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Since 'perf top' shares the histogram browser with 'perf report', then
the same explanation in the previous cset applies.
An additional example uses a pair of SDT events available for systemtap:
# perf probe --exec=/usr/bin/stap '%*:*'
Added new events:
sdt_stap:benchmark__thread__start (on %* in /usr/bin/stap)
sdt_stap:benchmark (on %* in /usr/bin/stap)
sdt_stap:benchmark__thread__end (on %* in /usr/bin/stap)
sdt_stap:pass6__start (on %* in /usr/bin/stap)
sdt_stap:pass6__end (on %* in /usr/bin/stap)
sdt_stap:pass5__start (on %* in /usr/bin/stap)
sdt_stap:pass5__end (on %* in /usr/bin/stap)
sdt_stap:pass0__start (on %* in /usr/bin/stap)
sdt_stap:pass0__end (on %* in /usr/bin/stap)
sdt_stap:pass1a__start (on %* in /usr/bin/stap)
sdt_stap:pass1b__start (on %* in /usr/bin/stap)
sdt_stap:pass1__end (on %* in /usr/bin/stap)
sdt_stap:pass2__start (on %* in /usr/bin/stap)
sdt_stap:pass2__end (on %* in /usr/bin/stap)
sdt_stap:pass3__start (on %* in /usr/bin/stap)
sdt_stap:pass3__end (on %* in /usr/bin/stap)
sdt_stap:pass4__start (on %* in /usr/bin/stap)
sdt_stap:pass4__end (on %* in /usr/bin/stap)
sdt_stap:benchmark__start (on %* in /usr/bin/stap)
sdt_stap:benchmark__end (on %* in /usr/bin/stap)
sdt_stap:cache__get (on %* in /usr/bin/stap)
sdt_stap:cache__clean (on %* in /usr/bin/stap)
sdt_stap:cache__add__module (on %* in /usr/bin/stap)
sdt_stap:cache__add__source (on %* in /usr/bin/stap)
sdt_stap:stap_system__complete (on %* in /usr/bin/stap)
sdt_stap:stap_system__start (on %* in /usr/bin/stap)
sdt_stap:stap_system__spawn (on %* in /usr/bin/stap)
sdt_stap:stap_system__fork (on %* in /usr/bin/stap)
sdt_stap:intern_string (on %* in /usr/bin/stap)
sdt_stap:client__start (on %* in /usr/bin/stap)
sdt_stap:client__end (on %* in /usr/bin/stap)
You can now use it in all perf tools, such as:
perf record -e sdt_stap:client__end -aR sleep 1
#
From these we're use the two below to run systemtap's test suite:
# perf record -e sdt_stap:pass2__*,cycles:P make installcheck > /dev/null
^C[ perf record: Woken up 8 times to write data ]
[ perf record: Captured and wrote 2.691 MB perf.data (39638 samples) ]
Terminated
# perf script | grep sdt_stap
stap 28979 [000] 19424.302660: sdt_stap:pass2__start: (561b9a537de3) arg1=140730364262544
stap 28979 [000] 19424.333083: sdt_stap:pass2__end: (561b9a53a9e1) arg1=140730364262544
stap 29045 [006] 19424.933460: sdt_stap:pass2__start: (563edddcede3) arg1=140722674883152
stap 29045 [006] 19424.963794: sdt_stap:pass2__end: (563edddd19e1) arg1=140722674883152
# perf script | grep cycles | wc -l
39634
#
Looking at the whole perf.data file:
[root@quaco testsuite]# perf report | grep cycles:P -A25
# Samples: 39K of event 'cycles:P'
# Event count (approx.): 34044267368
#
# Overhead Command Shared Object Symbol
# ........ ....... .................... ................................
#
3.50% cc1 cc1 [.] ht_lookup_with_hash
3.04% cc1 cc1 [.] _cpp_lex_token
2.11% cc1 cc1 [.] ggc_internal_alloc
1.83% cc1 cc1 [.] cpp_get_token_with_location
1.68% cc1 libc-2.29.so [.] _int_malloc
1.41% cc1 cc1 [.] linemap_position_for_column
1.25% cc1 cc1 [.] ggc_internal_cleared_alloc
1.20% cc1 cc1 [.] c_lex_with_flags
1.18% cc1 cc1 [.] get_combined_adhoc_loc
1.05% cc1 libc-2.29.so [.] malloc
1.01% cc1 libc-2.29.so [.] _int_free
0.96% stap stap [.] std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::allocator<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Identity, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, stringtable_hash, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, true, true> >::_M_insert<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, true> > > >
0.78% stap stap [.] lexer::scan
0.74% cc1 cc1 [.] _cpp_lex_direct
0.70% cc1 cc1 [.] pop_scope
0.70% cc1 cc1 [.] c_parser_declspecs
0.69% stap libc-2.29.so [.] _int_malloc
0.68% cc1 cc1 [.] htab_find_slot
0.68% cc1 [kernel.vmlinux] [k] prepare_exit_to_usermode
0.64% cc1 [kernel.vmlinux] [k] clear_page_erms
[root@quaco testsuite]#
And now only what happens in slices demarcated by those start/end SDT
events:
[root@quaco testsuite]# perf report --switch-on=sdt_stap:pass2__start --switch-off=sdt_stap:pass2__end | grep cycles:P -A100
# Samples: 240 of event 'cycles:P'
# Event count (approx.): 206491934
#
# Overhead Command Shared Object Symbol
# ........ ....... ................... ................................................
#
38.99% stap stap [.] systemtap_session::register_library_aliases
19.47% stap stap [.] match_key::operator<
15.01% stap libc-2.29.so [.] __memcmp_avx2_movbe
5.19% stap libc-2.29.so [.] _int_malloc
2.50% stap libstdc++.so.6.0.26 [.] std::_Rb_tree_insert_and_rebalance
2.30% stap stap [.] match_node::build_no_more
2.07% stap libc-2.29.so [.] malloc
1.66% stap stap [.] std::_Rb_tree<match_key, std::pair<match_key const, match_node*>, std::_Select1st<std::pair<match_key const, match_node*> >, std::less<match_key>, std::allocator<std::pair<match_key const, match_node*> > >::find
1.66% stap stap [.] match_node::bind
1.58% stap [kernel.vmlinux] [k] prepare_exit_to_usermode
1.17% stap [kernel.vmlinux] [k] native_irq_return_iret
0.87% stap stap [.] 0x0000000000032ec4
0.77% stap libstdc++.so.6.0.26 [.] std::_Rb_tree_increment
0.47% stap stap [.] std::vector<derived_probe_builder*, std::allocator<derived_probe_builder*> >::_M_realloc_insert<derived_probe_builder* const&>
0.47% stap [kernel.vmlinux] [k] get_page_from_freelist
0.47% stap [kernel.vmlinux] [k] swapgs_restore_regs_and_return_to_usermode
0.47% stap [kernel.vmlinux] [k] do_user_addr_fault
0.46% stap [kernel.vmlinux] [k] __pagevec_lru_add_fn
0.46% stap stap [.] std::_Rb_tree<match_key, std::pair<match_key const, match_node*>, std::_Select1st<std::pair<match_key const, match_node*> >, std::less<match_key>, std::allocator<std::pair<match_key const, match_node*> > >::_M_emplace_unique<std::pair<match_key, match_node*> >
0.42% stap libstdc++.so.6.0.26 [.] 0x00000000000c18fa
0.40% stap [kernel.vmlinux] [k] interrupt_entry
0.40% stap [kernel.vmlinux] [k] update_load_avg
0.40% stap [kernel.vmlinux] [k] __intel_pmu_disable_all
0.40% stap [kernel.vmlinux] [k] clear_page_erms
0.39% stap [kernel.vmlinux] [k] __mod_node_page_state
0.39% stap [kernel.vmlinux] [k] error_entry
0.39% stap [kernel.vmlinux] [k] sync_regs
0.38% stap [kernel.vmlinux] [k] __handle_mm_fault
0.38% stap stap [.] derive_probes
#
# (Tip: System-wide collection from all CPUs: perf record -a)
#
[root@quaco testsuite]#
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: William Cohen <wcohen@redhat.com>
Link: https://lkml.kernel.org/n/tip-408hvumcnyn93a0auihnawew@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.