The exFAT kernel driver for Linux 6.2 has received a batch of optimization patches to create files and directories faster than previous versions for SD cards or USB flash drives using the exFAT file system.

The exFAT file system is a replacement for the FAT32 file system developed by Microsoft and found widespread use throughout the electronics industry, especially SD cards, USB flash drives, digital cameras, and MP3 players. In 2019, Microsoft released the exFAT technical documentation and expressed its desire to integrate the exFAT function into the Linux kernel. In the same year, in the Linux kernel version 5.4, the exFAT file system was initially supported.

Since entering the Linux kernel, the exFAT file system has been continuously obtained fromOptimization of electronic suppliers such as Samsung and Sony, for example, in April this yearSony provides the exFAT Linux driver 73%+ performance improvement. The optimization of exFAT in Linux 6.2 also comes from Sony engineer Yuezhang Mo, mainly adding hints for empty directory entries to avoid repeatedly traversing directory entries. This improvement helps reduce CPU usage and improves performance when creating files and directories, especially on low-end processors.

The test configuration for this exFAT optimization is i.MX6Q SoC + class-4 SD card. The test results show that the file creation speed is increased by about 14% when there are few files. exFAT performance optimization can be up to 50% if creating thousands of files.

The above performance optimization is only part of the exfat optimization patch for Linux 6.2-rc1. Other optimization items, such as reducing cache size, dynamically configuring cache items, optimizing parameter settings, etc., can be optimized in exFAT Read it in the PR email.