, or just below another function treated this way. For example, if you have a
           function malloc1 that wraps malloc, and malloc2 that wraps malloc1, just specifying --alloc-fn=malloc2 will have no effect. You need to specify --alloc-fn=malloc1 as well.
           This is a little inconvenient, but the reason is that checking for allocation functions is slow, and it saves a lot of time if Massif can stop looking through the stack