user/sven/linux.git/tools, branch v4.4.3

perf kvm record/report: 'unprocessable sample' error while recording/reporting guest data

2016-02-25T20:01:20Z

commit 3caeaa562733c4836e61086ec07666635006a787 upstream. 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 54245fdc3576 ("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 Cc: Naveen N. Rao Fixes: 54245fdc3576 ("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 Signed-off-by: Greg Kroah-Hartman

perf tools: tracepoint_error() can receive e=NULL, robustify it

2016-02-25T20:01:16Z

commit ec183d22cc284a7a1e17f0341219d8ec8ca070cc upstream. Fixes segmentation fault using, for instance: (gdb) run record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Starting program: /home/acme/bin/perf record -I -e intel_pt/tsc=1,noretcomp=1/u /bin/ls Missing separate debuginfos, use: dnf debuginfo-install glibc-2.22-7.fc23.x86_64 [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib64/libthread_db.so.1". Program received signal SIGSEGV, Segmentation fault. 0 x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 (gdb) bt #0 0x00000000004b9ea5 in tracepoint_error (e=0x0, err=13, sys=0x19b1370 "sched", name=0x19a5d00 "sched_switch") at util/parse-events.c:410 #1 0x00000000004b9fc5 in add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:433 #2 0x00000000004ba334 in add_tracepoint_event (list=0x19a5d20, idx=0x7fffffffb8c0, sys_name=0x19b1370 "sched", evt_name=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:498 #3 0x00000000004bb699 in parse_events_add_tracepoint (list=0x19a5d20, idx=0x7fffffffb8c0, sys=0x19b1370 "sched", event=0x19a5d00 "sched_switch", err=0x0, head_config=0x0) at util/parse-events.c:936 #4 0x00000000004f6eda in parse_events_parse (_data=0x7fffffffb8b0, scanner=0x19a49d0) at util/parse-events.y:391 #5 0x00000000004bc8e5 in parse_events__scanner (str=0x663ff2 "sched:sched_switch", data=0x7fffffffb8b0, start_token=258) at util/parse-events.c:1361 #6 0x00000000004bca57 in parse_events (evlist=0x19a5220, str=0x663ff2 "sched:sched_switch", err=0x0) at util/parse-events.c:1401 #7 0x0000000000518d5f in perf_evlist__can_select_event (evlist=0x19a3b90, str=0x663ff2 "sched:sched_switch") at util/record.c:253 #8 0x0000000000553c42 in intel_pt_track_switches (evlist=0x19a3b90) at arch/x86/util/intel-pt.c:364 #9 0x00000000005549d1 in intel_pt_recording_options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 ) at arch/x86/util/intel-pt.c:664 #10 0x000000000051e076 in auxtrace_record__options (itr=0x19a2c40, evlist=0x19a3b90, opts=0x8edf68 ) at util/auxtrace.c:539 #11 0x0000000000433368 in cmd_record (argc=1, argv=0x7fffffffde60, prefix=0x0) at builtin-record.c:1264 #12 0x000000000049bec2 in run_builtin (p=0x8fa2a8 , argc=5, argv=0x7fffffffde60) at perf.c:390 #13 0x000000000049c12a in handle_internal_command (argc=5, argv=0x7fffffffde60) at perf.c:451 #14 0x000000000049c278 in run_argv (argcp=0x7fffffffdcbc, argv=0x7fffffffdcb0) at perf.c:495 #15 0x000000000049c60a in main (argc=5, argv=0x7fffffffde60) at perf.c:618 (gdb) Intel PT attempts to find the sched:sched_switch tracepoint but that seg faults if tracefs is not readable, because the error reporting structure is null, as errors are not reported when automatically adding tracepoints. Fix by checking before using. Committer note: This doesn't take place in a kernel that supports perf_event_attr.context_switch, that is the default way that will be used for tracking context switches, only in older kernels, like 4.2, in a machine with Intel PT (e.g. Broadwell) for non-priviledged users. Further info from a similar patch by Wang: The error is in tracepoint_error: it assumes the 'e' parameter is valid. However, there are many situation a parse_event() can be called without parse_events_error. See result of $ grep 'parse_events(.*NULL)' ./tools/perf/ -r' Signed-off-by: Adrian Hunter Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Tong Zhang Cc: Wang Nan Fixes: 196581717d85 ("perf tools: Enhance parsing events tracepoint error output") Link: http://lkml.kernel.org/r/1453809921-24596-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

tools lib traceevent: Fix output of %llu for 64 bit values read on 32 bit machines

2016-02-25T20:01:16Z

commit 32abc2ede536aae52978d6c0a8944eb1df14f460 upstream. When a long value is read on 32 bit machines for 64 bit output, the parsing needs to change "%lu" into "%llu", as the value is read natively. Unfortunately, if "%llu" is already there, the code will add another "l" to it and fail to parse it properly. Signed-off-by: Steven Rostedt Acked-by: Namhyung Kim Link: http://lkml.kernel.org/r/20151116172516.4b79b109@gandalf.local.home Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Greg Kroah-Hartman

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-01-08T21:52:59Z

Pull perf fixes from Ingo Molnar: "Two core subsystem fixes, plus a handful of tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix race in swevent hash perf: Fix race in perf_event_exec() perf list: Robustify event printing routine perf list: Add support for PERF_COUNT_SW_BPF_OUT perf hists browser: Fix segfault if use symbol filter in cmdline perf hists browser: Reset selection when refresh perf hists browser: Add NULL pointer check to prevent crash perf buildid-list: Fix return value of perf buildid-list -k perf buildid-list: Show running kernel build id fix

perf list: Robustify event printing routine

2015-12-16T19:43:10Z

When a43eec304259 ("bpf: introduce bpf_perf_event_output() helper") added PERF_COUNT_SW_BPF_OUTPUT we ended up with a new entry in the event_symbols_sw array that wasn't initialized, thus set to NULL, fix print_symbol_events() to check for that case so that we don't crash if this happens again. (gdb) bt #0 __match_glob (ignore_space=false, pat=, str=) at util/string.c:198 #1 strglobmatch (str=, pat=pat@entry=0x7fffffffe61d "stall") at util/string.c:252 #2 0x00000000004993a5 in print_symbol_events (type=1, syms=0x872880 , max=11, name_only=false, event_glob=0x7fffffffe61d "stall") at util/parse-events.c:1615 #3 print_events (event_glob=event_glob@entry=0x7fffffffe61d "stall", name_only=false) at util/parse-events.c:1675 #4 0x000000000042c79e in cmd_list (argc=1, argv=0x7fffffffe390, prefix=) at builtin-list.c:68 #5 0x00000000004788a5 in run_builtin (p=p@entry=0x871758 , argc=argc@entry=2, argv=argv@entry=0x7fffffffe390) at perf.c:370 #6 0x0000000000420ab0 in handle_internal_command (argv=0x7fffffffe390, argc=2) at perf.c:429 #7 run_argv (argv=0x7fffffffe110, argcp=0x7fffffffe11c) at perf.c:473 #8 main (argc=2, argv=0x7fffffffe390) at perf.c:588 (gdb) p event_symbols_sw[PERF_COUNT_SW_BPF_OUTPUT] $4 = {symbol = 0x0, alias = 0x0} (gdb) A patch to robustify perf to not segfault when the next counter gets added in the kernel will follow this one. Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-57wysblcjfrseb0zg5u7ek10@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf list: Add support for PERF_COUNT_SW_BPF_OUT

2015-12-16T19:43:10Z

When PERF_COUNT_SW_BPF_OUTPUT was added to the kernel we should've added it to tools/perf, where it is used just to list events. This ended up causing a segfault in commands like "perf list stall". Fix it by adding that new software counter. A patch to robustify perf to not segfault when the next counter gets added in the kernel will follow this one. Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Alexei Starovoitov Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-uya354upi3eprsey6mi5962d@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools/virtio: fix byteswap logic

2015-12-07T15:28:10Z

commit cf561f0d2eb74574ad9985a2feab134267a9d298 ("virtio: introduce virtio_is_little_endian() helper") changed byteswap logic to skip feature bit checks for LE platforms, but didn't update tools/virtio, so vring_bench started failing. Update the copy under tools/virtio/ (TODO: find a way to avoid this code duplication). Cc: Greg Kurz Signed-off-by: Michael S. Tsirkin

tools/virtio: move list macro stubs

2015-12-07T15:28:09Z

Makes them more generally available. Signed-off-by: Michael S. Tsirkin

perf hists browser: Fix segfault if use symbol filter in cmdline

2015-12-07T15:02:35Z

If feed perf a symbol filter in cmdline and the result is empty, pressing 'Enter' in the hist browser causes crash: # ./perf report perf.data <-- Common mistake for beginners Then press 'Enter': perf: Segmentation fault -------- backtrace -------- /home/wangnan/perf[0x53e578] /lib64/libc.so.6(+0x3545f)[0x7f76bafe045f] /home/wangnan/perf[0x539dd4] /home/wangnan/perf(perf_evlist__tui_browse_hists+0x96)[0x53d216] /home/wangnan/perf(cmd_report+0x1b9f)[0x442c7f] /home/wangnan/perf[0x47efa2] /home/wangnan/perf(main+0x5f5)[0x432fa5] /lib64/libc.so.6(__libc_start_main+0xf4)[0x7f76bafccbd4] /home/wangnan/perf[0x4330d4] This is because 'perf.data' is interpreted as a symbol filter, and the result is empty, so selection is empty. However, hist_browser__toggle_fold() forgets to check it. This patch simply return false when selection is NULL. Signed-off-by: Wang Nan Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1449455746-41952-2-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf hists browser: Reset selection when refresh

2015-12-07T15:02:12Z

With the following steps: Step 1: perf report Step 2: Use UP/DOWN to select an entry, don't press 'ENTER' Step 3: Use '/' to filter symbols, use a filter which returns empty result Step 4: Press 'ENTER' We see that, even if we have filtered all the symbols (and the main interface is empty), pressing 'ENTER' still selects one symbol. This behavior surprises the user. This patch resets browser->{he_,}selection in hist_browser__refresh() and lets it choose default selection. In this case browser->{he_,}selection keeps NULL so user won't see annotation item in menu. Signed-off-by: Wang Nan Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1449455746-41952-4-git-send-email-wangnan0@huawei.com Signed-off-by: Arnaldo Carvalho de Melo