understanding linux kernel 4th edition

True understanding of the red and black trees (a large amount of data structures used in the Linux kernel are often asked by the second party)As a data structure, the red and black trees are not simple, because various propaganda makes it too mysterious. I have collected a lot of articles about the red and black trees on the Internet, which are similar, introduci

Deep understanding of Linux kernel-skbuff 1, skb-> users and skb-> dataref differences skb-> users: when the number of references increases, this value and skb-> dataref both add skb-> dataref: When skb is cloned, only skb-> dataref is added, the cloned skb's skb-> users = 1 2, pskb-> copy and skb-> copy pskb-> copy: only copy the skb data structure, do not copy

Deep understanding of the key data structures of Linux kernel network technology-skbuff 1, skb-> users and skb-> dataref difference skb-> users: when the number of references increases, this value and skb-> dataref both add skb-> dataref: When skb is cloned, only skb-> dataref is added, the cloned skb's skb-> users = 12, pskb-> copy and skb-> copy pskb-> copy: on

1, three addressesA logical address, used in a machine language instruction, to specify an operand or an address of an instruction.Linear address: 32-bit unsigned integer up to 4GB. A 64-bit CPU is a 64-bit linear addressPhysical Address: Memory chip-level memory unit addressing. Old-fashioned x86 are represented by 32-bit or 36-bit unsigned integers.2,mmu Memory Control UnitA hardware circuit with a segmented unit converts a logical address to a linear addressA hardware circuit that has a pagin

the local statement (LDT). The GDT is stored in memory, and the address and size are placed in the GDTR control register. The LDT is placed in the LDTR control register.TSS: Task status segment. The task State is primarily represented by a number of registers, so this segment is used to hold the contents of the processor register. This segment is only in the GDT.Linear address: base+ logical address offset in the segment descriptorQuestion: What does the field mean in the segment descriptor?Dee

segment starting from 0 4, that is, the low cost of the logical address of Linux and the corresponding linear address of the value is always consistent2. How to convert a linear address to a physical address?Page: 4,096 bytes, including in-page addresses, dataPage box: physical page, 4096 bytes, without in-page dataPaging: For efficiency, the linear address is divided into fixed-length pages, the continuous linear address of the page is mapped to

Learn about Chinese contributions to Linux kernel over the past few years-general Linux technology-Linux technology and application information. The following is a detailed description. Mikeandmore Linux conference30 and more than three major card senders are Chinese One i

the logical addresses with a null segment selector would be considered invalid, thus causing a processor exce Ption.8, whenever the CPL is changed, some segmentation registers must was correspondingly updated. For instance, when the CPL was equal to 3 (user Mode), the DS register must contain the segment selector of the user data SE Gment, but when the CPL was equal to 0, the DS register must contain the segment selector of the kernel data segment9,

Memory addressWhen using a 80x86 microprocessor, the following three different addresses must be distinguished:1) Logical addresses (logical address), each logical address consists of a segment (segment) and offset (offset or displacement), the offset indicates the distance from the beginning of the segment to the actual address.2) A linear address (linear address), also known as virtual addresses, is a 32bit unsigned integer that can be used to represent the address of a 4G, usually represented

When looking at the Linux kernel source code, the struct List_head structure is often seen in some structures. Look for the source code, in the List.h, there is a definition of this structure, this is the Linux kernel of the linked list structure.With a closer look at the structure, you can see that it is quite differe