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

  • On-demand Event Event Date: May 18, 2015 While the idea of using facial and/or gesture recognition to create a modern, intuitive game seems attractive, some developers may want to leverage Unity 3D as a way to accelerate their development efforts. There are many different ways in which Intel and Unity Technologies have been working together to help speed the development of games with the Intel&reag; RealSense™ SDK (software developer kit). Check out this webcast to join a panel of experts as they …

  • This white paper focuses on how to protect and restore Microsoft Exchange data with Veeam. It briefly covers Microsoft Exchange 2013 and Veeam Backup & Replication v8 architecture, after which it focuses on how to handle proper backup, replication and recovery of Exchange in vSphere and Hyper-V environments.

Most Popular Programming Stories

More for Developers

RSS Feeds

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