How to build mkfs.erofs for ARM64

  |   File System  -  erofs   |   评论 (2)
mkfs.erofs is a user-space tool to create erofs filesystem images.erofs是华为为了增强安卓性能提出的自研文件系统，其内核文档提到用户态工具:The following git tree provides the file system user-spacetools under development ...阅读全文

如何测试cpufreq setpolicy driver

  |   Device Driver  -  cpufreq
上一篇说过有个cpufreq setpolicy patch涉及验证，qemu intel_pstate是不行了，主要是不支持X86_FEATURE_HWP or X86_FEATURE_APERFMPERF，只能在物理机上测试了。我的本本是E40(一代i3)，用了有点久了也不支持，intel_pstate是for SandyBridge arch，Intel从二代 i3...阅读全文

如何用QEMU运行x86 kernel

  |   Tools  -  qemu
最近在提交cpufreq patch，稍微有点逻辑改动的Rafael都要你test, test。有个改动涉及setpolicy driver，要验证，第一印象就是用qemu。让我们来看下如何搭环境(initrd=ramdisk):my linux server(xeon) for building can not access internet，also vb under...阅读全文

CPUFreq boost代码分析

  |   Performance  -  cpufreq, boost
参考4.9内核，还是先看文档描述：IntroductionSome CPUs support a functionality to raise the operating frequency ofsome cores in a multi-core package if certain conditions apply, mostlyif the whole chip i...阅读全文

Linux CPUFreq Subsystem Overview

  |   Performance  -  cpufreq
参考4.9，CPUFreq即CPU Frequency scaling或者CPU performance scaling，允许你运行时改变CPU clock speed.文档路径: ./Documentation/cpu-freq/，先来看几个概念：Some CPU frequency scaling-capable processor switch between va...阅读全文

Linux CMA代码分析

  |   Memory Management  -  cma
CMA全称Contiguous Memory Allocator，是Linux内核的连续内存分配器，最近就遇到一个因CMA分配失败导致的camera功能异常，log如下：<6>[ 3371.081458] alloc_contig_range: [8fa00, 8ff00) PFNs busy <6>[ 3371.081481] alloc_con...阅读全文
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11
  12. 12
  13. 13
  14. 14
  15. 15
  16. 16