Hi, Users that have custom firmware SSDs, may choose to expose their flash directly. This allows the host to control logical to physical address mappings, garbage collection strategy, wear-leveling, and so on. This is beneficial when you either want to strip the cost of a costly controller or want detailed control over an SSD. Such as implementing key-value stores, object-stored, atomic I/Os, etc. LightNVM implements the host-side core. It supports two modes. Users that doesn't have hardware available and want to emulate an SSD, and users with a physical SSD, that has a LightNVM compatible firmware. The behavior of the core can be exposed through the various components that make up an FTL. Thus, it is not single implementation, but instead possible to mix the best algorithms for the user-space application workloads. Currently, LightNVM implements a page-based FTL, cost-based GC and simple wear-leveling. Additionally, it allows simulation of flash timings when hardware isn't available. There's work on getting it to the OpenSSD platform with a custom firmware and getting it stable for broad use. There is still much work to do. I'm looking for feedback on the approach, dm integration, and more. Any feedback is greatly appreciated. A presentation was given at the recent Non-Volatile Memory Workshop (NVMW) workshop. Slides are available at: http://bjorling.me/NVMW2014-LightNVM.pdf Major todo's: * Patch has TODO and FIXME in places that needs to be cleaned. * LightNVM compatible firmware for the OpenSSD platform and integration. * Performance regressions during GC. * Durability during power failure. Thanks, Matias Matias Bjørling (1): dm-lightnvm: An open FTL for open firmware SSDs drivers/md/Kconfig | 1 + drivers/md/Makefile | 1 + drivers/md/lightnvm/Kconfig | 14 + drivers/md/lightnvm/Makefile | 1 + drivers/md/lightnvm/core.c | 705 +++++++++++++++++++++++++++++++++++++++++ drivers/md/lightnvm/gc.c | 208 ++++++++++++ drivers/md/lightnvm/lightnvm.c | 589 ++++++++++++++++++++++++++++++++++ drivers/md/lightnvm/lightnvm.h | 592 ++++++++++++++++++++++++++++++++++ drivers/md/lightnvm/reg.c | 41 +++ 9 files changed, 2152 insertions(+) create mode 100644 drivers/md/lightnvm/Kconfig create mode 100644 drivers/md/lightnvm/Makefile create mode 100644 drivers/md/lightnvm/core.c create mode 100644 drivers/md/lightnvm/gc.c create mode 100644 drivers/md/lightnvm/lightnvm.c create mode 100644 drivers/md/lightnvm/lightnvm.h create mode 100644 drivers/md/lightnvm/reg.c -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
