Windows System Software -- Consulting, Training, Development -- Unique Expertise, Guaranteed Results

Home NTDEV

More Info on Driver Writing and Debugging


The free OSR Learning Library has more than 50 articles on a wide variety of topics about writing and debugging device drivers and Minifilters. From introductory level to advanced. All the articles have been recently reviewed and updated, and are written using the clear and definitive style you've come to expect from OSR over the years.


Check out The OSR Learning Library at: https://www.osr.com/osr-learning-library/


Before Posting...

Please check out the Community Guidelines in the Announcements and Administration Category.

HalTranslateBusAddress/MmMapIoSpace memory slow?

OSR_Community_UserOSR_Community_User Member Posts: 110,217
Hello all,

An interesting result...I have set aside a large chunk of memory using
/MAXMEM. I am using HalTranslateBusAdress and MmMapIoSpace to address the
memory. The RtlCopyMemory() is about 4 times slower than copying memory
from within NT normal memory space! It does not seem to matter is
MmMapIoSpaces' Cache is TRUE or FALSE. The test uses a single RAM DIMM
for NT and the extra memory, so it has to do with the way the intel's
cache lines are being tugged around, but is there a solution?

TIA,
John
Sign In or Register to comment.

Howdy, Stranger!

It looks like you're new here. Sign in or register to get started.

Upcoming OSR Seminars
OSR has suspended in-person seminars due to the Covid-19 outbreak. But, don't miss your training! Attend via the internet instead!
Writing WDF Drivers 24 January 2022 Live, Online
Internals & Software Drivers 7 February 2022 Live, Online
Kernel Debugging 21 March 2022 Live, Online
Developing Minifilters 23 May 2022 Live, Online