For those dealing with [1]exFAT formatted storage devices under Linux, the upcoming [2]Linux 6.15 kernel has a big optimization for yielding much faster delete performance when making use of the "discard" mount option.

The exFAT file-system updates were sent out today for the kernel driver with Linux 6.15. There are some small fixes and optimizations to this exFAT driver but most striking is the improvement to delete performance when leveraging the discard mount option.

Yuezhang Mo of Sony made the improvement to support batch discard of clusters when freeing clusters. Mo explained in that patch:

"If the discard mount option is enabled, the file's clusters are discarded when the clusters are freed. Discarding clusters one by one will significantly reduce performance. Poor performance may cause soft lockup when lots of clusters are freed.

This commit improves performance by discarding contiguous clusters in batches."

For deleting an 80G test file, on prior kernels atop an exFAT file-system it took 286 seconds while with this patch for Linux 6.15 it drops down to 1.6 seconds! It's quite an improvement for those using exFAT file-systems with the discard mount option:

The exFAT patches for Linux 6.15 can be found via [3]this pull request .



[1] https://www.phoronix.com/search/exFAT

[2] https://www.phoronix.com/search/Linux+6.15

[3] https://lore.kernel.org/lkml/CAKYAXd_E0eM8dfoU1HVQ+DW4YKMsrzfJbGTsQELjfy=R+omndw@mail.gmail.com/