In ebebbf0823 ("perf top: Switch default mode to overwrite mode") we
forgot to leave a way to disable that new default, add a --overwrite
option that can be disabled using --no-overwrite, since the code already
in such a way that we can readily disable this mode.
This is useful when investigating bugs with this mode like the recent
report from David Miller where lots of unknown symbols appear due to
disabling the events while processing them which disables all record
types, not just PERF_RECORD_SAMPLE, which makes it impossible to resolve
maps when we lose PERF_RECORD_MMAP records.
This can be easily seen while building a kernel, when there are lots of
short lived processes.
Reported-by: David Miller <davem@davemloft.net>
Acked-by: Kan Liang <kan.liang@intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: ebebbf0823 ("perf top: Switch default mode to overwrite mode")
Link: https://lkml.kernel.org/n/tip-oqgsz2bq4kgrnnajrafcdhie@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The pathname beautifiers so far support just one augmented pathname per
syscall, so do it just for mount's first arg, later this will get fixed.
With:
# perf probe -l
probe:vfs_getname (on getname_flags:73@acme/git/linux/fs/namei.c with pathname)
#
Later this will get added to augmented_syscalls.c (eBPF):
In one xterm:
# perf trace -e mount,umount
2687.331 ( 3.544 ms): mount/8892 mount(dev_name: /mnt, dir_name: 0x561f9ac184a0, type: 0x561f9ac1b170, flags: BIND) = 0
3912.126 ( 8.807 ms): umount/8895 umount2(name: /mnt) = 0
^C#
In the other:
$ sudo mount --bind /proc /mnt
$ sudo umount /mnt
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Benjamin Peterson <benjamin@python.org>
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: https://lkml.kernel.org/n/tip-qsvhrm2es635cl4zicqjeth2@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
When trying to trace the 'umount' syscall on x86_64 I noticed that it
was failing:
# trace -e umount umount /mnt
event syntax error: 'umount'
\___ parser error
Run 'perf list' for a list of valid events
Usage: perf trace [<options>] [<command>]
or: perf trace [<options>] -- <command> [<options>]
or: perf trace record [<options>] [<command>]
or: perf trace record [<options>] -- <command> [<options>]
-e, --event <event> event/syscall selector. use 'perf list' to list available events
#
This is because in the x86-64 we have it just as 'umount2':
$ grep umount arch/x86/entry/syscalls/syscall_64.tbl
166 common umount2 __x64_sys_umount
$
So if the syscall name fails, try fallbacking to looking at the aliases
we have in the syscall_fmts table to then re-lookup, now:
# trace -e umount umount -f /mnt
umount: /mnt: not mounted.
1.759 ( 0.004 ms): umount/18365 umount2(name: 0x55fbfcbc4480, flags: 1) = -1 EINVAL Invalid argument
#
Time to beautify the flags arg :-)
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Benjamin Peterson <benjamin@python.org>
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: https://lkml.kernel.org/n/tip-ukweodgzbmjd25lfkgryeft1@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Take mount's 'flags' arg, to cope with this semantic, as defined in do_mount in fs/namespace.c:
/*
* Pre-0.97 versions of mount() didn't have a flags word. When the
* flags word was introduced its top half was required to have the
* magic value 0xC0ED, and this remained so until 2.4.0-test9.
* Therefore, if this magic number is present, it carries no
* information and must be discarded.
*/
We need to mask this arg, and then see if it is zero, when we simply
don't print the arg name and value.
The next patch will use this for mount's 'flag' arg.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Benjamin Peterson <benjamin@python.org>
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: https://lkml.kernel.org/n/tip-btue14k5jemayuykfrwsnh85@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull KVM updates from Radim Krčmář:
"ARM:
- Improved guest IPA space support (32 to 52 bits)
- RAS event delivery for 32bit
- PMU fixes
- Guest entry hardening
- Various cleanups
- Port of dirty_log_test selftest
PPC:
- Nested HV KVM support for radix guests on POWER9. The performance
is much better than with PR KVM. Migration and arbitrary level of
nesting is supported.
- Disable nested HV-KVM on early POWER9 chips that need a particular
hardware bug workaround
- One VM per core mode to prevent potential data leaks
- PCI pass-through optimization
- merge ppc-kvm topic branch and kvm-ppc-fixes to get a better base
s390:
- Initial version of AP crypto virtualization via vfio-mdev
- Improvement for vfio-ap
- Set the host program identifier
- Optimize page table locking
x86:
- Enable nested virtualization by default
- Implement Hyper-V IPI hypercalls
- Improve #PF and #DB handling
- Allow guests to use Enlightened VMCS
- Add migration selftests for VMCS and Enlightened VMCS
- Allow coalesced PIO accesses
- Add an option to perform nested VMCS host state consistency check
through hardware
- Automatic tuning of lapic_timer_advance_ns
- Many fixes, minor improvements, and cleanups"
* tag 'kvm-4.20-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (204 commits)
KVM/nVMX: Do not validate that posted_intr_desc_addr is page aligned
Revert "kvm: x86: optimize dr6 restore"
KVM: PPC: Optimize clearing TCEs for sparse tables
x86/kvm/nVMX: tweak shadow fields
selftests/kvm: add missing executables to .gitignore
KVM: arm64: Safety check PSTATE when entering guest and handle IL
KVM: PPC: Book3S HV: Don't use streamlined entry path on early POWER9 chips
arm/arm64: KVM: Enable 32 bits kvm vcpu events support
arm/arm64: KVM: Rename function kvm_arch_dev_ioctl_check_extension()
KVM: arm64: Fix caching of host MDCR_EL2 value
KVM: VMX: enable nested virtualization by default
KVM/x86: Use 32bit xor to clear registers in svm.c
kvm: x86: Introduce KVM_CAP_EXCEPTION_PAYLOAD
kvm: vmx: Defer setting of DR6 until #DB delivery
kvm: x86: Defer setting of CR2 until #PF delivery
kvm: x86: Add payload operands to kvm_multiple_exception
kvm: x86: Add exception payload fields to kvm_vcpu_events
kvm: x86: Add has_payload and payload to kvm_queued_exception
KVM: Documentation: Fix omission in struct kvm_vcpu_events
KVM: selftests: add Enlightened VMCS test
...
By default 'perf script' for itrace outputs sampled instructions or
branches. In my experience this is confusing to users because it's hard
to correlate with real program behavior. The sampling makes sense for
tools like 'perf report' that actually sample to reduce the run time,
but run time is normally not a problem for 'perf script'. It's better
to give an accurate representation of the program flow.
Default 'perf script' to output all calls for itrace. That's a much saner
default. The old behavior can be still requested with 'perf script'
--itrace=ibxwpe100000
v2: Fix ETM build failure
v3: Really fix ETM build failure (Kim Phillips)
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Kim Phillips <kim.phillips@arm.com>
Cc: Leo Yan <leo.yan@linaro.org>
Link: http://lkml.kernel.org/r/20180920180540.14039-3-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull networking updates from David Miller:
1) Add VF IPSEC offload support in ixgbe, from Shannon Nelson.
2) Add zero-copy AF_XDP support to i40e, from Björn Töpel.
3) All in-tree drivers are converted to {g,s}et_link_ksettings() so we
can get rid of the {g,s}et_settings ethtool callbacks, from Michal
Kubecek.
4) Add software timestamping to veth driver, from Michael Walle.
5) More work to make packet classifiers and actions lockless, from Vlad
Buslov.
6) Support sticky FDB entries in bridge, from Nikolay Aleksandrov.
7) Add ipv6 version of IP_MULTICAST_ALL sockopt, from Andre Naujoks.
8) Support batching of XDP buffers in vhost_net, from Jason Wang.
9) Add flow dissector BPF hook, from Petar Penkov.
10) i40e vf --> generic iavf conversion, from Jesse Brandeburg.
11) Add NLA_REJECT netlink attribute policy type, to signal when users
provide attributes in situations which don't make sense. From
Johannes Berg.
12) Switch TCP and fair-queue scheduler over to earliest departure time
model. From Eric Dumazet.
13) Improve guest receive performance by doing rx busy polling in tx
path of vhost networking driver, from Tonghao Zhang.
14) Add per-cgroup local storage to bpf
15) Add reference tracking to BPF, from Joe Stringer. The verifier can
now make sure that references taken to objects are properly released
by the program.
16) Support in-place encryption in TLS, from Vakul Garg.
17) Add new taprio packet scheduler, from Vinicius Costa Gomes.
18) Lots of selftests additions, too numerous to mention one by one here
but all of which are very much appreciated.
19) Support offloading of eBPF programs containing BPF to BPF calls in
nfp driver, frm Quentin Monnet.
20) Move dpaa2_ptp driver out of staging, from Yangbo Lu.
21) Lots of u32 classifier cleanups and simplifications, from Al Viro.
22) Add new strict versions of netlink message parsers, and enable them
for some situations. From David Ahern.
23) Evict neighbour entries on carrier down, also from David Ahern.
24) Support BPF sk_msg verdict programs with kTLS, from Daniel Borkmann
and John Fastabend.
25) Add support for filtering route dumps, from David Ahern.
26) New igc Intel driver for 2.5G parts, from Sasha Neftin et al.
27) Allow vxlan enslavement to bridges in mlxsw driver, from Ido
Schimmel.
28) Add queue and stack map types to eBPF, from Mauricio Vasquez B.
29) Add back byte-queue-limit support to r8169, with all the bug fixes
in other areas of the driver it works now! From Florian Westphal and
Heiner Kallweit.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2147 commits)
tcp: add tcp_reset_xmit_timer() helper
qed: Fix static checker warning
Revert "be2net: remove desc field from be_eq_obj"
Revert "net: simplify sock_poll_wait"
net: socionext: Reset tx queue in ndo_stop
net: socionext: Add dummy PHY register read in phy_write()
net: socionext: Stop PHY before resetting netsec
net: stmmac: Set OWN bit for jumbo frames
arm64: dts: stratix10: Support Ethernet Jumbo frame
tls: Add maintainers
net: ethernet: ti: cpsw: unsync mcast entries while switch promisc mode
octeontx2-af: Support for NIXLF's UCAST/PROMISC/ALLMULTI modes
octeontx2-af: Support for setting MAC address
octeontx2-af: Support for changing RSS algorithm
octeontx2-af: NIX Rx flowkey configuration for RSS
octeontx2-af: Install ucast and bcast pkt forwarding rules
octeontx2-af: Add LMAC channel info to NIXLF_ALLOC response
octeontx2-af: NPC MCAM and LDATA extract minimal configuration
octeontx2-af: Enable packet length and csum validation
octeontx2-af: Support for VTAG strip and capture
...
Displaying all the database tables can help make the database easier to
understand.
Committer testing:
Opened all the tables, even the sqlite master table, which I selected
everything and used control+C, lets see if it works...
CREATE VIEW threads_view AS SELECT id,machine_id,(SELECT host_or_guest FROM machines_view WHERE id = machine_id) AS host_or_guest,process_id,pid,tid FROM threads
Humm, nope, just one of the cells got copied, even with everything selected :-)
Anyway, works as advertised, useful for perusing the data.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-17-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add a Find bar that appears at the bottom of the call-graph window.
Committer testing:
Using:
python tools/perf/scripts/python/exported-sql-viewer.py pt_example branches calls
Using the database built in the first "Committer Testing" section in
this patch series I was able to:
"Reports"
"Context-Sensitive Call Graphs"
Control+F or select "Edit" in the top menu then "Find"
__poll<ENTER>
and find the first place where the "__poll" function appears, then
press the down arrow in the lower right corner and go to the next, etc.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-15-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Use Qt MDI (multiple document interface) to support multiple sub-windows.
Put the data model in a cache so that each sub-window can share the same
data. This allows mutiple views of the call-graph at the same time and
paves the way to add more reports.
Committer testing:
Starts with a "File Reports Windows" main menu, from the "Reports" I
can get what was available up to now, the "Context-Sensitivi Call Graph"
option.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-14-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
class TreeItem represents items at all levels of the call-graph tree.
However, not all the levels represent the same data i.e. the top-level is
comms, the next level is threads, and subsequent levels are functions.
Consequently it is simpler to have separate classes for different levels
with commonality in a base class. Refactor TreeItem class accordingly.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-12-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Set initial column sizes to improve initial display.
Committer testing:
Extended instructions on testing this, using the sqlite variant:
Make sure you have the SQLite glue for python+Qt installed, on fedora 27
I used:
# dnf install python-pyside
Collect some PT samples, say 5-secs worth, system wide:
# perf record -r 10 -e intel_pt//u -a sleep 5
[ perf record: Woken up 49 times to write data ]
[ perf record: Captured and wrote 96.131 MB perf.data ]
This results in this perf.data file:
# ls -larth perf.data
-rw-------. 1 root root 97M Oct 23 10:11 perf.data
With the following attributes:
# perf evlist -v
intel_pt//u: type: 8, size: 112, config: 0x300e601, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, exclude_kernel: 1, exclude_hv: 1, sample_id_all: 1
dummy:u: type: 1, size: 112, config: 0x9, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CPU|IDENTIFIER, read_format: ID, inherit: 1, exclude_kernel: 1, exclude_hv: 1, mmap: 1, comm: 1, task: 1, sample_id_all: 1, mmap2: 1, comm_exec: 1, context_switch: 1
#
Then generate the "pt_example" tables using:
# perf script -s ~/libexec/perf-core/scripts/python/export-to-sqlite.py pt_example branches calls
2018-10-23 10:56:59.177711 Creating database...
2018-10-23 10:56:59.195842 Writing records...
instruction trace error type 1 cpu 2 pid 1644 tid 1644 ip 0x263984516750 code 5: Failed to get instruction
instruction trace error type 1 cpu 2 pid 1644 tid 1644 ip 0x7f26e116fd20 code 6: Trace doesn't match instruction
instruction trace error type 1 cpu 2 pid 1644 tid 1644 ip 0x7f26e162c9ee code 6: Trace doesn't match instruction
instruction trace error type 1 cpu 2 pid 1644 tid 1644 ip 0x7f26e9ce831a code 6: Trace doesn't match instruction
<SNIP>
instruction trace error type 1 cpu 0 pid 1644 tid 1644 ip 0x7f26e13d07b4 code 6: Trace doesn't match instruction
Warning:
132 instruction trace errors
2018-10-23 11:25:25.015717 Adding indexes
2018-10-23 11:25:28.788061 Done
#
In my example, that perf.data file generated this db:
# file pt_example
pt_example: SQLite 3.x database, last written using SQLite version 3020001
[root@seventh perf]# ls -lah pt_example
-rw-r--r--. 1 root root 6.6G Oct 23 11:25 pt_example
#
Then use this python script to use that db and provide a GUI:
$ python tools/perf/scripts/python/call-graph-from-sql.py pt_example branches calls
I compared the column widths before this patch and after applying it,
the visual results match the patch intent.
The following patches will refer to this set of instructions in the "Committer
Testing" section.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181001062853.28285-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf updates from Ingo Molnar:
"The main updates in this cycle were:
- Lots of perf tooling changes too voluminous to list (big perf trace
and perf stat improvements, lots of libtraceevent reorganization,
etc.), so I'll list the authors and refer to the changelog for
details:
Benjamin Peterson, Jérémie Galarneau, Kim Phillips, Peter
Zijlstra, Ravi Bangoria, Sangwon Hong, Sean V Kelley, Steven
Rostedt, Thomas Gleixner, Ding Xiang, Eduardo Habkost, Thomas
Richter, Andi Kleen, Sanskriti Sharma, Adrian Hunter, Tzvetomir
Stoyanov, Arnaldo Carvalho de Melo, Jiri Olsa.
... with the bulk of the changes written by Jiri Olsa, Tzvetomir
Stoyanov and Arnaldo Carvalho de Melo.
- Continued intel_rdt work with a focus on playing well with perf
events. This also imported some non-perf RDT work due to
dependencies. (Reinette Chatre)
- Implement counter freezing for Arch Perfmon v4 (Skylake and newer).
This allows to speed up the PMI handler by avoiding unnecessary MSR
writes and make it more accurate. (Andi Kleen)
- kprobes cleanups and simplification (Masami Hiramatsu)
- Intel Goldmont PMU updates (Kan Liang)
- ... plus misc other fixes and updates"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (155 commits)
kprobes/x86: Use preempt_enable() in optimized_callback()
x86/intel_rdt: Prevent pseudo-locking from using stale pointers
kprobes, x86/ptrace.h: Make regs_get_kernel_stack_nth() not fault on bad stack
perf/x86/intel: Export mem events only if there's PEBS support
x86/cpu: Drop pointless static qualifier in punit_dev_state_show()
x86/intel_rdt: Fix initial allocation to consider CDP
x86/intel_rdt: CBM overlap should also check for overlap with CDP peer
x86/intel_rdt: Introduce utility to obtain CDP peer
tools lib traceevent, perf tools: Move struct tep_handler definition in a local header file
tools lib traceevent: Separate out tep_strerror() for strerror_r() issues
perf python: More portable way to make CFLAGS work with clang
perf python: Make clang_has_option() work on Python 3
perf tools: Free temporary 'sys' string in read_event_files()
perf tools: Avoid double free in read_event_file()
perf tools: Free 'printk' string in parse_ftrace_printk()
perf tools: Cleanup trace-event-info 'tdata' leak
perf strbuf: Match va_{add,copy} with va_end
perf test: S390 does not support watchpoints in test 22
perf auxtrace: Include missing asm/bitsperlong.h to get BITS_PER_LONG
tools include: Adopt linux/bits.h
...
When the perf script output is written to a terminal stream, the normal
output of `perf script` would get buffered, but its debug output would
be written directly. This made it quite hard to figure out where a given
debug output is coming from.
We can improve on this by flushing the output buffer after processing an
event. To see the value, compare the following output for a `perf script
-v` run:
Before this patch:
```
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
unwind: find_proc_info dso /usr/lib/ld-2.28.so
unwind: reg 6, val 0
unwind: _start:ip = 0x7faf7dfdc000 (0x2000)
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
unwind: find_proc_info dso /usr/lib/ld-2.28.so
unwind: reg 6, val 0
unwind: _start:ip = 0x7faf7dfdc000 (0x2000)
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
unwind: find_proc_info dso /usr/lib/ld-2.28.so
unwind: reg 6, val 0
unwind: _start:ip = 0x7faf7dfdc000 (0x2000)
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
... lots and lots of verbose debug output
cpp-inlining 24617 90229.122036534: 1 cycles:uppp:
7faf7dfdc000 _start+0x0 (/usr/lib/ld-2.28.so)
cpp-inlining 24617 90229.122043974: 1 cycles:uppp:
7faf7dfdc000 _start+0x0 (/usr/lib/ld-2.28.so)
...
```
After this patch:
```
...
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
unwind: find_proc_info dso /usr/lib/ld-2.28.so
unwind: reg 6, val 0
unwind: _start:ip = 0x7faf7dfdc000 (0x2000)
cpp-inlining 24617 90229.122036534: 1 cycles:uppp:
7faf7dfdc000 _start+0x0 (/usr/lib/ld-2.28.so)
unwind: reg 16, val 7faf7dfdc000
unwind: reg 7, val 7ffc80811e30
unwind: find_proc_info dso /usr/lib/ld-2.28.so
unwind: reg 6, val 0
unwind: _start:ip = 0x7faf7dfdc000 (0x2000)
cpp-inlining 24617 90229.122043974: 1 cycles:uppp:
7faf7dfdc000 _start+0x0 (/usr/lib/ld-2.28.so)
...
```
This new output format makes it much easier to use perf script output
for debugging purposes, e.g. to investigate broken dwarf unwinding.
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/20181021191424.16183-2-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The script tool isn't using a browser, yet use_browser wasn't set
explicitly to zero. This in turn lead to confusing output such as:
```
$ perf script -vvv ...
...
overlapping maps in /home/milian/foobar (disable tui for more info)
...
```
Explicitly set use_browser to 0 now, which gives us the extended
debug information now in perf script as expected.
Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: http://lkml.kernel.org/r/20181021191424.16183-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Daniel Borkmann says:
====================
pull-request: bpf-next 2018-10-21
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Implement two new kind of BPF maps, that is, queue and stack
map along with new peek, push and pop operations, from Mauricio.
2) Add support for MSG_PEEK flag when redirecting into an ingress
psock sk_msg queue, and add a new helper bpf_msg_push_data() for
insert data into the message, from John.
3) Allow for BPF programs of type BPF_PROG_TYPE_CGROUP_SKB to use
direct packet access for __skb_buff, from Song.
4) Use more lightweight barriers for walking perf ring buffer for
libbpf and perf tool as well. Also, various fixes and improvements
from verifier side, from Daniel.
5) Add per-symbol visibility for DSO in libbpf and hide by default
global symbols such as netlink related functions, from Andrey.
6) Two improvements to nfp's BPF offload to check vNIC capabilities
in case prog is shared with multiple vNICs and to protect against
mis-initializing atomic counters, from Jakub.
7) Fix for bpftool to use 4 context mode for the nfp disassembler,
also from Jakub.
8) Fix a return value comparison in test_libbpf.sh and add several
bpftool improvements in bash completion, documentation of bpf fs
restrictions and batch mode summary print, from Quentin.
9) Fix a file resource leak in BPF selftest's load_kallsyms()
helper, from Peng.
10) Fix an unused variable warning in map_lookup_and_delete_elem(),
from Alexei.
11) Fix bpf_skb_adjust_room() signature in BPF UAPI helper doc,
from Nicolas.
12) Add missing executables to .gitignore in BPF selftests, from Anders.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, on x86-64, perf uses LFENCE and MFENCE (rmb() and mb(),
respectively) when processing events from the perf ring buffer which
is unnecessarily expensive as we can do more lightweight in particular
given this is critical fast-path in perf.
According to Peter rmb()/mb() were added back then via a94d342b9c
("tools/perf: Add required memory barriers") at a time where kernel
still supported chips that needed it, but nowadays support for these
has been ditched completely, therefore we can fix them up as well.
While for x86-64, replacing rmb() and mb() with smp_*() variants would
result in just a compiler barrier for the former and LOCK + ADD for
the latter (__sync_synchronize() uses slower MFENCE by the way), Peter
suggested we can use smp_{load_acquire,store_release}() instead for
architectures where its implementation doesn't resolve in slower smp_mb().
Thus, e.g. in x86-64 we would be able to avoid CPU barrier entirely due
to TSO. For architectures where the latter needs to use smp_mb() e.g.
on arm, we stick to cheaper smp_rmb() variant for fetching the head.
This work adds helpers ring_buffer_read_head() and ring_buffer_write_tail()
for tools infrastructure that either switches to smp_load_acquire() for
architectures where it is cheaper or uses READ_ONCE() + smp_rmb() barrier
for those where it's not in order to fetch the data_head from the perf
control page, and it uses smp_store_release() to write the data_tail.
Latter is smp_mb() + WRITE_ONCE() combination or a cheaper variant if
architecture allows for it. Those that rely on smp_rmb() and smp_mb() can
further improve performance in a follow up step by implementing the two
under tools/arch/*/include/asm/barrier.h such that they don't have to
fallback to rmb() and mb() in tools/include/asm/barrier.h.
Switch perf to use ring_buffer_read_head() and ring_buffer_write_tail()
so it can make use of the optimizations. Later, we convert libbpf as
well to use the same helpers.
Side note [0]: the topic has been raised of whether one could simply use
the C11 gcc builtins [1] for the smp_load_acquire() and smp_store_release()
instead:
__atomic_load_n(ptr, __ATOMIC_ACQUIRE);
__atomic_store_n(ptr, val, __ATOMIC_RELEASE);
Kernel and (presumably) tooling shipped along with the kernel has a
minimum requirement of being able to build with gcc-4.6 and the latter
does not have C11 builtins. While generally the C11 memory models don't
align with the kernel's, the C11 load-acquire and store-release alone
/could/ suffice, however. Issue is that this is implementation dependent
on how the load-acquire and store-release is done by the compiler and
the mapping of supported compilers must align to be compatible with the
kernel's implementation, and thus needs to be verified/tracked on a
case by case basis whether they match (unless an architecture uses them
also from kernel side). The implementations for smp_load_acquire() and
smp_store_release() in this patch have been adapted from the kernel side
ones to have a concrete and compatible mapping in place.
[0] http://patchwork.ozlabs.org/patch/985422/
[1] https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This simply adds the field to 'struct perf_evsel' and allows setting
it via the event parser, to test it lets trace trace:
First look at where in a function that receives an evsel we can put a probe
to read how evsel->max_events was setup:
# perf probe -x ~/bin/perf -L trace__event_handler
<trace__event_handler@/home/acme/git/perf/tools/perf/builtin-trace.c:0>
0 static int trace__event_handler(struct trace *trace, struct perf_evsel *evsel,
union perf_event *event __maybe_unused,
struct perf_sample *sample)
3 {
4 struct thread *thread = machine__findnew_thread(trace->host, sample->pid, sample->tid);
5 int callchain_ret = 0;
7 if (sample->callchain) {
8 callchain_ret = trace__resolve_callchain(trace, evsel, sample, &callchain_cursor);
9 if (callchain_ret == 0) {
10 if (callchain_cursor.nr < trace->min_stack)
11 goto out;
12 callchain_ret = 1;
}
}
See what variables we can probe at line 7:
# perf probe -x ~/bin/perf -V trace__event_handler:7
Available variables at trace__event_handler:7
@<trace__event_handler+89>
int callchain_ret
struct perf_evsel* evsel
struct perf_sample* sample
struct thread* thread
struct trace* trace
union perf_event* event
Add a probe at that line asking for evsel->max_events to be collected and named
as "max_events":
# perf probe -x ~/bin/perf trace__event_handler:7 'max_events=evsel->max_events'
Added new event:
probe_perf:trace__event_handler (on trace__event_handler:7 in /home/acme/bin/perf with max_events=evsel->max_events)
You can now use it in all perf tools, such as:
perf record -e probe_perf:trace__event_handler -aR sleep 1
Now use 'perf trace', here aliased to just 'trace' and trace trace, i.e.
the first 'trace' is tracing just that 'probe_perf:trace__event_handler' event,
while the traced trace is tracing all scheduler tracepoints, will stop at two
events (--max-events 2) and will just set evsel->max_events for all the sched
tracepoints to 9, we will see the output of both traces intermixed:
# trace -e *perf:*event_handler trace --max-events 2 -e sched:*/nr=9/
0.000 :0/0 sched:sched_waking:comm=rcu_sched pid=10 prio=120 target_cpu=000
0.009 :0/0 sched:sched_wakeup:comm=rcu_sched pid=10 prio=120 target_cpu=000
0.000 trace/23949 probe_perf:trace__event_handler:(48c34a) max_events=0x9
0.046 trace/23949 probe_perf:trace__event_handler:(48c34a) max_events=0x9
#
Now, if the traced trace sends its output to /dev/null, we'll see just
what the first level trace outputs: that evsel->max_events is indeed
being set to 9:
# trace -e *perf:*event_handler trace -o /dev/null --max-events 2 -e sched:*/nr=9/
0.000 trace/23961 probe_perf:trace__event_handler:(48c34a) max_events=0x9
0.030 trace/23961 probe_perf:trace__event_handler:(48c34a) max_events=0x9
#
Now that we can set evsel->max_events, we can go to the next step, honour that
per-event property in 'perf trace'.
Cc: Adrian Hunter <adrian.hunter@intel.com>
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: https://lkml.kernel.org/n/tip-og00yasj276joem6e14l1eas@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
KVM/arm updates for 4.20
- Improved guest IPA space support (32 to 52 bits)
- RAS event delivery for 32bit
- PMU fixes
- Guest entry hardening
- Various cleanups
