tracing: Fix hwlat kthread migration

The hwlat tracer creates a kernel thread at start of the tracer. It is
pinned to a single CPU and will move to the next CPU after each period of
running. If the user modifies the migration thread's affinity, it will not
change after that happens.

The original code created the thread at the first instance it was called,
but later was changed to destroy the thread after the tracer was finished,
and would not be created until the next instance of the tracer was
established. The code that initialized the affinity was only called on the
initial instantiation of the tracer. After that, it was not initialized, and
the previous affinity did not match the current newly created one, making
it appear that the user modified the thread's affinity when it did not, and
the thread failed to migrate again.

Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

path: root/net/switchdev/Kconfig

#
# Configuration for Switch device support
#

config NET_SWITCHDEV
	bool "Switch (and switch-ish) device support"
	depends on INET
	---help---
	  This module provides glue between core networking code and device
	  drivers in order to support hardware switch chips in very generic
	  meaning of the word "switch". This include devices supporting L2/L3 but
	  also various flow offloading chips, including switches embedded into
	  SR-IOV NICs.