Automatically preventing large block writes from starving small block writes in a storage device

1. A computer program product comprising a non-transitory computer readable storage medium having a computer readable program stored therein, wherein the computer readable program, when executed on a processor of a storage device, causes the processor to:

configure a write buffer memory with a plurality of write buffer portions, wherein each write buffer portion is dedicated to a predetermined block size category within a plurality of block size categories;

for each write operation from an initiator, determine a block size category of the write operation;

perform each write operation by writing to a write buffer portion within the plurality of write buffer portions corresponding to the block size category of the write operation;

determine a bandwidth percentage for a first block size category;

complete writes of only the first block size category until the bandwidth percentage is reached; and

complete a write of the second block size category responsive to the bandwidth percentage being reached.

2. The computer program product of claim 1 , wherein the computer readable program further causes the processor to:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, update a blocking delay value for the block size category of the given write operation.

3. The computer program product of claim 2 , wherein the computer readable program further causes the processor to:

adjust sizes of the plurality of write buffer portions based on blocking delay values of the block size categories.

4. The computer program product of claim 1 , wherein configuring the write buffer memory comprises configuring a shared buffer portion, wherein the shared buffer portion stores writes of all block size categories, wherein the computer readable program further causes the processor to:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, perform the given write operation by writing to the shared buffer portion.

5. The computer program product of claim 4 , wherein the computer readable program further causes the processor to:

responsive to the shared buffer portion being full, update a blocking delay value for the block size category of the given write operation.

6. The computer program product of claim 4 , wherein the computer readable program further causes the processor to:

for each write operation from the initiator, increment a counter corresponding to the block size category of the write operation;

responsive to expiration of a time interval, determine whether a given counter corresponding to a given block size category is less than a predetermined threshold; and

responsive to the given counter being less than the predetermined threshold, convert the write buffer portion corresponding to the given block size category to a shared buffer portion.

7. The computer program product of claim 6 , wherein the computer readable program further causes the processor to:

restart the time interval;

for each write operation from the initiator, increment a counter corresponding to the block size category of the write operation;

responsive to expiration of the time interval, determine whether the given counter is greater than the predetermined threshold; and

responsive to the given counter being greater than the predetermined threshold, reconfigure the write buffer portion corresponding to the given block size.

8. The computer program product of claim 1 , wherein the computer readable program is stored in a computer readable storage medium in a data processing system and wherein the computer readable program was downloaded over a network from a remote data processing system.

9. The computer program product of claim 1 , wherein the computer readable program is stored in a computer readable storage medium in a server data processing system and wherein the computer readable program is downloaded over a network to a remote data processing system for use in a computer readable storage medium with the remote system.

10. A method, in a storage device, for performing a write operation, the method comprising:

configuring a write buffer memory with a plurality of write buffer portions, wherein each write buffer portion is dedicated to a predetermined block size category within a plurality of block size categories;

for each write operation from an initiator, determining a block size category of the write operation;

performing each write operation by writing to a write buffer portion within the plurality of write buffer portions corresponding to the block size category of the write operation;

determining a bandwidth percentage for a first block size category;

completing writes of only the first block size category until the bandwidth percentage is reached; and

completing a write of the second block size category responsive to the bandwidth percentage being reached.

11. The method of claim 10 , further comprising:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, updating a blocking delay value for the block size category of the given write operation.

12. The method of claim 11 , further comprising:

adjusting sizes of the plurality of write buffer portions based on blocking delay values of the block size categories.

13. The method of claim 10 , wherein configuring the write buffer memory comprises configuring a shared buffer portion, wherein the shared buffer portion stores writes of all block size categories, the method further comprising:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, performing the given write operation by writing to the shared buffer portion.

14. The method of claim 13 , further comprising:

responsive to the shared buffer portion being full, updating a blocking delay value for the block size category of the given write operation.

15. The method of claim 13 , further comprising:

for each write operation from the initiator, incrementing a counter corresponding to the block size category of the write operation;

responsive to expiration of a time interval, determining whether a given counter corresponding to a given block size category is less than a predetermined threshold; and

responsive to the given counter being less than the predetermined threshold, converting the write buffer portion corresponding to the given block size category to a shared buffer portion.

16. The method of claim 15 , further comprising:

restarting the time interval;

for each write operation from the initiator, incrementing a counter corresponding to the block size category of the write operation;

responsive to expiration of the time interval, determining whether the given counter is greater than the predetermined threshold; and

responsive to the given counter being greater than the predetermined threshold, reconfiguring the write buffer portion corresponding to the given block size.

17. An apparatus, comprising:

a processor; and

a memory coupled to the processor, wherein the memory comprises instructions which, when executed by the processor, cause the processor to:

configure a write buffer memory with a plurality of write buffer portions, wherein each write buffer portion is dedicated to a predetermined block size category within a plurality of block size categories;

for each write operation from an initiator, determine a block size category of the write operation;

perform each write operation by writing to a write buffer portion within the plurality of write buffer portions corresponding to the block size category of the write operation;

determine a bandwidth percentage for a first block size category;

complete writes of only the first block size category until the bandwidth percentage is reached; and

complete a write of the second block size category responsive to the bandwidth percentage being reached.

18. The apparatus of claim 17 , wherein the instructions further cause the processor to:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, update a blocking delay value for the block size category of the given write operation; and

adjust sizes of the plurality of write of buffer portions based on blocking delay values of the block size categories.

19. The apparatus of claim 17 , wherein configuring the write buffer memory comprises configuring a shared buffer portion, wherein the shared buffer portion stores writes of all block size categories, wherein the instructions further cause the processor to:

responsive to a write buffer portion corresponding to a block size category of a given write operation being full, perform the given write operation by writing to the shared buffer portion.

20. The apparatus of claim 19 , wherein the instructions further cause the processor to:

responsive to the shared buffer portion being full, update a blocking delay value for the block size category of the given write operation.

21. The apparatus of claim 19 , wherein the instructions further cause the processor to:

for each write operation from the initiator, incrementing a counter corresponding to block size category of the write operation;

responsive to expiration of a time interval, determining whether a given counter corresponding to a given block size category is less than a predetermined threshold; and responsive to the given counter being less than the predetermined threshold, converting the write buffer portion corresponding to the given block size category to a shared buffer portion.

22. The apparatus of claim 21 , wherein the instructions further cause the processor to:

restart the time interval;

for each write operation from the initiator, increment a counter corresponding to the block size category of the write operation;

responsive to expiration of the time interval, determine whether the given counter is greater than the predetermined threshold; and

responsive to the given counter being greater than the predetermined threshold, reconfigure the write buffer portion corresponding to the given block size.