Squash changes for _bdevperf_construct_targets() and
bdevperf_free_targets() into a single patch to shrink the
patch series to reduce the burden of reviewers.
The pupose of the whole patch series is to move io_target from
core based to I/O channel based, and create SPDK thread per I/O channel.
It was not possible to create SPDK thread per core and then associate
target group with I/O channel as long as I tried.
So this patch moves io_target from core based to I/O channel based.
The later patch will create SPDK thread per I/O channel.
Each core has default reactor thread for now and so we can use
spdk_for_each_channel() even when we do not create and destroy SPDK
thread per target group yet.
The following is the detailed explanation:
_bdevperf_construct_targets():
Add a context for _bdevperf_construct_targets() to use
spdk_for_each_channel().
If g_every_core_for_each_bdev is false, set the target group to the
context and create target only on the group which matches the passed
group. If g_every_core_for_each_bdev is true, create target on all
groups.
Only the master thread can increment g_target_count. Hence hold
created number of targets temporary on the context and add it at
completion.
As a result of these changes, spdk_bdev_open() is called on the
thread which runs I/O to the bdev.
Hence bdevperf_target_gone() doesn't use message passing, and
bdevperf_complete() calls spdk_bdev_close() before sending
message to the master thread. Additionally, unregister pollers
directly in bdevperf_target_gone().
These changes also fix the potential issue that spdk_bdev_close()
would be called on the wrong thread if spdk_bdev_get_io_channel()
fails in bdevperf_submit_on_group().
bdevperf_free_targets():
Free each target on the thread which created it by using
spdk_for_each_channel().
This will make possible for us to use spdk_for_each_channel() for
performance dump even for shutdown case because
spdk_for_each_channel() is serialized if it is called on the same
thread.
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: I4fcdb1024adf4704d3c59215da5669dfdc6cca1b
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/641
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
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