Articles Written by John Gulbrandsen

System Call Optimization with the SYSENTER Instruction

Windows NT calls system services by using an "int 2e" software interrupt. The "int 2e" instruction uses both an interrupt gate and a code segment descriptor to find the interrupt service routine (KiSystemService) which services the "int 2e" software interrupt. Since the CPU will have to load one interrupt gate and one segment descriptor from memory in order to know what interrupt service routine to call, significant overhead is involved in making an "int 2e" system call. The SYSENTER instruction drastically reduces this overhead.

How Do Windows NT System Calls REALLY Work?

Learn about the exact mechanism that Windows NT uses when switching to kernel mode to execute a system service. The description is for an x86-compatible CPU running in protected mode. Other platforms supported by Windows NT will have a similar mechanism for switching to kernel mode.

Top White Papers and Webcasts

  • Today's enterprise datacenter can be one of the most complex business environments with dozens (for smaller business), hundreds (for larger and midsize business), even thousands (for hyperscale businesses) of servers that must be managed and monitored. At this level, just managing the cords can be challenging — let alone keeping up with the growing need for more agility and scalability within the datacenter. Simply put, companies are aggressively looking for less complexity and more agility from their …

  • Essential Insights for Successful Cloud Migration and Management Whether you're planning your cloud migration strategy or already in the cloud, making accurate cloud decisions requires a deep analytical approach. This paper discusses the main objectives to achieve, top questions to ask, and the analytics you need at each stage of your cloud journey. You'll learn: How to identify which cloud provider will provide the best cost and performance benefits for your organization How to determine which applications …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date