Storage device supporting real-time processing and method of operating the same
A storage device includes a nonvolatile memory device and a storage controller configured to control the nonvolatile memory device under control of a plurality of hosts. The storage controller includes a plurality of physical functions, respectively corresponding to the plurality of hosts, and a real-time manager configured to control the plurality of physical functions based on real-time information of a real-time command when the real-time command is issued from at least one host among the plurality of hosts.
1 . A storage device, comprising:
a nonvolatile memory device; and
a storage controller configured to control the nonvolatile memory device under control of a plurality of hosts,
wherein
the storage controller comprises:
a plurality of physical functions respectively corresponding to the plurality of hosts; and
a real-time manager configured to control the plurality of physical functions based on real-time information of a real-time command when the real-time command is issued from at least one host among the plurality of hosts,
wherein the real-time information includes a real-time limit obtained from (i) a real-time information field in the real-time command that includes the real-time limit indicating a time from a time point at which the real-time command is written in a submission queue to a time point at which a response corresponding to the real-time command is written in a completion queue, or (ii) a real-time setting table managed by the storage device and including a plurality of real-time limits respectively matching the plurality of physical functions.
2 . The storage device of claim 1 , wherein
the real-time manager selects a physical function corresponding to a host that issued the real-time command prior to a physical function corresponding to a host that issued a general command, among the plurality of physical functions.
3 . The storage device of claim 2 , wherein
the real-time manager selects the physical function corresponding to the host that issued the real-time command, among the plurality of physical functions, based on a virtual time stamp (VTS) table, and
the VTS table comprises:
a plurality of weights respectively corresponding to the plurality of physical functions;
a plurality of VTS values, respectively corresponding to the plurality of physical functions, and set based on input/output (IO) throughput and a weight of each of the plurality of physical functions; and
a plurality of real-time flags, respectively corresponding to the plurality of physical functions, and indicating whether real-time commands of the plurality of physical functions match each other.
4 . The storage device of claim 3 , wherein
the real-time manager comprises:
a VTS manager configured to manage the VTS table; and
a command scheduler configured to select a physical function to process a command, from among the plurality of physical functions,
wherein the VTS manager enables a real-time flag of a physical function corresponding to the host that issued the real-time command, among the plurality of real-time flags of the VTS table, and
the command scheduler selects a physical function corresponding to the host that issued the real-time command, based on the enabled real-time flag, from among the plurality of physical functions.
5 . The storage device of claim 3 , wherein
the real-time manager comprises:
a VTS manager configured to manage the VTS table; and
a command scheduler configured to select a physical function to process a command, from among the plurality of physical functions,
wherein the VTS manager adjusts a weight of a physical function corresponding to the host that issued the real-time command, among the plurality of weights of the VTS table.
6 . The storage device of claim 5 , wherein
the VTS manager adjusts a weight to decrease a VTS value of a physical function corresponding to the host that issued the real-time command, among the plurality of VTS values,
wherein the command scheduler selects a physical function corresponding to a smallest VTS value, among the plurality of VTS values.
7 . The storage device of claim 1 , wherein
the real-time manager determines a number of tokens to be distributed to each of the plurality of physical functions, based on the real-time information.
8 . The storage device of claim 7 , wherein
the number of tokens distributed to a physical function corresponding to the host that issued the real-time command is larger than the number of tokens distributed to a physical function corresponding to a host that did not issue the real-time command.
9 . The storage device of claim 7 , wherein
the real-time manager adjusts the number of tokens distributed to each of the plurality of physical functions based on a state of a completion queue corresponding to each of the plurality of hosts.
10 . The storage device of claim 9 , wherein
the real-time manager deducts the number of tokens distributed to the physical function corresponding to the host that issued the real-time command when a number of responses accumulated in a completion queue of the host that issued the real-time command is larger than or equal to a reference number.
11 . The storage device of claim 1 , wherein
the real-time manager comprises:
a real-time information (RTI) checker configured to check the real-time information; and
a command scheduler configured to select a physical function to process a command, based on the real-time information, from among the plurality of physical functions,
wherein the RTI checker obtains the real-time information through the real-time information field included in the real-time command.
12 . The storage device of claim 11 , wherein
the real-time information further comprises an SQ time,
and
the SQ time indicates the time point at which the real-time command is written in the submission queue.
13 . The storage device of claim 1 , wherein
the real-time manager comprises:
a real-time information (RTI) checker configured to check the real-time information of the real-time command; and
a command scheduler configured to select a physical function to process a command, based on the real-time information, from among the plurality of physical functions,
wherein the RTI checker obtains the real-time information through the real-time setting table managed by the storage device.
14 . The storage device of claim 13 , wherein
the real-time setting table comprises:
the plurality of physical functions, respectively matching the plurality of hosts;
a plurality of automotive safety integrity level (ASIL) grades, respectively matching the plurality of physical functions; and
a plurality of real-time limits, respectively matching the plurality of physical functions,
wherein each of the plurality of real-time limits is set based on a corresponding ASIL grade, among the plurality of ASIL grades.
15 . The storage device of claim 1 , wherein
the real-time manager determines a fetch timing for the real-time command based on the real-time information.
16 . The storage device of claim 15 , wherein
the real-time manager fetches the real-time command faster as the real-time limit corresponding to the real-time command becomes shorter.
17 . A method of operating a storage device comprising a plurality of physical functions, respectively corresponding to a plurality of hosts, the method comprising:
obtaining real-time information on a real-time command issued by at least one host among the plurality of hosts;
determining a performance of a physical function corresponding to the real-time command, among the plurality of physical functions, based on the real-time information; and
fetching the real-time command and processing the fetched real-time command,
wherein the real-time information comprises a real-time limit, and the fetching is conducted faster as the real-time limit corresponding to the real-time command becomes shorter.
18 . The method of claim 17 , wherein
determining the performance of the physical function corresponding to the real-time command comprises:
selecting a physical function corresponding to a host that issued the real-time command prior to a physical function corresponding to a host that did not issue the real-time command;
distributing a larger number of tokens to the physical function corresponding to the host that issued the real-time command than to the physical function corresponding to the host that did not issue the real-time command; and
adjusting the number of tokens distributed to the physical function corresponding to the host that issued the real-time command, based on a state of a completion queue of the host that issued the real-time command.
19 . The method of claim 17 , wherein
the real-time information is obtained from one of a real-time information field included in the real-time command and a real-time setting table managed by the storage device.
20 . A storage controller that controls a nonvolatile memory device, the storage controller comprising:
a nonvolatile memory interface circuit for communicating with the nonvolatile memory device;
a plurality of physical functions, respectively corresponding to a plurality of hosts, and independently controlling the nonvolatile memory device based on a request of each of the plurality of hosts; and
a real-time manager configured to perform a performance control operation on the plurality of physical functions based on real-time information of a real-time command when the real-time command is issued from at least one host among the plurality of hosts,
wherein the real-time information includes a real-time limit obtained from (i) a real-time information field in the real-time command that includes the real-time limit indicating a time from a time point at which the real-time command is written in a submission queue to a time point at which a response corresponding to the real-time command is written in a completion queue, or (ii) a real-time setting table managed by a storage device and including a plurality of real-time limits respectively matching the plurality of physical functions.