Memory bus attached input/output (‘I/O’) subsystem management in a computing system
View Patent ↗Memory bus attached Input/Output (‘I/O’) subsystem management in a computing system, the computing system including an I/O subsystem communicatively coupled to a memory bus, including: detecting, by an I/O subsystem device driver, a hibernation request; setting, by the I/O subsystem device driver, a predetermined memory address to a value indicating that the I/O subsystem is not to service system requests; detecting, by the I/O subsystem device driver, that the I/O subsystem device driver has been restarted; and setting, by the I/O subsystem device driver, the predetermined memory address to a value indicating that the I/O subsystem can resume servicing system requests.
1. A method of memory bus attached Input/Output (′I/O′) subsystem management in a computing system, the computing system including an I/O subsystem communicatively coupled to a memory bus, the method comprising:
detecting, by an I/O subsystem device driver, a hibernation request;
responsive to detecting the hibernation request, setting, by the I/O subsystem device driver, a predetermined memory address to a value indicating that the I/O subsystem is not to service system requests;
detecting, by the I/O subsystem device driver, that the I/O subsystem device driver has been restarted; and
setting, by the I/O subsystem device driver, the predetermined memory address to a value indicating that the I/O subsystem can resume servicing system requests.
2. The method of claim 1 wherein setting, by the I/O subsystem device driver, a predetermined memory address to the value indicating that the I/O subsystem is not to service system requests further comprises sending, by the I/O subsystem device driver to the I/O subsystem, a stop signal across the memory bus.
3. The method of claim 1 wherein setting, by the I/O subsystem device driver, the predetermined memory address to the value indicating that the I/O subsystem can resume servicing system requests further comprises sending, by the I/O subsystem device driver to the I/O subsystem, a start signal across the memory bus.
4. The method of claim 1 further comprising:
copying, by the I/O subsystem device driver, data from main memory to the I/O subsystem; and
responsive to setting the predetermined memory address to the value indicating that the I/O subsystem can resume servicing system requests, copying, by the I/O subsystem device driver, contents of the I/O subsystem to main memory.
5. The method of claim 1 wherein the I/O subsystem is dual in-line memory module (‘DIMM’) form factor flash memory.
6. The method of claim 1 further comprising:
retaining, by the I/O subsystem device driver in nonvolatile memory, I/O subsystem requests that were uncompleted when the hibernation request was detected; and
resuming, by the I/O subsystem device driver, the requests that were uncompleted.
7. The method of claim 6 wherein retaining I/O subsystem requests that were uncompleted when the hibernation request was detected includes masking the I/O subsystem requests.