If write_backward attribute is set, records are written into kernel
ring buffer from end to beginning, but read from beginning to end.
To avoid 'XX out of order events recorded' warning message (timestamps
of records is in reverse order when using write_backward), suppress the
warning message if write_backward is selected by at lease one event.
Result:
Before this patch:
# perf record -m 1 -e raw_syscalls:sys_exit/overwrite/ \
-e raw_syscalls:sys_enter \
dd if=/dev/zero of=/dev/null count=300
300+0 records in
300+0 records out
153600 bytes (154 kB) copied, 0.000601617 s, 255 MB/s
[ perf record: Woken up 5 times to write data ]
Warning:
40 out of order events recorded.
[ perf record: Captured and wrote 0.096 MB perf.data (696 samples) ]
After this patch:
# perf record -m 1 -e raw_syscalls:sys_exit/overwrite/ \
-e raw_syscalls:sys_enter \
dd if=/dev/zero of=/dev/null count=300
300+0 records in
300+0 records out
153600 bytes (154 kB) copied, 0.000644873 s, 238 MB/s
[ perf record: Woken up 5 times to write data ]
[ perf record: Captured and wrote 0.096 MB perf.data (696 samples) ]
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nilay Vaish <nilayvaish@gmail.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1468485287-33422-15-git-send-email-wangnan0@huawei.com
Signed-off-by: He Kuang <hekuang@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The fprintf_sym() and fprintf_callchain() methods now allow users to
change the existing behaviour of showing "[unknown]" as the name of
unresolved symbols to instead show "[0x123456]", i.e. its address.
The current patch doesn't change tools to use this facility, the results
from 'perf trace' and 'perf script' cotinue like:
70.109 ( 0.001 ms): qemu-system-x8/10153 poll(ufds: 0x7f2d93ffe870, nfds: 1) = 0 Timeout
[unknown] (/usr/lib64/libc-2.22.so)
[unknown] (/usr/lib64/libspice-server.so.1.10.0)
[unknown] (/usr/lib64/libspice-server.so.1.10.0)
[unknown] (/usr/lib64/libspice-server.so.1.10.0)
start_thread+0xca (/usr/lib64/libpthread-2.22.so)
__clone+0x6d (/usr/lib64/libc-2.22.so)
The next patch will make 'perf trace' use the new formatting.
Suggested-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-fja1ods5vqpg42mdz09xcz3r@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Intel PT uses the time members from the perf_event_mmap_page to convert
between TSC and perf time.
Due to a lack of foresight when Intel PT was implemented, those time
members were recorded in the (implementation dependent) AUXTRACE_INFO
event, the structure of which is generally inaccessible outside of the
Intel PT decoder. However now the conversion between TSC and perf time
is needed when processing a jitdump file when Intel PT has been used for
tracing.
So add a user event to record the time members. 'perf record' will
synthesize the event if the information is available. And session
processing will put a copy of the event on the session so that tools
like 'perf inject' can easily access it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1457426324-30158-1-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
While recording guest samples in host using perf kvm record, it will
populate unprocessable sample error, though samples will be recorded
properly. While generating report using perf kvm report, no samples will
be processed and same error will populate. We have seen this behaviour
with upstream perf(4.4-rc3) on x86 and ppc64 hardware.
Reason behind this failure is, when it tries to fetch machine from
rb_tree of machines, it fails. As a part of tracing a bug, we figured
out that this code was incorrectly refactored in commit 54245fdc35
("perf session: Remove wrappers to machines__find").
This patch will change the functionality such that if it can't fetch
machine in first trial, it will create one node of machine and add that to
rb_tree. So next time when it tries to fetch same machine from rb_tree,
it won't fail. Actually it was the case before refactoring of code in
aforementioned commit.
This patch is generated from acme perf/core branch.
Below I've mention an example that demonstrate the behaviour before and
after applying patch.
Before applying patch:
[Note: One needs to run guest before recording data in host]
ravi@ravi-bangoria:~$ ./perf kvm record -a
Warning:
5903 unprocessable samples recorded.
Do you have a KVM guest running and not using 'perf kvm'?
[ perf record: Captured and wrote 1.409 MB perf.data.guest (285 samples) ]
ravi@ravi-bangoria:~$ ./perf kvm report --stdio
Warning:
5903 unprocessable samples recorded.
Do you have a KVM guest running and not using 'perf kvm'?
# To display the perf.data header info, please use --header/--header-only options.
#
# Total Lost Samples: 0
#
# Samples: 285 of event 'cycles'
# Event count (approx.): 88715406
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ......
#
# (For a higher level overview, try: perf report --sort comm,dso)
#
After applying patch:
ravi@ravi-bangoria:~$ ./perf kvm record -a
[ perf record: Captured and wrote 1.188 MB perf.data.guest (17 samples) ]
ravi@ravi-bangoria:~$ ./perf kvm report --stdio
# To display the perf.data header info, please use --header/--header-only options.
#
# Total Lost Samples: 0
#
# Samples: 17 of event 'cycles'
# Event count (approx.): 700746
#
# Overhead Command Shared Object Symbol
# ........ ....... ................ ......................
#
34.19% :5758 [unknown] [g] 0xffffffff818682ab
22.79% :5758 [unknown] [g] 0xffffffff812dc7f8
22.79% :5758 [unknown] [g] 0xffffffff818650d0
14.83% :5758 [unknown] [g] 0xffffffff8161a1b6
2.49% :5758 [unknown] [g] 0xffffffff818692bf
0.48% :5758 [unknown] [g] 0xffffffff81869253
0.05% :5758 [unknown] [g] 0xffffffff81869250
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v3.19+
Fixes: 54245fdc35 ("perf session: Remove wrappers to machines__find")
Link: http://lkml.kernel.org/r/1449471302-11283-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Jiri Olsa
Wang Nan
Arnaldo Carvalho de Melo
Ingo Molnar
Linus Torvalds
Adam Buchbinder
Milian Wolff
Adrian Hunter
Ravi Bangoria