perf/x86/intel/rapl: Make package handling more robust

The package management code in RAPL relies on package mapping being
available before a CPU is started. This changed with:

  9d85eb9119f4 ("x86/smpboot: Make logical package management more robust")

because the ACPI/BIOS information turned out to be unreliable, but that
left RAPL in broken state. This was not noticed because on a regular boot
all CPUs are online before RAPL is initialized.

A possible fix would be to reintroduce the mess which allocates a package
data structure in CPU prepare and when it turns out to already exist in
starting throw it away later in the CPU online callback. But that's a
horrible hack and not required at all because RAPL becomes functional for
perf only in the CPU online callback. That's correct because user space is
not yet informed about the CPU being onlined, so nothing caan rely on RAPL
being available on that particular CPU.

Move the allocation to the CPU online callback and simplify the hotplug
handling. At this point the package mapping is established and correct.

This also adds a missing check for available package data in the
event_init() function.

Reported-by: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 9d85eb9119f4 ("x86/smpboot: Make logical package management more robust")
Link: http://lkml.kernel.org/r/20170131230141.212593966@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

path: root/.authors.aux

The following people have provided helpful bug reports, suggestions or have
otherwise provided valuable contributions to the project:

 * Christoph Jaeger <email@christophjaeger.info>
 * Dan Horák <dan@danny.cz>
 * Dennis Gilmore <dennis@ausil.us>
 * Doug Burks <doug.burks@gmail.com>
 * Emmanuel Roullit <emmanuel.roullit@gmail.com>
 * Herbert Haas <herbert@perihel.at>
 * Jim Binder <jbinder6342@gmail.com>
 * Markus Kötter <nepenthesdev@gmail.com>
 * Ronald W. Henderson <rwhalb@nycap.rr.com>
 * Scott Moeller <electronjoe@gmail.com>
 * Sibir Chakraborty <sibir.chakraborty@gmail.com>
 * Stefan Seering <sseerin@imn.htwk-leipzig.de>
 * Ulrich Weber <uweber@astaro.com>

Special thanks to some of our sponsors:

 * Deutsche Flugsicherung GmbH
 * ETH Zurich, Communications Systems Group
 * Max Planck Institute for Human Cognitive and Brain Sciences
 * Team Cymru

Notes:

Note that we have taken over the maintenance and further development of Herbert
Haas' mausezahn [ˈmauzəˌtsa:n] utility after he passed away in 2011. There were
no Git commit statistics available from the import of his project. The project
is currently in a staging area, but will be fully integrated soon. (*)

Want to join the core team? Submit enough great patches over a long time,
implement what's on the TODO file and show an ongoing, active interest in
supporting netsniff-ng. What's in it for you? If you ever come to Switzerland,
you get a free beer on Daniel and you can meet some great people involved in
this project. ;)