Methods and apparatus for data request scheduling in performing parallel IO operations
Methods and apparatus for data request scheduling in performing parallel IO operations are disclosed. In one example, IO requests directed to an operating system having an IO scheduling component are processed. There, an IO request directed from an application to the operating system is intercepted. A determination is made whether the IO request is subject to immediate processing using available parallel processing resources. When it is determined that the IO request is subject to immediate processing using the available parallel processing resources, the IO scheduling component of the operating system is bypassed. The IO request is directly and immediately processed and passed back to the application using the available parallel processing resources.
1. A method for handling Input/Output (I/O) requests directed to an operating system having an IO scheduling component, the method comprising:
intercepting an IO request directed from an application to the operating system;
determining whether the IO request is subject to immediate processing using available parallel processing resources; and
bypassing the IO scheduling component of the operating system when it is determined that the IO request is subject to immediate processing using the available parallel processing resources,
wherein said determining whether the IO request is subject to immediate processing comprises
querying a disk block cache status, and
determining that the IO request is subject to immediate processing where the disk block cache status query indicates availability to immediately process the IO request.
2. The method of claim 1 , wherein the availability to immediately process the IO request comprises a cache hit status where the IO request is a read request.
3. The method of claim 1 , wherein the availability to immediately process the IO request comprises an indication of write buffer availability where the IO request is a write request.
4. The method of claim 1 , wherein said determining whether the IO request is subject to immediate processing further comprises an adaptive determination of the available parallel processing resources.
5. The method of claim 1 , further comprising:
identifying a quality of service promised to the application originating the IO request; and
determining that the IO request is subject to immediate processing depending upon the quality of service promised to the application.
6. The method of claim 1 , further comprising:
determining historical demand information corresponding to IO request processing and application task processing; and
determining that the IO request is subject to immediate processing depending upon the historical demand information.
7. The method of claim 6 , further comprising:
determining instantaneous demand information; and
adjusting criteria for determining that the IO request is subject to immediate processing based upon the instantaneous demand information.
8. The method of claim 1 , further comprising:
determining that the IO request is subject to immediate processing depending upon at least one of a threshold number of processors for IO request processing, a quality of service promised to the application originating the IO request, or a demand level corresponding to IO request processing.
9. A method for handling Input/Output (I/O) requests directed to an operating system having an IO scheduling component, the method comprising:
intercepting an IO request directed from an application to the operating system;
determining whether the IO request is subject to immediate processing using available parallel processing resources;
bypassing the IO scheduling component of the operating system when it is determined that the IO request is subject to immediate processing using the available parallel processing resources;
determining a threshold number of processors for IO request processing; and
determining that the IO request is subject to immediate processing where a currently used number of processors for IO processing is below the threshold number.
10. A non-transitory computer readable medium storing program code for handling Input/Output (I/O) requests directed to an operating system having an IO scheduling component, the program code being executable by a processor to perform operations comprising:
intercepting an IO request directed from an application to the operating system;
determining whether the IO request is subject to immediate processing using available parallel processing resources; and
bypassing the IO scheduling component of the operating system when it is determined that the IO request is subject to immediate processing using the available parallel processing resources,
wherein determining whether the IO request is subject to immediate processing comprises
querying a disk block cache status, and
determining that the IO request is subject to immediate processing where the disk block cache status query indicates availability to immediately process the IO request.
11. The computer readable medium of claim 10 , wherein the availability to immediately process the IO request comprises a cache hit status where the IO request is a read request.
12. The computer readable medium of claim 10 , wherein the availability to immediately process the IO request comprises an indication of write buffer availability where the IO request is a write request.
13. The computer readable medium of claim 10 , wherein said determining whether the IO request is subject to immediate processing further comprises an adaptive determination of the available parallel processing resources.
14. The computer readable medium of claim 10 , wherein the operations further comprise:
identifying a quality of service promised to the application originating the IO request; and
determining that the IO request is subject to immediate processing depending upon the quality of service promised to the application.
15. The computer readable medium of claim 10 , wherein the operations further comprise:
determining historical demand information corresponding to IO request processing and application task processing; and
determining that the IO request is subject to immediate processing depending upon the historical demand information.
16. The computer readable medium of claim 15 , wherein the operations further comprise:
determining instantaneous demand information; and
adjusting criteria for determining that the IO request is subject to immediate processing based upon the instantaneous demand information.
17. The computer readable medium of claim 10 , wherein the operations further comprise:
determining that the IO request is subject to immediate processing depending upon at least one of a threshold number of processors for IO request processing, a quality of service promised to the application originating the IO request, or a demand level corresponding to IO request processing.
18. A non-transitory computer readable medium storing program code for handling Input/Output (I/O) requests directed to an operating system having an IO scheduling component, the program code being executable by a processor to perform operations comprising:
intercepting an IO request directed from an application to the operating system;
determining whether the IO request is subject to immediate processing using available parallel processing resources;
bypassing the IO scheduling component of the operating system when it is determined that the IO request is subject to immediate processing using the available parallel processing resources;
determining a threshold number of processors for IO request processing; and
determining that the IO request is subject to immediate processing where a currently used number of processors for IO processing is below the threshold number.