The Unsorted Block Images "UBI" layer in the Linux kernel for NAND flash memory tracking and wear leveling finally has the notion of per-device wear-leveling thresholds.

Merged for Linux 7.3 is UBI support for per-device wear-leveling thresholds. Until now the wear-leveling threshold for UBI has been a compile-time constant for all UBI devices on the system. Ran Hongyun of Huawei finally addressed this obstacle with per-device threshold support.

For systems with multiple NAND flashes with differing erase lifetimes, a new "wl_threshold" option for the ubi.mtd module parameter can be set at boot-time for specifying the wear-leveling threshold for each of the NAND flashes on the system. Or a value of zero to revert back to using the compile-time constant.

One would have thought per-device wear-leveling thresholds for UBI devices would have been supported years ago, but in any event it's now in place with Linux 7.3. The code was merged on Friday via [1]this pull request .



[1] https://lore.kernel.org/lkml/7545938.rdbgypaU67@nailgun/