We want to know when the fd went away, like when a monitored thread
exits.
If we do not monitor such events, then the tools will wait forever on
events from a vanished thread, like when running:
$ sleep 5s &
$ perf record -p `pidof sleep`
This builds upon the kernel patch by Jiri Olsa that actually makes a
poll on those file descriptors to return POLLHUP.
It is also needed to change the tools to use
perf_evlist__filter_pollfd() to check if there are remainings fds to
monitor or if all are gone, in which case they will exit the
poll/mmap/read loop.
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-a4fslwspov0bs69nj825hqpq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch restructures the memory controller (IMC) uncore PMU support
for client SNB/IVB/HSW processors. The main change is that it can now
cope with more than one PCI device ID per processor model. There are
many flavors of memory controllers for each processor. They have
different PCI device ID, yet they behave the same w.r.t. the memory
controller PMU that we are interested in.
The patch now supports two distinct memory controllers for IVB
processors: one for mobile, one for desktop.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140917090616.GA11281@quad
Cc: ak@linux.intel.com
Cc: kan.liang@intel.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The IvyBridge-EP uncore driver was missing three filter flags:
NC, ISOC, C6 which are useful in some cases. Support them in the same way
as the Haswell EP driver, by allowing to set them and exposing
them in the sysfs formats.
Also fix a typo in a define.
Relies on the Haswell EP driver to be applied earlier.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1409872109-31645-4-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use the newly added Broadwell cache event list for Haswell too.
All Haswell and Broadwell events and offcore masks used in these lists
are identical.
However Haswell is very different from the Sandy Bridge
list that was used previously. That fixes a wide range of mis-counting
cache events.
The node events are now only for retired memory events, so prefetching
and speculative memory accesses are not included. They are PEBS
capable now, which makes it much easier to sample for them, plus it's
possible to create address maps with -d.
The prefetch events are gone now. They way the hardware counts
them is very misleading (some prefetches included, others not), so
it seemed best to leave them out.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409683455-29168-5-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
On Broadwell INST_RETIRED.ALL cannot be used with any period
that doesn't have the lowest 6 bits cleared. And the period
should not be smaller than 128.
Add a new callback to enforce this, and set it for Broadwell.
This is erratum BDM57 and BDM11.
How does this handle the case when an app requests a specific
period with some of the bottom bits set
The apps thinks it is sampling at X occurences per sample, when it is
in fact at X - 63 (worst case).
Short answer:
Any useful instruction sampling period needs to be 4-6 orders
of magnitude larger than 128, as an PMI every 128 instructions
would instantly overwhelm the system and be throttled.
So the +-64 error from this is really small compared to the
period, much smaller than normal system jitter.
Long answer:
<write up by Peter:>
IFF we guarantee perf_event_attr::sample_period >= 128.
Suppose we start out with sample_period=192; then we'll set period_left
to 192, we'll end up with left = 128 (we truncate the lower bits). We
get an interrupt, find that period_left = 64 (>0 so we return 0 and
don't get an overflow handler), up that to 128. Then we trigger again,
at n=256. Then we find period_left = -64 (<=0 so we return 1 and do get
an overflow). We increment with sample_period so we get left = 128. We
fire again, at n=384, period_left = 0 (<=0 so we return 1 and get an
overflow). And on and on.
So while the individual interrupts are 'wrong' we get then with
interval=256,128 in exactly the right ratio to average out at 192. And
this works for everything >=128.
So the num_samples*fixed_period thing is still entirely correct +- 127,
which is good enough I'd say, as you already have that error anyhow.
So no need to 'fix' the tools, al we need to do is refuse to create
INST_RETIRED:ALL events with sample_period < 128.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Maria Dimakopoulou <maria.n.dimakopoulou@gmail.com>
Cc: Mark Davies <junk@eslaf.co.uk>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1409683455-29168-4-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add Broadwell support for Broadwell Client to perf. This is very
similar to Haswell. It uses a new cache event table, because there
were various changes there.
The constraint list has one new event that needs to be handled over
Haswell.
The PEBS event list is the same, so we reuse Haswell's.
[fengguang.wu: make intel_bdw_event_constraints[] static]
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: eranian@google.com
Link: http://lkml.kernel.org/r/1409683455-29168-3-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:
User visible changes:
o Add +field argument support for --sort option (Jiri Olsa)
o Do not access kallsyms when analyzing user binaries with 'probe' (Masami Hiramatsu)
o Ignore stripped vmlinux and fallback to kallsyms (Anton Blanchard)
o Add path to Ubuntu kernel debuginfo file (Anton Blanchard)
o Disable kernel symbol demangling by default (Avi Kivity)
Infrastructure changes:
o More intel PT prep work, from Adrian Hunter, including:
- Let a user specify a PMU event without any config terms
- Add perf-with-kcore script
- Let default config be defined for a PMU
- Add perf_pmu__scan_file()
o "perf kvm stat report" improvements by Alexander Yarygin:
o Save pid string in opts.target.pid
o Enable the target.system_wide flag
o Unify the title bar output
o Fix build issue on powerpc when DWARF support is disabled (Anton Blanchard)
o Allow to specify lib compile variable for spec usage (Jiri Olsa)
o Fix build on ARM (Stephane Eranian)
o Fix build on powerpc when DWARF support is disabled (Anton Blanchard)
o Don't include sys/poll.h directly (Arnaldo Carvalho de Melo)
o Use ring buffer consume method to look like other tools (Arnaldo Carvalho de Melo)
o Allow to specify lib compile variable for spec usage (Jiri Olsa)
o Fix GNU-only grep usage in Makefile (John Spencer)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Do not access kallsyms to show available variables and show source lines
in user binaries.
This behavior always requires the root privilege when sysctl sets
kernel.kptr_restrict=1, but we don't need it just for analyzing user
binaries.
Without this patch (by normal user, kptr_restrict=1):
----
$ perf probe -x ./perf -V add_cmdname
Failed to init vmlinux path.
Error: Failed to show vars.
$ perf probe -x ./perf -L add_cmdname
Failed to init vmlinux path.
Error: Failed to show lines.
----
With this patch:
----
$ perf probe -x ./perf -V add_cmdname
Available variables at add_cmdname
@<perf_unknown_cmd_config+144>
(No matched variables)
@<list_commands_in_dir+160>
(No matched variables)
@<add_cmdname+0>
char* name
size_t len
struct cmdnames* cmds
$ perf probe -x ./perf -L add_cmdname
<add_cmdname@/home/fedora/ksrc/linux-3/tools/perf/util/help.c:0>
0 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len)
1 {
2 struct cmdname *ent = malloc(sizeof(*ent) + len + 1);
4 ent->len = len;
5 memcpy(ent->name, name, len);
6 ent->name[len] = 0;
...
----
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: david lerner <dlernerdroid@gmail.com>
Cc: linux-perf-user@vger.kernel.org
Cc: yrl.pp-manager.tt@hitachi.com
Link: http://lkml.kernel.org/r/20140917084054.3722.73975.stgit@kbuild-f20.novalocal
[ Added missing 'bool user' argument to the !DWARF show_line_range() stub ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
If a vmlinux is stripped, perf will use it and ignore kallsyms. We
end up with useless profiles where everything maps to a few
runtime symbols:
63.39% swapper [kernel.kallsyms] [k] hcall_real_table
4.90% beam.smp [kernel.kallsyms] [k] hcall_real_table
4.44% beam.smp [kernel.kallsyms] [k] __sched_text_start
3.72% beam.smp [kernel.kallsyms] [k] __run_at_kexec
Detect this case and fallback to using kallsyms. This fixes the issue:
62.81% swapper [kernel.kallsyms] [k] snooze_loop
4.44% beam.smp [kernel.kallsyms] [k] __schedule
0.91% beam.smp [kernel.kallsyms] [k] _switch
0.73% beam.smp [kernel.kallsyms] [k] put_prev_entity
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
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/20140909085929.4a5a81f0@kryten
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Decoding an Intel PT trace of the kernel requires an accurate kernel
object image. This is provided by making a copy of kcore. However the
copy needs to be made under the same conditions as the original
recording, and then it needs to be associated with the perf.data file.
The perf-with-kcore script does that.
The script also checks the permissions on the buildid cache and can be
used to fix them. That is needed for distributions where root does not
have a home directory and consequently writes to the same buildid cache
as the user, resulting in cached files that the user does not have
access to.
Example:
$ ./perf-with-kcore
Usage: perf-with-kcore <perf sub-command> <perf.data directory> [<sub-command options> [ -- <workload>]]
<perf sub-command> can be record, script, report or inject
or: perf-with-kcore fix_buildid_cache_permissions
$ ./perf-with-kcore record pt_uname -e intel_pt// -- uname
Recording
Using /home/ahunter/bin/perf
perf version 3.15.rc3.g4549ba
/home/ahunter/bin/perf record -o pt_uname/perf.data -e intel_pt// -- uname
Linux
[ perf record: Woken up 3 times to write data ]
[ perf record: Captured and wrote 0.023 MB pt_uname/perf.data ]
Copying kcore
[sudo] password for ahunter:
Done
$ tools/perf/perf-with-kcore.sh script pt_uname | head
Using /home/ahunter/bin/perf
perf version 3.15.rc3.g4549ba
/home/ahunter/bin/perf script -i pt_uname/perf.data --kallsyms=pt_uname/kcore_dir/kallsyms
swapper 0 [002] 161533.969666: sched:sched_switch: swapper/2:0 [120] R ==> perf:11316 [120]
:11315 11315 [003] 161533.969704: sched:sched_switch: perf:11315 [120] S ==> swapper/3:0 [120]
:11316 11316 [002] 161533.969783: sched:sched_switch: perf:11316 [120] R ==> migration/2:33 [0]
:33 33 [002] 161533.969791: sched:sched_switch: migration/2:33 [0] S ==> swapper/2:0 [120]
swapper 0 [003] 161533.969792: sched:sched_switch: swapper/3:0 [120] R ==> perf:11316 [120]
:11316 11316 [003] 161533.970062: branches: 0 [unknown] ([unknown]) => ffffffff810532fa native_write_msr_safe ([kernel.kallsyms])
:11316 11316 [003] 161533.970062: branches: ffffffff810532fd native_write_msr_safe ([kernel.kallsyms]) => ffffffff81035b31 pt_config_start ([kernel.kallsyms])
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1406786474-9306-30-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This enables a PMU event to be specified in the form:
pmu//
which is effectively the same as:
pmu/config=0/
This patch is a precursor to defining default config for a PMU.
Further explanation extracted from lkml thread:
Imagine that the 'tsc' term did not exist.
Intel PT trace data would not contain TSC packets, and the decoder would
not know how to decode them.
Then imagine that a new version of the hardware adds 'tsc'.
It is such a useful feature that we want it by default, but older
versions of the tools don't know how to decode it, so the kernel cannot
turn it on by default.
It is similar to why the kernel does not select perf_event_attr.mmap2 by
default.
The kernel doesn't know whether the tool supports it.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1408129739-17368-6-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The new split Intel uncore driver code that recently went
into tip added a section mismatch, which the build process
complains about.
uncore_pmu_register() can be called from uncore_pci_probe,()
which is not __init and can be called from pci driver ->probe.
I'm not fully sure if it's actually possible to call the probe
function later, but it seems safer to mark uncore_pmu_register
not __init.
This also fixes the warning.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1409332858-29039-1-git-send-email-andi@firstfloor.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/20140822132605.GA20130@ada
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The use of "rcu_assign_pointer()" is NULLing out the pointer.
According to RCU_INIT_POINTER()'s block comment:
"1. This use of RCU_INIT_POINTER() is NULLing out the pointer"
it is better to use it instead of rcu_assign_pointer() because it has a
smaller overhead.
The following Coccinelle semantic patch was used:
@@
@@
- rcu_assign_pointer
+ RCU_INIT_POINTER
(..., NULL)
Signed-off-by: Andreea-Cristina Bernat <bernat.ada@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: paulmck@linux.vnet.ibm.com
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Link: http://lkml.kernel.org/r/20140822141536.GA32051@ada
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The NFS/RDMA Kconfig symbol was split into separate options for client
and server in commit 2e8c12e1b7 ("xprtrdma: add separate Kconfig
options for NFSoRDMA client and server support").
Update the documentation to reflect this split.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "J. Bruce Fields" <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The example code provided with the i2c device interface documentation
won't compile since it uses the reserved word "register" to name a
variable.
The compiler fails with this error message:
error: expected identifier or '(' before '=' token
__u8 register = 0x20; /* Device register to access */
^
Rename the variable "register" to simply "reg" in the example code.
Another couple of typos has been fixed as well.
[Change "! =" to "!=".]
Signed-off-by: Jose Alarcon Roldan <jose.alarcon.roldan@gmail.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
