My goal here is to be able to qualify and characterize NAND flash by running fio job files on it. The major problem with NAND is that it wears out. The most basic thing to test is how long it takes blocks to wear out with repeated program/erase cycles. Linux exposes NAND devices, among other things, with the MTD subsystem. That system allows the proper read, write and erase block sizes which vary in ways unlike normal block devices. For many MTD devices, blocks must be erased before writing them, and some have to be written in sequential order. This patch series adds - an MTD ioengine, interpreting trim as erase. - a new writetrim workload to alternate between writes and trims in a way that makes sense for devices which need to be erased before sequential writes. - a histogram counting the first trim block where an error occurred, which corresponds to block lifetime in the case of NAND. In v2, the writetrim mode was renamed to trimwrite and documentation was improved. Dan Ehrenberg (7): Allow trim on any file type Add new trimwrite rw= mode for trims preceding writes Collect a block-wise histogram of trim and write errors mtd: Add CONFIG_MTD to ./configure script mtd: Import libmtd with modifications to make it compile mtd: ioengine mtd: example job file HOWTO | 37 +- Makefile | 5 + backend.c | 5 + client.c | 4 + configure | 20 + engines/mtd.c | 209 ++++++++ examples/mtd.fio | 21 + filesetup.c | 26 +- fio.1 | 29 +- init.c | 7 + io_ddir.h | 3 + io_u.c | 25 +- iolog.c | 12 + lib/libmtd.c | 1424 +++++++++++++++++++++++++++++++++++++++++++++++++++ lib/libmtd.h | 354 +++++++++++++ lib/libmtd_common.h | 223 ++++++++ lib/libmtd_int.h | 109 ++++ lib/libmtd_legacy.c | 384 ++++++++++++++ lib/libmtd_xalloc.h | 106 ++++ options.c | 34 +- options.h | 2 + server.c | 4 + stat.c | 199 +++++++ stat.h | 27 + thread_options.h | 6 + 25 files changed, 3254 insertions(+), 21 deletions(-) create mode 100644 engines/mtd.c create mode 100644 examples/mtd.fio create mode 100644 lib/libmtd.c create mode 100644 lib/libmtd.h create mode 100644 lib/libmtd_common.h create mode 100644 lib/libmtd_int.h create mode 100644 lib/libmtd_legacy.c create mode 100644 lib/libmtd_xalloc.h -- 2.2.0.rc0.207.ga3a616c -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
