This is a suggested patch to fix the bug I reported at:
http://marc.info/?l=linux-kernel&m=135033028924652&w=2
Essentially, there is a hard requirement that when perf analyzes a
trace, it must have the entire thing mmap()'d.
Therefore the scheme used on 32-bit where we have a fixed (8) number of
32MB mmaps, and cycle through them, simply does not work.
One of the reasons this requirement exists is because the iterators
maintain references to perf entry objects and those references don't
just simply go away when this mmap code decides to cycle an old mmap
area out and reuse it. At this point, those entry pointers now point to
garbage resulting in unpredictable behavior and crashes.
It is better to try to mmap() as much as we can and if we do actually
run into address space limitations, the failure of the mmap() call will
indicate that and stop processing.
I noticed that perf_session->mmap_window is set to a constant in one
location, and only used in one other location. So I got rid of it
altogether.
So we adjust the size of the mmaps[] array to the maximum we could need.
On 64-bit we only need one slot. On 32-bit we could need up to 128 (128
* 32MB == 4GB).
I've verified that this allows a large (~600MB) perf.data file to be
analyzed properly with a 32-bit perf binary, which previously was not
possible.
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20121110.141219.582924082787523608.davem@davemloft.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Make perf build for x86 once the UAPI disintegration patches for that arch
have been applied by adding the appropriate -I flags - in the right order -
and then converting some #includes that use ../.. notation to find main kernel
headerfiles to use <asm/foo.h> and <linux/foo.h> instead.
Note that -Iarch/foo/include/uapi is present _before_ -Iarch/foo/include.
This makes sure we get the userspace version of the pt_regs struct. Ideally,
we wouldn't have the latter -I flag at all, but unfortunately we want
asm/svm.h and asm/vmx.h in builtin-kvm.c and these aren't part of the UAPI -
at least not for x86. I wonder if the bits outside of the __KERNEL__ guards
*should* be transferred there.
I note also that perf seems to do its dependency handling manually by listing
all the header files it might want to use in LIB_H in the Makefile. Can this
be changed to use -MD?
Note that to do make this work, we need to export and UAPI disintegrate
linux/hw_breakpoint.h, which I think should've been exported previously so that
perf can access the bits. We have to do this in the same patch to maintain
bisectability.
Signed-off-by: David Howells <dhowells@redhat.com>
The UAPI commits forgot to test tooling builds such as tools/perf/,
and this fixes the fallout.
Manual conversion.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pevent thing is per perf.data file, so I made it stop being static
and become a perf_session member, so tools processing perf.data files
use perf_session and _there_ we read the trace events description into
session->pevent and then change everywhere to stop using that single
global pevent variable and use the per session one.
Note that it _doesn't_ fall backs to trace__event_id, as we're not
interested at all in what is present in the
/sys/kernel/debug/tracing/events in the workstation doing the analysis,
just in what is in the perf.data file.
This patch also introduces perf_session__set_tracepoints_handlers that
is the perf perf.data/session way to associate handlers to tracepoint
events by resolving their IDs using the events descriptions stored in a
perf.data file. Make 'perf sched' use it.
Reported-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Tested-by: Dmitry Antipov <dmitry.antipov@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linaro-dev@lists.linaro.org
Cc: patches@linaro.org
Link: http://lkml.kernel.org/r/20120625232016.GA28525@infradead.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf improvements from Arnaldo Carvalho de Melo:
* Replace event_name with perf_evsel__name, that handles the event
modifiers and doesn't use static variables.
* GTK browser improvements, from Namhyung Kim
* Fix possible NULL pointer deref in the TUI annotate browser, from
Samuel Liao
* Add sort by source file:line number, using addr2line.
* Allow printing histogram text snapshots at any point in top/report.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Based on Jiri's latest attempt:
https://lkml.org/lkml/2012/5/16/61
Basically, adds_features should be byte swapped assuming unsigned
longs are either 8-bytes (u64) or 4-bytes (u32).
Fixes 32-bit ppc dumping 64-bit x86 feature data:
========
captured on: Sun May 20 19:23:23 2012
hostname : nxos-vdc-dev3
os release : 3.4.0-rc7+
perf version : 3.4.rc4.137.g978da3
arch : x86_64
nrcpus online : 16
nrcpus avail : 16
cpudesc : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
cpuid : GenuineIntel,6,26,5
total memory : 24680324 kB
...
Verified 64-bit x86 can still dump feature data for 32-bit ppc.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4FBBB539.5010805@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
