Patent
1996-11-26
1999-03-23
An, Meng-Al T.
395826, 395856, 39520036, 39520037, G06F 1300
Patent
active
058871918
ABSTRACT:
Response time jitter for high priority commands in a multimedia datastreaming system is bounded by issuing only non-blocking I/Os and by limiting the number of concurrent SCSI bus commands. A device driver in the system bounds the maximum time a VCR command must wait after it is released from a VCR queue by limiting the number of I/Os on the bus to a predetermined number functionally related to the magnitude of jitter permitted in the deterministic response requirement, and the time required for each data I/O to be issued to the decoder card. The number is such that the I/Os may issue within the jitter time with enough time remaining for issuance of a high priority VCR I/O. By limiting the I/Os to a predetermined number, the I/Os issued are constrained to be non-blocking to avoid hanging the I/O scheduler when a deterministic hhigh priority command arrives. A consequence of allowing only a limited predetermined number of I/Os is that all I/Os issued must be non-blocking to avoid the scheduler hanging at a time when a deterministic command arrives. Accordingly, the driver tracks the state of each decoder card and, in particular, the number of free buffers which can accept input data. The driver thereby ensures that the decoder card will not block before issuing a write I/O.
REFERENCES:
patent: 4931950 (1990-06-01), Isle et al.
patent: 5455942 (1995-10-01), Mohan et al.
patent: 5463624 (1995-10-01), Hogg et al.
patent: 5528513 (1996-06-01), Vaitzblit et al.
patent: 5544317 (1996-08-01), Berg
patent: 5692193 (1997-11-01), Jagannatan et al.
Adiga Ashok Kakkunje
Girouard Janice Marie
Shaw Wade David
An Meng-Al T.
Carwell Robert M.
Etienne Ario
International Business Machines - Corporation
LandOfFree
System and method for bounding response time jitter for high pri does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with System and method for bounding response time jitter for high pri, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and System and method for bounding response time jitter for high pri will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2135926