I am currently writing a simple sata driver in PIO mode.(My hobby os don't have ahci driver yet, so I want to use pio)
My question is, how to emulate a sata disk in PIO mode in QEMU?
Thanks.
Related
I am testing website performance using chrome's audit extension on different devices.
The performance results are different for different devices for the same website. I ran tests on my machine, macbook and dell laptop.
Why the results are different every time? And does these tests run on local device or is it cloud based?
As you are running test using chrome extension which runs in local machine, so it will be slightly different for different platforms and it will also depends on the internet connectivity.
For better and more reliable testing of website, it is better to use simulator or on server based service because all the users might not be privileged of having better device or internet connection.
There are many server/cloud based services. Below are two of them which I use.
1) You can use web.dev using Google's Lighthouse
All tests are run using a simulated mobile device, throttled to a fast 3G network & 4x CPU slowdown.
2) You can use webpagetest. On this platform you can create your own simulation here.
This because the hardware and the CPU load can affect your results, even some chrome extensions can affect the performance.
I ran some tests over cerebry.co and I couldn't notice any significant difference between tests,I performed my tests on power save mode and in high performance mode, switching between WiFi 5GHz and 2.4GHz bands, with cache disabled.
-- Macbook 12 PRO MID 2012 i7 3rd gen 16GB ram SSD (3.4s - 5.7s)
-- HP Chromebook i7 8th gen 16GB ram SSD (3.2s - 4s)
-- ASUS ROG i5 7th gen 12GB ram NVME (3s- 3.4s)
-- HP ENVY i5 4th gen 12GB ram HDD 5.4K RPM (3.2s- 3.7s)
Maybe with older or slower HW I can experience a performance degradation.
So I recently have a project using MySQL 8.0.12, configured for Development Computer upon installation.
I developed the system on my PC, which has an i5 CPU with 8 GB RAM.
On my PC, the mysqld.exe process consumes around 10% of CPU usage and 20 MB of Memory when a continuous query is run
I then deployed this system to the client PC, which has an Atom CPU with 8 GB RAM. Also using a fresh install of MySQL 8.0.12.
For some reason, even on idle condition, the mysqld.exe process consumes 300 MB of Memory. Also the CPU usage goes up to 60% during continuous query.
Both system runs on Windows 10 x64-bit
Obviously the speed of these two computers are different, but I kind of doubt that the CPU core is the issue, since the idle state already consume different memory.
What may went wrong with this MySQL inside the Atom based PC? Why does it behave very differently? CPU Usage aside, it is very weird to me that the idle state memory consumption is so different.
Is there any possible workaround to these issues?
I'm currently running a VM without selecting a CPU type. How can I know which one is being emulated? Is there a way to ask this to the Qemu monitor?
Host machine is Windows 10 and guest is Plan 9. Not using KVM.
I am developing a WP8 app on a memory-constrained machine.
I can only run my app on the smaller-resolution emulator, but not the rest, because those require 1 GB of system ram.
How can I change the configuration for the emulators so that they use less memory?
I'm afraid there is no alternative but to add more RAM to your system (RAM is cheap these days).
For your information, here are the requirements for the Windows Phone 8 SDK:
6.5 GB of free hard disk space
4 GB RAM
64-bit (x64) CPU
Try the following solution
https://docs.google.com/document/d/1sTelfYz-oiQ98GSqPn-IBU7J0XTY24HocEU_mhxZFP0/edit?usp=sharing to edit static emulator RAM settings.
Does it make a difference? All I'll be doing (for the most part) is running different browsers. I would think the most stripped down one possible would be best.
Update: My dev box is a MacBook Pro (2010) with 8G ram, 2.4 GHz processor running Lion.
Ordinary Windows 7 installations are shipped with a full load of crap. Even the cleanest installs have a size of at least 10 GB. For that reason, I recommend to only use Windows 7 if you want to test IE9+ (which requires Vista+).
The following steps will take a maximum of ten minutes. Afterwards, you have a fully functioning Windows 7 + IE9 system, which takes only 2GB of physical space:
Getting Windows 7 Lite
I use this set-up in VirtualBox. I have not tested it in VMWare, but there should be no differences.
Get a Windows 7 Lite VM image.
I myself use an image, created by ivankehayov:
Download name: Win7.SP1.IE9.lite.v2-IK
ISO size: 700 MB (after installing: less 2GB)
MD5: 094BE542B3F292726EF7F16619CACA9A
For more information, and the tools used to create this image, see this forum. More details (about the old image) can be found here.
Creating/Installing the Virtual Machine
Create an new VM, and put the ISO image in the virtual CD slot.
2 GB RAM (Minimum of 1 GB, to ensure that your system doesn't crash).
Boot the Virtual Machine.
Install from the iso image
Decrease resource usage (4 steps)
Install CCleaner, to wipe (temporary) (log) files.
Disable System Protection:
Control Panel > System Protection > Configure... > Turn off system protection
Disable the page file (especially recommended when you've got a SSD).
Control Panel > Advanced system settings > Performance [Settings..] > Advanced > Virtual memory [Change..] > No paging file - Set. Confirm and reboot.
Disable all unnecessary services, to increase the booting speed.
Set your preferences (homepage? IE settings?), and save a snapshot of your VM. When you're done with using the VM, restore the snapshot. This will prevent Windows from hogging disk space over time, and keeps your VM image compact.
My virtual Windows 7 boots within 45 seconds.
Relevant details about my own environment:
- Virtualization software: Oracle VirtualBox
- Operating system: Linux-based
- RAM: 8 GB
- Disk: 60 GB SSD