Settings subsystem is storing the name ID and the linked list node ID
with only one bit difference at BIT(0).
Settings subsystem is also storing the name ID and the data ID in two
different ZMS entries at an exact offset of ZMS_DATA_ID_OFFSET.
Using the regular lookup function could result in many cache misses.
Therefore, to assure the least number of collisions in the lookup cache,
the BIT(0) of the hash indicates whether the given ZMS ID represents a
linked list entry or not, the BIT(1) indicates whether the ZMS ID is a
name or data and the remaining bits of the hash are set to a truncated
part of the original hash generated by Settings.
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
When the CONFIG_ZMS_NO_DOUBLE_WRITE is not enabled there is no need to
search in the cache for matching ID
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
When power cuts during a GC operation, the sector is erased again in the
next reboot cycle and the cycle_cnt of the empty ATE is incremented.
If the same power cut happens 255 times in a row, the empty ATE cycle_cnt
will become equal to the close ATE which causes a memory corruption.
Fix this by checking the close ATE cycle_cnt before incrementing the
empty ATE cycle_cnt.
Fixes: #84874
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
Previously, when detecting the GC_done ATE the gc_done_marker boolean
variable was not set.
Fix this by setting it to true if the GC_done ATE is found.
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
Add missing Copyright from derived files and fix the Copyright year for
some files to keep the original Copyright notice
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
This resolves some addressed comments in this PR zephyrproject-rtos#77930
as well as this PR zephyrproject-rtos#80407
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
when performing a write ZMS checks if the data exists in the storage to
avoid double writing the same data and save some memory cycle life time.
However this downgrades the write performance.
Enable this feature only when CONFIG_ZMS_NO_DOUBLE_WRITE is enabled.
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
This resolves some addressed comments in this PR
https://github.com/zephyrproject-rtos/zephyr/pull/77930
It adds as well a section in the documentation about some
recommendations to increase ZMS performance.
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
ZMS is the abreviation of Zephyr Memory Storage.
It is a storage developed to target especially the non erasable devices.
The new memory storage system inherit from the NVS storage multiple
features and introduce new ones :
* Inherited features :
- light key-value based storage
- cache for entries
- Wear Leveling of flash memory
- Resilience to power failures
* New features :
- cycle counter for non erasable devices (instead of erase emulation)
- Keys up to 32-bit
- Built-in support of CRC32 for data
- Small size data (<= 8 bytes) integrated within entries
Signed-off-by: Riadh Ghaddab <rghaddab@baylibre.com>
