It is quite legitimate for CPUs to be numbered sparsely, meaning
that it possible for an online CPU to have a number which is
greater than the total count of possible CPUs.
Currently find_get_context() has a sanity check on the cpu
number where it checks it against num_possible_cpus(). This
test can fail for a legitimate cpu number if the
cpu_possible_mask is sparsely populated.
This fixes the problem by checking the CPU number against
nr_cpumask_bits instead, since that is the appropriate check to
ensure that the cpu number is same to pass to cpu_isset()
subsequently.
Reported-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Michael Neuling <mikey@neuling.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@kernel.org>
LKML-Reference: <20091215084032.GA18661@brick.ozlabs.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Allow scripts to be recorded/executed by simply specifying the
script root name (the script name minus extension) along with
'record' or 'report' to 'perf trace'.
The script names shown by 'perf trace -l' can be directly used
to run the command-line contained within the corresponding
'-record' and '-report' versions of scripts in the scripts/*/bin
directories.
For example, to record the trace data needed to run the
wakeup-latency.pl script, the user can easily find the name of
the corresponding script from the script list and invoke it
using 'perf trace record', without having to remember the
details of how to do the same thing using the lower-level perf
trace command-line options:
root@tropicana:~# perf trace -l
List of available trace scripts:
workqueue-stats workqueue stats (ins/exe/create/destroy)
wakeup-latency system-wide min/max/avg wakeup latency
rw-by-file <comm> r/w activity for a program, by file
check-perf-trace useless but exhaustive test script
rw-by-pid system-wide r/w activity
root@tropicana:~# perf trace record wakeup-latency
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.296 MB perf.data (~12931
samples) ]
To run the wakeup-latency.pl script using the captured data,
change 'record' to 'report' in the command-line:
root@tropicana:~# perf trace report wakeup-latency
wakeup_latency stats:
total_wakeups: 65
avg_wakeup_latency (ns): 22417
min_wakeup_latency (ns): 3470
max_wakeup_latency (ns): 223311
perf trace Perl script stopped
If the script takes options, thay can be simply added to the end
of the 'report' invocation:
root@tropicana:~# perf trace record rw-by-file
^C[ perf record: Woken up 2 times to write data ]
[ perf record: Captured and wrote 0.782 MB perf.data (~34171
samples) ]
root@tropicana:~# perf trace report rw-by-file perf
file read counts for perf:
fd # reads bytes_requested
------ ---------- -----------
122 1934 1980416
120 1 32
file write counts for perf:
fd # writes bytes_written
------ ---------- -----------
3 4006 280568
perf trace Perl script stopped
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1260867220-15699-6-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Lists the available perf trace scripts, one per line e.g.:
root@tropicana:~# perf trace -l
List of available trace scripts:
workqueue-stats workqueue stats (ins/exe/create/destroy)
wakeup-latency system-wide min/max/avg wakeup latency
rw-by-file <comm> r/w activity for a program, by file
check-perf-trace useless but exhaustive test script
rw-by-pid system-wide r/w activity
To be consistent with the other listing options in perf, the
current latency trace option was changed to '-L', and '-l' is
now used to access the script listing as:
To create the list, it searches each scripts/*/bin directory for
files ending with "-report" and reads information found in
certain comment lines contained in those shell scripts:
- if the comment line starts with "description:", the rest of the
line is used as a 'half-line' description. To keep each line in
the list to a single line, the description should be limited to 40
characters (the rest of the line contains the script name and
args)
- if the comment line starts with "args:", the rest of the line
names the args the script supports. Required args should be
surrounded by <> brackets, optional args by [] brackets.
The current scripts in scripts/perl/bin have also been updated
with description: and args: comments.
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1260867220-15699-5-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
One oversight of the original scripting_ops patch was a lack of
support for passing args to handler scripts. This adds
argc/argv to the start_script() scripting_op, and changes the
rw-by-file script to take 'comm' arg rather than the 'perf'
value currently hard-coded. It also takes the opportunity to do
some related minor cleanup.
Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1260867220-15699-2-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There is still some more work to do to disentangle map creation
from DSO loading, but this happens only for the kernel, and for
the early adopters of perf diff, where this disentanglement
matters most, we'll be testing different kernels, so no problem
here.
Further clarification: right now we create the kernel maps for
the various modules and discontiguous kernel text maps when
loading the DSO, we should do it as a two step process, first
creating the maps, for multiple mappings with the same DSO
store, then doing the dso load just once, for the first hit on
one of the maps sharing this DSO backing store.
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260741029-4430-6-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Arnaldo Carvalho de Melo
Ingo Molnar
Paul Mackerras
Tom Zanussi
Frederic Weisbecker
David Miller