内核zone里有个水位的概念，根据这个水位判断内存压力，从而进行内存回收,版本3.18。 struct zone { /* Read-mostly fields */ /* zone watermarks, access with *_wmark_pages(zone) macros */ unsigned long watermark[NR_WM...

kernel版本是3.18，先看下内存描述几个概念。 zone 概念NUMA全称Non-Uniform Memory Access,主要说的是cpu访问memory bank依赖他们之间的距离成本问题。 memory被划分成bank，每一个bank叫做node，每一个node被分成很多块叫zones, node用pglist_data表示, zone里包含p...

一般Linux内核统计剩余内存都是meminfo的MemFree+Cached, maybe + Buffers, 如下: xxxx:/ # cat /proc/meminfoMemTotal: 1883144 kBMemFree: 66536 kBMemAvailable: 724464 kBBuffers: ...

arm64/kernel3.18的定义在arch/arm64/include/asm/memory.h里 #ifndef __ASSEMBLY__#define __pa(x) __virt_to_phys((unsigned long)(x))#define __va(x) ...

I’m reading code about in kernel lowmemorykiller, lets know about some concepts related. vmpressure: monitor Linux virtual memory management pressure kernel page reclaim: backgr...

目标就是找到一种简单的量化测试方法 apk启动时间测量方法一：利用am start一般看TotalTime，多取几次算平均。 // adb shell am start -w packagename/MainActivityxxx:/ # am start -W com.android.settings/com.android.settings.Settin...

take a picture No module named pywapi download address: https://github.com/kapt/pywapi No module named psutil download address: https://github.com/packages/psutil No file n...

之前调了在Bootloader下bring up secondary cpu， arch是armv7， gic v2,记录下。 Hardware logic+----------+ +------------+ +-------------+ +------------+ +----+|soc timer ...

上半部分分析了kmap_atomic里的low memory page地址的获取，那如何获取high memory page的virtual address呢。 kmap_atomic分析入口就是pagefault_disable，查看定义： /* * These routines enable/disable the pagefault handler i...

目录 What is high memory kmap_atomic kunmap_atomic What is high memory先看下内核文档kernel3.18 vm/highmem.txt的说明： High memory (highmem) is used when the size of physical memory appr...