Commit 9317f72d authored by Jim Harris's avatar Jim Harris Committed by Tomasz Zawadzki
Browse files

fio_plugin: clarify thread=1 



There was some confusion from a user on whether thread=1
means only one thread is supported.  So add some extra
documentation around this section to clarify this a bit
more, since the option is a bit confusing.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Ibcccd1759180e2e6c47e736d94ffbeafc405f7bb
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/5995


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Reviewed-by: default avatar <dongx.yi@intel.com>
Community-CI: Mellanox Build Bot
parent 1d6ccec9

examples/bdev/fio_plugin/README.md

+4 −2
Original line number Diff line number Diff line
@@ -60,8 +60,10 @@ Or for NVMe devices: 


    filename=Nvme0n1



Currently the SPDK fio plugin is limited to the thread usage model, so fio jobs must also specify thread=1

when using the SPDK fio plugin.

fio by default forks a separate process for every job. It also supports just spawning a separate

thread in the same process for every job. The SPDK fio plugin is limited to this latter thread

usage model, so fio jobs must also specify thread=1 when using the SPDK fio plugin. The SPDK fio

plugin supports multiple threads - in this case, the "1" just means "use thread mode".



fio also currently has a race condition on shutdown if dynamically loading the ioengine by specifying the

engine's full path via the ioengine parameter - LD_PRELOAD is recommended to avoid this race condition.

examples/nvme/fio_plugin/README.md

+4 −2
Original line number Diff line number Diff line
@@ -56,8 +56,10 @@ and instead only use '.'. This is a limitation in fio - it splits filenames on 
':'. Also, the NVMe namespaces start at 1, not 0, and the namespace must be

specified at the end of the string.



Currently the SPDK fio plugin is limited to the thread usage model, so fio jobs must also specify thread=1

when using the SPDK fio plugin.

fio by default forks a separate process for every job. It also supports just spawning a separate

thread in the same process for every job. The SPDK fio plugin is limited to this latter thread

usage model, so fio jobs must also specify thread=1 when using the SPDK fio plugin. The SPDK fio

plugin supports multiple threads - in this case, the "1" just means "use thread mode".



fio also currently has a race condition on shutdown if dynamically loading the ioengine by specifying the

engine's full path via the ioengine parameter - LD_PRELOAD is recommended to avoid this race condition.