US 11,942,110 B2
Magnetic disk device and command processing method
Takashi Fujinami, Fujisawa Kanagawa (JP); Noriyuki Satou, Kamakura Kanagawa (JP); and Takashi Onoda, Yokohama Kanagawa (JP)
Assigned to KABUSHIKI KAISHA TOSHIBA, Tokyo (JP); and TOSHIBA ELECTRONIC DEVICES & STORAGE CORPORATION, Tokyo (JP)
Filed by Kabushiki Kaisha Toshiba, Tokyo (JP); and Toshiba Electronic Devices & Storage Corporation, Tokyo (JP)
Filed on Mar. 9, 2023, as Appl. No. 18/119,749.
Claims priority of application No. 2022-138628 (JP), filed on Aug. 31, 2022.
Prior Publication US 2024/0071420 A1, Feb. 29, 2024
Int. Cl. G11B 5/55 (2006.01); G11B 19/02 (2006.01)
CPC G11B 19/02 (2013.01) 11 Claims
OG exemplary drawing
 
1. A magnetic disk device comprising:
a disk;
a head writing data to the disk and reading data from the disk;
a command queue temporarily storing one or more commands received;
a command residence time calculation unit calculating a residence time of each of the commands in the command queue;
a command information calculation unit calculating the number of the commands in the command queue, and a ratio of read commands to write commands in the command queue;
a limit time determination unit obtaining a latency limit time corresponding to the number of commands and the ratio, from among a plurality of latency limit times in a latency limit time determination table; and
a command selection processing unit selecting a command to be executed, by considering the latency limit time obtained by the limit time determination unit.