When the kernel allows tweaking perf_event_max_stack and the event being
setup has PERF_SAMPLE_CALLCHAIN in its perf_event_attr.sample_type, tell
the user that tweaking /proc/sys/kernel/perf_event_max_stack may solve
the problem.
Before:
# echo 32000 > /proc/sys/kernel/perf_event_max_stack
# perf record -g usleep 1
Error:
The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles:ppp).
/bin/dmesg may provide additional information.
No CONFIG_PERF_EVENTS=y kernel support configured?
#
After:
# echo 64000 > /proc/sys/kernel/perf_event_max_stack
# perf record -g usleep 1
Error:
Not enough memory to setup event with callchain.
Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack
Hint: Current value: 64000
#
Suggested-by: David Ahern <dsahern@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ebv0orelj1s1ye857vhb82ov@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull RCU updates from Paul E. McKenney:
* Documentation updates, including fixes to the design-level
requirements documentation and a fixed version of the design-level
data-structure documentation. These fixes include removing
cartoons and getting rid of the html/htmlx duplication.
* Further improvements to the new-age expedited grace periods.
* Miscellaneous fixes.
* Torture-test changes, including a new rcuperf module for measuring
RCU grace-period performance and scalability, which is useful for
the expedited-grace-period changes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Jonathan writes:
2nd set of new device support, features and cleanup for IIO in the 4.7 cycle.
Bit of a bumper set for new drivers but plenty of other stuff here as well!
New device support
* ad5592R ADC/DAC
- new driver supporting ad5592r and ad5593r combined ADC/DAC and gpio chips.
* Aosong am2315 relative humidity
- new driver with triggered buffer support in follow up patch.
* bmi160 imu
- new driver
* bmp280
- bmp180 support - note there is support in the misc/bmp085 driver. Intent
is to remove that driver long term.
* invensense mpu6050
- cleanup leading to explicit support of mpu9150 with a good few cleanups
along the way.
* Hope RF hp03 pressure and temperature sensor.
- new driver
* maxim DS1803 potentiometer
- new driver
* maxim max44000 light and proximity sensor
- new driver built in a series of steps to support pretty much everything.
* ROHM BH1780 light sensor
- new driver. There is an existing driver in misc that this is pretty much
intended to replace. The discussion on whether to support the non standard
interface of that driver is some way is continuing.
* st-gyro
- lsm9ds0-gyro. The accel/magn side of this will take a while longer as
extensions to the st library are needed for cases where two types of sensor
share a single i2c address.
* ti-adc081c
- support the adc101c and adc121c
* Vishay VEML6070 UV sensor
- new driver.
New features
* core
- devm_ APIs for channel_get and channel_get_all. The first user of these
is the generic ADC based thermal driver. As it is going through the
thermal tree these will be picked up as a patch to that next cycle as that
is how the author preferred to do it.
- mounting matrix support. This new core support allows devices to provide
to userspace (typically from the device tree) allowing compensation for how
the sensor is mounted on the device. First examples are on UAVs but it
has a more mundane use on typical phone where the chip may be on the front
or the back of the circuit board and soldered at any angle. Includes
support for this ABI in ak8975 (which has an older interface, now
deprecated) and mpu6050.
* tools
- add a -a option to enable all available channels in generic_buffer sample.
Makes it somewhat easier to use.
* adis library and drivers
- support manual self test flag clearing. This has technically been broken
for a very long time - result is an offset on readings as the applied field
is on all the time.
* ak8975
- triggered buffer support
* bmc150
- spi support (including splitting the driver into core and i2c parts)
* bmp280
- oversampling support.
* dht11
- improved logging - useful to debug timing issues on this quirky device.
* st-sensors
- read each channel invidivually as not all support the optimization of
reading in bulk. This is technically a fix, but will need to be backported
if desired.
- support open drain and shared interrupts.
* ti-adc081c
- triggered buffer support.
Cleanups
* inkern
- white space fix.
* ad7606
- use the iio_device_claim_direct_mode call rather than open coding equiv.
* ad799x
- white space fix.
* ad9523
- unsigned -> unsigned int
* apds9660
- brace location tidying up.
- silence an uninitialized variable warning.
* ak8975
- else and brace on same line fix.
* at91_adc
- white space fixes.
* bmc150
- use regmap stored copy of the device pointer rather than having an
additional copy.
* bmg160
- use regmap stored copy of the device pointer rather than having an
additional copy.
* hid-sensors
- white space fixes.
* mcp3422
- white space fix.
* mma7455
- use regmap to retrieve the device struct rather than carrying another copy
in the private data.
* ms_sensors
- white space fix.
* mxs-lradc
- move current bindings out of staging - some will be shortly deprecated but
the reality is that we have device trees out there using them so they will
need to be supported for some time. They accidentally got left behind
when the driver graduated from staging.
- white space cleanup.
- set INPUT_PROP_DIRECT.
- move ts config into a better function.
- move the STMP reset out of the ADC init.
* vf610_adc
- case label indenting fix.
Perf is not able to register probe in kernel module when dwarf supprt
is not there(and so it goes for symtab). Perf passes full path of
module where only module name is required which is causing the problem.
This patch fixes this issue.
Before applying patch:
$ dpkg -s libdw-dev
dpkg-query: package 'libdw-dev' is not installed and no information is...
$ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
Added new event:
probe:kprobe_init (on kprobe_init in /linux/samples/kprobes/kprobe_example.ko)
You can now use it in all perf tools, such as:
perf record -e probe:kprobe_init -aR sleep 1
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/kprobe_init /linux/samples/kprobes/kprobe_example.ko:kprobe_init
$ sudo ./perf record -a -e probe:kprobe_init
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.105 MB perf.data ]
$ sudo ./perf script # No output here
After applying patch:
$ sudo ./perf probe -m /linux/samples/kprobes/kprobe_example.ko kprobe_init
Added new event:
probe:kprobe_init (on kprobe_init in kprobe_example)
You can now use it in all perf tools, such as:
perf record -e probe:kprobe_init -aR sleep 1
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/kprobe_init kprobe_example:kprobe_init
$ sudo ./perf record -a -e probe:kprobe_init
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.105 MB perf.data (2 samples) ]
$ sudo ./perf script
insmod 13990 [002] 5961.216833: probe:kprobe_init: ...
insmod 13995 [002] 5962.889384: probe:kprobe_init: ...
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Perf can add a probe on kernel module which has not been loaded yet.
The current implementation finds the module name from path. But if the
filename is different from the actual module name then perf fails to
register a probe while loading module because of mismatch in the names.
For example, samples/kobject/kobject-example.ko is loaded as
kobject_example.
Before applying patch:
$ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
Added new event:
probe:foo_show (on foo_show in kobject-example)
You can now use it in all perf tools, such as:
perf record -e probe:foo_show -aR sleep 1
$ cat /sys/kernel/debug/tracing/kprobe_events
p:probe/foo_show kobject-example:foo_show
$ insmod kobject-example.ko
$ lsmod
Module Size Used by
kobject_example 16384 0
Generate read to /sys/kernel/kobject_example/foo while recording data
with below command
$ sudo ./perf record -e probe:foo_show -a
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.093 MB perf.data ]
$./perf report --stdio -F overhead,comm,dso,sym
Error:
The perf.data.old file has no samples!
After applying patch:
$ sudo ./perf probe -m /linux/samples/kobject/kobject-example.ko foo_show
Added new event:
probe:foo_show (on foo_show in kobject_example)
You can now use it in all perf tools, such as:
perf record -e probe:foo_show -aR sleep 1
$ sudo cat /sys/kernel/debug/tracing/kprobe_events
p:probe/foo_show kobject_example:foo_show
$ insmod kobject-example.ko
$ lsmod
Module Size Used by
kobject_example 16384 0
Generate read to /sys/kernel/kobject_example/foo while recording data
with below command
$ sudo ./perf record -e probe:foo_show -a
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.097 MB perf.data (8 samples) ]
$ sudo ./perf report --stdio -F overhead,comm,dso,sym
...
# Samples: 8 of event 'probe:foo_show'
# Event count (approx.): 8
#
# Overhead Command Shared Object Symbol
# ........ ....... ................. ............
#
100.00% cat [kobject_example] [k] foo_show
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1461680741-12517-2-git-send-email-ravi.bangoria@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We get notifications for threads that gets created while we're tracing,
but for preexisting threads we may end not having synthesized them, like
when tracing a 'perf trace' session that will use '--pid' to trace some
other thread.
And besides we should probably stop synthesizing those records and
instead read thread information in a lazy way, i.e. just when we need,
like done in this patch:
Now the 'pid_t' argument in 'perf_event_open' gets translated to a COMM:
# perf trace -e perf_event_open perf stat -e cycles -p 31601
0.027 ( 0.027 ms): perf/23393 perf_event_open(attr_uptr: 0x2fdd0d8, pid: 31601 (abrt-dump-journ), cpu: -1, group_fd: -1, flags: FD_CLOEXEC)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= 3
^C
And in other syscalls containing pid_t without thread->comm_set at the
time of the formatting.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ioeps6dlwst17d6oozc9shtk@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Don't read broken data after 'head' pointer.
Following commits will feed perf_evlist__mmap_read() with some 'head'
pointers not maintained by kernel. If 'head' pointer breaks an event, we
should avoid reading from the broken event. This can happen in backward
ring buffer.
For example:
old head
| |
V V
+---+------+----------+----+-----+--+
|..E|D....D|C........C|B..B|A....|E.|
+---+------+----------+----+-----+--+
'old' pointer points to the beginning of 'A' and trying read from it,
but 'A' has been overwritten. In this case, don't try to read from 'A',
simply return NULL.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1461637738-62722-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Given that the 'val' parameter is ignored for FUTEX_LOCK_PI, get rid of
the bogus deadlock detection flag in the wrapper code and avoid the
extra argument, making it resemble its unlock counterpart. And if
nothing else, we already only pass 0 anyway.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dbueso@suse.de>
Link: http://lkml.kernel.org/r/1461208447-29328-1-git-send-email-dave@stgolabs.net
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This fixes a bug caused by an unitialized callchain cursor. The crash
frist appeared in:
6f736735e3 ("perf evsel: Require that callchains be resolved before
calling fprintf_{sym,callchain}")
The callchain cursor is a struct that contains pointers, that when
uninitialized will cause unpredictable behavior (usually a crash)
when trying to append to the callchain.
The existing implementation has the following issues:
1. The callchain cursor used is not initialized, resulting in
unpredictable behavior when used.
2. The cursor is declared on the stack. Even if it is properly initalized,
the implmentation will leak memory when the function returns,
since all the references to the callchain_nodes allocated by
callchain_cursor_append will be lost when the cursor goes out of
scope.
3. Storing the cursor on the stack is inefficient. Even if memory is
properly freed when it goes out of scope, a performance penalty
will be incurred due to reallocation of callchain nodes.
callchain_cursor_append is designed to avoid these reallocations
when an existing cursor is reused.
This patch fixes the crash by replacing cursor_callchain with a reference
to the global callchain_cursor which also resolves all 3 issues mentioned
above.
How to reproduce the crash:
$ perf record --call-graph=dwarf stress -t 1 -c 1
$ perf script > /dev/null
Segfault
Signed-off-by: Chris Phlipot <cphlipot0@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Fixes: 6f736735e3 ("perf evsel: Require that callchains be resolved before calling fprintf_{sym,callchain}")
Link: http://lkml.kernel.org/r/1461119531-2529-1-git-send-email-cphlipot0@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
write_buildid() increments 'name_len' with intention to take into
account trailing zero byte. However, 'name_len' was already incremented
in machine__write_buildid_table() before. So this leads to
out-of-bounds read in do_write():
$ ./perf record sleep 0
[ perf record: Woken up 1 times to write data ]
=================================================================
==15899==ERROR: AddressSanitizer: global-buffer-overflow on address 0x00000099fc92 at pc 0x7f1aa9c7eab5 bp 0x7fff940f84d0 sp 0x7fff940f7c78
READ of size 19 at 0x00000099fc92 thread T0
#0 0x7f1aa9c7eab4 (/usr/lib/gcc/x86_64-pc-linux-gnu/5.3.0/libasan.so.2+0x44ab4)
#1 0x649c5b in do_write util/header.c:67
#2 0x649c5b in write_padded util/header.c:82
#3 0x57e8bc in write_buildid util/build-id.c:239
#4 0x57e8bc in machine__write_buildid_table util/build-id.c:278
...
0x00000099fc92 is located 0 bytes to the right of global variable '*.LC99' defined in 'util/symbol.c' (0x99fc80) of size 18
'*.LC99' is ascii string '[kernel.kallsyms]'
...
Shadow bytes around the buggy address:
0x00008012bf80: f9 f9 f9 f9 00 00 00 00 00 00 03 f9 f9 f9 f9 f9
=>0x00008012bf90: 00 00[02]f9 f9 f9 f9 f9 00 00 00 00 00 05 f9 f9
0x00008012bfa0: f9 f9 f9 f9 00 03 f9 f9 f9 f9 f9 f9 00 00 00 00
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1461053847-5633-1-git-send-email-aryabinin@virtuozzo.com
[ Remove the off-by one at the origin, to keep len(s) == strlen(s) assumption ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf, cpu hotplug and timer fixes from Ingo Molnar:
"perf:
- A single tooling fix for a user-triggerable segfault.
CPU hotplug:
- Fix a CPU hotplug corner case regression, introduced by the recent
hotplug rework
timers:
- Fix a boot hang in the ARM based Tango SoC clocksource driver"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf intel-pt: Fix segfault tracing transactions
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Fix rollback during error-out in __cpu_disable()
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource/drivers/tango-xtal: Fix boot hang due to incorrect test
Pull objtool fixes from Ingo Molnar:
"A handful of objtool fixes: two improvements to how warnings are
printed plus a false positive warning fix, and build environment fix"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool: Fix Makefile to properly see if libelf is supported
objtool: Detect falling through to the next function
objtool: Add workaround for GCC switch jump table bug
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
Build fixes:
- Fix 'perf trace' build when DWARF unwind isn't available (Arnaldo Carvalho de Melo)
- Remove x86 references from arch-neutral Build, fixing it in !x86 arches,
reported as breaking the build for powerpc64le in linux-next (Arnaldo Carvalho de Melo)
Infrastructure changes:
- Do memset() variable 'st' using the correct size in the jit code (Colin Ian King)
- Fix postgresql ubuntu 'perf script' install instructions (Chris Phlipot)
- Use callchain_param more thoroughly when checking how callchains were
configured, eventually will be the only way to look for callchain parameters
(Arnaldo Carvalho de Melo)
- Fix some issues in the 'perf test kallsyms' entry (Arnaldo Carvalho de Melo)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation for providing an alternative (to block device) access
mechanism to persistent memory, convert pmem_rw_bytes() to
nsio_rw_bytes(). This allows ->rw_bytes() functionality without
requiring a 'struct pmem_device' to be instantiated.
In other words, when ->rw_bytes() is in use i/o is driven through
'struct nd_namespace_io', otherwise it is driven through 'struct
pmem_device' and the block layer. This consolidates the disjoint calls
to devm_exit_badblocks() and devm_memunmap() into a common
devm_nsio_disable() and cleans up the init path to use a unified
pmem_attach_disk() implementation.
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Currently, the rcutorture scripts do not test boot-time adjustment of
leaf fanout (via the rcutree.rcu_fanout_leaf boot parameter), as was noted
during testing carried out by Iftekhar Ahmed of Oregon State University.
This commit therefore adjusts TREE04's CONFIG_RCU_FANOUT_LEAF from 4 to 3,
and also adds rcutree.rcu_fanout_leaf=4 to its boot parameters. This
change forces RCU's boot-time geometry-change code to be exercised.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Currently, if the user specifies multiple runs of a given test
configuration, the scripting does multiple kernel builds. This wastes
both time and disk space, so this commit makes the scripting use the
first build for all runs of a given test configuration.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit adds a --jitter OS-jitter capability to expose bugs based
on no-delay assumptions.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Add sample_reg_mask array with pt_regs registers.
This is needed for printing supported regs ( -I? option).
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
