Git Product home page Git Product logo

Comments (2)

huaicheng avatar huaicheng commented on July 30, 2024

Can you let me know how to measure 99.99th long tail latency?
Is it possible to measure latency of each I/O?

In your guest OS, you can run IO benchmark tools (e.g. FIO) to measure per-IO latencies (by enabling the per-IO latency log option "write_lat_log"), then you can calculate the CDF by yourself (e.g. I have a small tool here for that purpose: https://github.com/huaicheng/rtk). FIO output also contains some predefined percentiles.

Is it right that latency measurements in femu are made by recording in specific memory rather than delaying through 'sleep' command? I want to know exactly how measurements are made in femu.

In general, FEMU emulates IO delay transparent to the applications running in the guest OS. FEMU delay each IO for a certain amount of time before it returns the IO back to guest OS. The time to delay is decided by the FTL logic based on NAND latencies and queueing delays.

from femu.

KibeenJung avatar KibeenJung commented on July 30, 2024

thank you for your reply!

from femu.

Related Issues (20)

Recommend Projects

  • React photo React

    A declarative, efficient, and flexible JavaScript library for building user interfaces.

  • Vue.js photo Vue.js

    🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.

  • Typescript photo Typescript

    TypeScript is a superset of JavaScript that compiles to clean JavaScript output.

  • TensorFlow photo TensorFlow

    An Open Source Machine Learning Framework for Everyone

  • Django photo Django

    The Web framework for perfectionists with deadlines.

  • D3 photo D3

    Bring data to life with SVG, Canvas and HTML. 📊📈🎉

Recommend Topics

  • javascript

    JavaScript (JS) is a lightweight interpreted programming language with first-class functions.

  • web

    Some thing interesting about web. New door for the world.

  • server

    A server is a program made to process requests and deliver data to clients.

  • Machine learning

    Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.

  • Game

    Some thing interesting about game, make everyone happy.

Recommend Org

  • Facebook photo Facebook

    We are working to build community through open source technology. NB: members must have two-factor auth.

  • Microsoft photo Microsoft

    Open source projects and samples from Microsoft.

  • Google photo Google

    Google ❤️ Open Source for everyone.

  • D3 photo D3

    Data-Driven Documents codes.