rcu calculator

There are two RCU implementations in kernel, one is tiny RCU and the other is tree RCU. Both of these RCU were formerly classic RCU.If you want to read the classic RCU implementation code, you must find kernel 2.6.26, because in kernel 2.6.27,classic

Kernel/documentation/rcu.txt The basic idea of RCU (read-copy update) is to divide a destruction operation into two steps: the first step is that when the writer is destroying, no reader will notice the existence of the destruction action; the second step is to execute real destruction. There is a "Grace Period"/grace period/quiet period/between the two. This grace period must be long enough to ensure that the reader who reads the deleted items has co

Tags: SPI release bat. NET kernel mit atomic URL launchFirst, prefaceBecause I have worked on Linux2.6.23 for many years, I am very emotional about this version (aside from emotional factors, should have chosen longterm 2.6.32 version to analyze, ^_^), This article mainly describes what fixes are available for RCU in the Linux2.6.23 kernel version. The so-called amendments consist of two parts, some of which are bug fixed, and some are new features.Se

First, prefaceThe documentation on RCU consists of two parts, one on basic principles (this is the article) and one on the implementation of Linux kernel. The second chapter describes why there is RCU this synchronization mechanism, especially in the increasing number of CPU cores today, a better performance of the synchronization mechanism is how to solve the problem, of course, the best tools have its app

In a long time, probably 2009, wrote an article on the Linux RCU lock "RCU lock in the evolution of the Linux kernel", and now I admit that while I understand the RCU lock, but I do not have the ability to use a very simple description of the implementation of Linux to show it, Saying goes you can give others a very concise description in your own way, you are re

At a very early time, probably in the 2009. Wrote an article on the Linux RCU lock "RCU lock in the evolution of the Linux kernel", I now admit. At that time I understand the RCU lock, but I do not have the ability to use a very easy description of the implementation of Linux to show out, saying goes you can give others in your own way very concise description of

Tag: Perform a return server note on-line CAL understanding content InitializationOpenvswitch (OVS) source code of Linux RCU lock mechanism analysisCategory: Linux kernels | Tags: cloud computing, Openvswitch,linux kernel, RCU lock mechanism |Yuzhihui_no1 Related |Release Date: 2014-10-19 | Heat: 1044°ObjectiveI would like to continue to analyze Upcall calls along the processing flow of the packet, but foun

RCU principle: RCU (read-copy update), as its name implies, is read-copy modification. It is named based on its principle. For the shared data structure protected by RCU, the reader can access it without getting any locks, but the writer first copies a copy when accessing it and then modifies the copy, finally, a callback mechanism is used to re-point the poin

Tags: style blog http io ar color OS sp forRun Repository Creation Utility (RCU) for Oracle Identity Management components Installing Oracle Fusion Applications > Setting up Identity and Access Management Node > Run Repository Creation Uti Lity (RCU) for Oracle Identity Management componentsPrevious: Install Oracle 11g Database (Identity management database)RCU

Transferred from: http://blog.chinaunix.net/uid-23769728-id-3080134.htmlThe design idea of RCU is more clear, and the method of replacing the new and old pointers can realize the sharing protection of lock-free mode. But to the level of the code, it will be difficult to understand how much. In the 4th chapter of the deep Linux device driver kernel mechanism, the rules behind RCU have been very clearly descr

The RCU of lock mechanism in Linux kernel, the big kernel lockIn the last blog post, the author analyzes the use of completion and mutual exclusion and some classic questions, the following author will focus on this blog post on the RCU mechanism of the relevant content and introduce the current has been eliminated from the kernel of the large kernel lock (BKL). At the end of this article, we summarize the

In a system there is a write thread and several read threads, and the read-write thread uses a pointer to share a data structure, the write thread overwrites the structure, and the read thread reads the structure. In the process of rewriting this data structure by a write thread, the read thread will increase in lock-up time because of waiting for the lock.You can take advantage of the idea of RCU (Read Copy Update What's

There are many synchronization mechanisms in the Linux kernel. The classic ones include spin_lock (waiting lock), mutex (mutex lock), semaphore (semaphore), and so on. And almost all of them have corresponding rw_xxx (read/write locks), so that the read operations are mutually exclusive (read/write and write are still mutually exclusive) when the read and write operations can be distinguished ). Seqlock and RCU should not be included in the classic co

RCU (Read-copy Update) is a way of synchronizing data and plays an important role in the current Linux kernel. RCU is mainly for the data object is linked list, the purpose is to improve the efficiency of traversing read data, in order to achieve the purpose of using the RCU mechanism to read data when the linked list does not time-consuming lock operation. This

as sysdbasql> show parameter processes; SQL> shutdow Immediate; The number of Oracle routines has been closed. SQL> startup;oracle routines have been started. Rcu-6107:_b_tree_bitmap_plans Database initialization parameter Prerequisites failedThe current value is null. The value should be null FALSE.Set " _b_tree_bitmap_plans "=false;Rcu-6107:db_securefile Database initialization parameter Prerequisites fai

Delete Database Endv (original RCU database) Rebuild database to LLS (new RCU database): Slightly..The Database Control URL is https://www:1158/emThe management repository is placed in safe mode, in which Enterprise Manager data is encrypted. The encryption key has been placed in the file D:/app/administrator/product/11.2.0/dbhome_1/www_lls/sysman/config/emkey.ora. Be sure to back up this file, because if t

RCU is a Linux system read-write synchronization mechanism, in the final analysis he is also a kind of kernel synchronization means, this question on the RCU probability and implementation mechanism, give the author's understanding."Rcu probability"Let's look at the definition of RCU in the kernel document:RCU is a syn

passively wait, this wait is very boring!Can I combine the way I read and write locks?How to combine? According to just the idea, nothing is to write a passive wait or the first reader to make a decision! But it has another option: to write the data according to its own process, not to write the original data, but to write a copy of the original data (a great write-time copy) and then hang it on a list of unfinished transactions, waiting for the system to find that all the readers are done with

Transferred from: http://blog.csdn.net/goodluckwhh/article/details/9006065Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.Directory (?) [-] A signal volume The concept of signal volume Semaphore data structures and related APIs Data Initialization Acquiring and releasing semaphores The concept of Read and write semaphores Data structures for reading and writing semaphores

Tags: embedded tree date Analysis special difficult small concurrent taskRCU (Read-copy Update) is a new type of read-write lock with a relatively mature Linux kernel, which has high read-write concurrency performance and is often used for performance critical paths that require mutual exclusion. In kernel, RCU has tiny rcu and tree RCU two implementations, tiny