config DCB
bool "Data Center Bridging support"
default n
---help---
This enables support for configuring Data Center Bridging (DCB)
features on DCB capable Ethernet adapters via rtnetlink. Say 'Y'
if you have a DCB capable Ethernet adapter which supports this
interface and you are connected to a DCB capable switch.
DCB is a collection of Ethernet enhancements which allow DCB capable
NICs and switches to support network traffic with differing
requirements (highly reliable, no drops vs. best effort vs. low
latency) to co-exist on Ethernet.
DCB features include:
Enhanced Transmission Selection (aka Priority Grouping) - provides a
framework for assigning bandwidth guarantees to traffic classes.
Priority-based Flow Control (PFC) - a MAC control pause frame which
works at the granularity of the 802.1p priority instead of the
link (802.3x).
If unsure, say N.
' value='79c6f448c8b79c321e4a1f31f98194e4f6b6cae7'/>
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>