Impact: fix stuck NMIs and non-working oprofile on certain CPUs
Resetting the counter width of the performance counters on Intel's
Core2 CPUs, breaks the delivery of NMIs, when running in x86_64 mode.
This should fix bug #12395:
http://bugzilla.kernel.org/show_bug.cgi?id=12395
Signed-off-by: Tim Blechmann <tim@klingt.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <20090303100412.GC10085@erda.amd.com>
Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: fix kernel crash
Both oprofile and perfcounters register an NMI die handler, but only one
can handle the NMI. Conveniently, oprofile unregisters it's notifier
when not actively in use, so setting it's notifier priority higher than
perfcounter's allows oprofile to borrow the NMI for the duration of it's
run. Tested/works both as module and built-in.
While testing, I found that if kerneltop was generating NMIs at very
high frequency, the kernel may panic when oprofile registered it's
handler. This turned out to be because oprofile registers it's handler
before reset_value has been allocated, so if an NMI comes in while it's
still setting up, kabOom. Rather than try more invasive changes, I
followed the lead of other places in op_model_ppro.c, and simply
returned in that highly unlikely event. (debug warnings attached)
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Impact: rename include file
We'll be providing an asm/perf_counter.h to the generic perfcounter code,
so use the already existing x86 file for this purpose and rename it.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
If oprofile statically compiled in kernel, a cpu unplug triggers
a panic in ppro_stop(), because a NULL pointer is dereferenced.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
reset_value was changed from long to u64 in commit
b991702884 (oprofile: Implement Intel
architectural perfmon support)
But dynamic allocation of this array use a wrong type (long instead of
u64)
Cc: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Fix the counter overflow check for CPUs with counter width > 32
I had a similar change in a different patch that I didn't submit
and I didn't notice the problem earlier because it was always
tested together.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Discover number of counters for all family 6 models even when not
in arch perfmon mode.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Newer Intel CPUs (Core1+) have support for architectural
events described in CPUID 0xA. See the IA32 SDM Vol3b.18 for details.
The advantage of this is that it can be done without knowing about
the specific CPU, because the CPU describes by itself what
performance events are supported. This is only a fallback
because only a limited set of 6 events are supported.
This allows to do profiling on Nehalem and on Atom systems
(later not tested)
This patch implements support for that in oprofile's Intel
Family 6 profiling module. It also has the advantage of supporting
an arbitary number of events now as reported by the CPU.
Also allow arbitary counter widths >32bit while we're at it.
Requires a patched oprofile userland to support the new
architecture.
v2: update for latest oprofile tree
remove force_arch_perfmon
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
This patch introduces multiplexing support for the Oprofile kernel
module. It basically adds a new function pointer in oprofile_operator
allowing each architecture to supply its callback to switch between
different sets of event when the timer expires. Userspace tools can
modify the time slice through /dev/oprofile/time_slice.
It also modifies the number of counters exposed to the userspace through
/dev/oprofile. For example, the number of counters for AMD CPUs are
changed to 32 and multiplexed in the sets of 4.
Signed-off-by: Jason Yeh <jason.yeh@amd.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
