Policy driven IO scheduler to improve write IO performance in hybrid storage systems

A non-transitory machine-readable medium storing instructions which, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving a plurality of input/output (IO) request transactions at the storage system having a plurality of storage devices, the IO request transactions including at least a read and a write IO request transactions;
• for each of the plurality of IO request transactions,
• determining a plurality of child IO requests required to complete the IO request transaction, wherein the child IO requests comprise a write child IO request and a read child IO request;
• and
• tagging associated child IO requests with a tag identifier uniquely identifying the IO request transaction so the child IO requests associated with the IO request transaction are identified and grouped by the tag identifier unique to the IO request transaction;
• dynamically tracking how many child IO requests of the associated child IO requests are completed;
• prioritizing the plurality of IO request transactions based on a service priority level and completeness of each of the IO request transactions dynamically determined according to the dynamically tracking at a point in time while the child IO requests of the IO request transactions are being serviced;
• and
• servicing the child IO requests of the IO request transactions according to a prioritized order to reduce a time to complete the IO request transactions.

A data processing system, comprising:

• a processor;
• and
• a memory couple to the process to store instructions, which when executed by the
• processor, cause the processor to perform operations, the operations include
• receiving a plurality of input/output (IO) request transactions at the storage system having a plurality of storage devices, the IO request transactions including at least a read and a write IO request transactions;
• for each of the plurality of IO request transactions,
• determining a plurality of child IO requests required to complete the IO request transaction,
• wherein the child IO requests comprise a write child IO request and a read child IO request;
• and
• tagging associated child IO requests with a tag identifier uniquely identifying the IO request transaction so the child IO requests associated with the IO request transaction are identified and grouped by the tag identifier unique to the IO request transaction;
• dynamically tracking how many child IO requests of the associated child IO requests are completed;
• prioritizing the plurality of IO request transactions based on a service priority level and completeness of each of the IO request transactions dynamically determined according to the dynamically tracking at a point in time while the child IO requests of the IO request transactions are being serviced;
• and
• servicing the child IO requests of the IO request transactions according to a prioritized order to reduce a time to complete the IO request transactions.