Processes running at a higher IRQL will pre-empt a thread or interrupt running at a lower IRQL. An IRQL of 0 means that the processor is running a normal Kernel or User mode process. An IRQL of 1 means that the processor is running an Asynchronous Procedure Call (APC) or Page Fault. IRQL 2 is used for deferred procedure calls (DPC) and thread scheduling. IRQL 2 is known as the DISPATCH_LEVEL.
https://blogs.technet.microsoft.com/askperf/2008/01/22/what-is-irql-and-why-is-it-important/
I’ve found myself explaining IRQL a lot lately, sometimes to people who want to know because they’re trying to write Windows drivers and sometimes to people who are accustomed to Linux or some other variant of Unix and they want to know why something like IRQL is required within Windows when those systems so clearly get by without it.
https://blogs.msdn.microsoft.com/doronh/2010/02/02/what-is-irql/
Each processor has an independent IRQL, which descripts the current IRQL of the processor, i.e. the IRQL of the current instructions / codes being executed by this processor. System support a kernel routine (KeGetCurrentIRQL) to get current processors IRQL.
http://ext2fsd.sourceforge.net/documents/irql.htm
The IRQL values are divided into two groups: Software ( 0,1,2 ) / Hardware IRQL ( >= 3). Hardware IRQL is for device ISRs and system, it is similar to (but distinguished with) the level of hardware IRQ, which implemented by i8259, but IRQL is only an action of Windows OS, not hardwares. Its realized by Windows OS. But hardware IRQ level is achieved by 8259A (programmable interrupt controlor).
http://ext2fsd.sourceforge.net/documents/irql.htm
This routine is very simple. It tells us that current IRQL stores at krenel address 0xffdff024. And its a WORD (2 bytes), in fact its only one byte long, the upper 8 bits are zero. The value of IRQL can be one of the followings.
http://ext2fsd.sourceforge.net/documents/irql.htm
From Wikipedia, the free encyclopedia. An Interrupt Request Level (IRQL) is a hardware independent means with which Windows prioritizes interrupts that come from the system's processors. On processor architectures which Windows runs on, hardware generates signals which are sent to an interrupt controller.
https://en.wikipedia.org/wiki/IRQL_(Windows)
When it occurs in kernel mode, it generates a STOP 0x0000000A message. If you encounter this error while upgrading to a newer version of Windows, it might be caused by a device driver, a system service, a virus scanner, or a backup tool that is incompatible with the new version.
https://msdn.microsoft.com/en-us/library/ms854226.aspx
What is IRQL and why is it important? When people first hear the term IRQL (pronounced Er-kel) their thoughts sometimes turn to the sitcom Family Matters and Jaleel White’s alter ego, Steve Urkel. However, we’re not going to be taking a trip down Television’s Memory Lane today.
https://blogs.technet.microsoft.com/askperf/2008/01/22/what-is-irql-and-why-is-it-important/
Error Message: IRQL_NOT_LESS_OR_EQUAL. This Stop message indicates that a kernel-mode process or driver attempted to access a memory address to which it did not have permission to access. The most common cause of this error is an incorrect or corrupted pointer that references an incorrect location in memory.
https://msdn.microsoft.com/en-us/library/ms854226.aspx
IRQL (Windows) An Interrupt Request Level (IRQL) is a hardware independent means with which Windows prioritizes interrupts that come from the system's processors. On processor architectures which Windows runs on, hardware generates signals which are sent to an interrupt controller.
https://en.wikipedia.org/wiki/IRQL_(Windows)
what is irql
An Interrupt Request Level is a hardware independent means with which Windows prioritizes interrupts that come from the system's processors. An Interrupt Request Level or IRQL is a hardware independent means with which Windows prioritizes interrupts that come from the system's processors.