BMC/Intel-BMC/linux.git/tools/perf/util/event.c, branch dev-5.0

perf tools: Allow specifying proc-map-timeout in config file

2018-12-17T17:56:57+00:00

The default timeout of 500ms for parsing /proc//maps files is too short for profiling many of our services. This can be overridden by passing --proc-map-timeout to the relevant command but it'd be nice to globally increase our default value. This patch permits setting a different default with the core.proc-map-timeout config file parameter. Signed-off-by: Mark Drayton Acked-by: Song Liu Acked-by: Namhyung Kim Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20181204203420.1683114-1-mbd@fb.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use fallback for sample_addr_correlates_sym() cases

2018-12-17T17:54:16+00:00

thread__resolve() is used in the sample_addr_correlates_sym() cases where 'addr' is a destination of a branch which does not necessarily have the same cpumode as the 'ip'. Use the fallback function in that case. This patch depends on patch "perf tools: Add fallback functions for cases where cpumode is insufficient". Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: David S. Miller Cc: Jiri Olsa Cc: Leo Yan Cc: Mathieu Poirier Cc: stable@vger.kernel.org # 4.19 Link: http://lkml.kernel.org/r/20181106210712.12098-3-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf thread: Add fallback functions for cases where cpumode is insufficient

2018-12-17T17:54:13+00:00

For branch stacks or branch samples, the sample cpumode might not be correct because it applies only to the sample 'ip' and not necessary to 'addr' or branch stack addresses. Add fallback functions that can be used to deal with those cases Signed-off-by: Adrian Hunter Cc: Andi Kleen Cc: David S. Miller Cc: Jiri Olsa Cc: Leo Yan Cc: Mathieu Poirier Cc: stable@vger.kernel.org # 4.19 Link: http://lkml.kernel.org/r/20181106210712.12098-2-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Don't clone maps from parent when synthesizing forks

2018-10-31T13:18:01+00:00

When synthesizing FORK events, we are trying to create thread objects for the already running tasks on the machine. Normally, for a kernel FORK event, we want to clone the parent's maps because that is what the kernel just did. But when synthesizing, this should not be done. If we do, we end up with overlapping maps as we process the sythesized MMAP2 events that get delivered shortly thereafter. Use the FORK event misc flags in an internal way to signal this situation, so we can elide the map clone when appropriate. Signed-off-by: David S. Miller Cc: Don Zickus Cc: Jiri Olsa Cc: Joe Mario Link: http://lkml.kernel.org/r/20181030.222404.2085088822877051075.davem@davemloft.net [ Added comment about flag use in machine__process_fork_event(), use ternary op in thread__clone_map_groups() as suggested by Jiri ] Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Stop fallbacking to kallsyms for vdso symbols lookup

2018-10-17T18:56:15+00:00

David reports that: Perf has this hack where it uses the kernel symbol map as a backup when a symbol can't be found in the user's symbol table(s). This causes problems because the tests driving this code path use machine__kernel_ip(), and that is completely meaningless on Sparc. On sparc64 the kernel and user live in physically separate virtual address spaces, rather than a shared one. And the kernel lives at a virtual address that overlaps common userspace addresses. So this test passes almost all the time when a user symbol lookup fails. The consequence of this is that, if the unfound user virtual address in the sample doesn't match up to a kernel symbol either, we trigger things like this code in builtin-top.c: if (al.sym == NULL && al.map != NULL) { const char *msg = "Kernel samples will not be resolved.\n"; /* * As we do lazy loading of symtabs we only will know if the * specified vmlinux file is invalid when we actually have a * hit in kernel space and then try to load it. So if we get * here and there are _no_ symbols in the DSO backing the * kernel map, bail out. * * We may never get here, for instance, if we use -K/ * --hide-kernel-symbols, even if the user specifies an * invalid --vmlinux ;-) */ if (!machine->kptr_restrict_warned && !top->vmlinux_warned && __map__is_kernel(al.map) && map__has_symbols(al.map)) { if (symbol_conf.vmlinux_name) { char serr[256]; dso__strerror_load(al.map->dso, serr, sizeof(serr)); ui__warning("The %s file can't be used: %s\n%s", symbol_conf.vmlinux_name, serr, msg); } else { ui__warning("A vmlinux file was not found.\n%s", msg); } if (use_browser <= 0) sleep(5); top->vmlinux_warned = true; } } When I fire up a compilation on sparc, this triggers immediately. I'm trying to figure out what the "backup to kernel map" code is accomplishing. I see some language in the current code and in the changes that have happened in this area talking about vdso. Does that really happen? The vdso is mapped into userspace virtual addresses, not kernel ones. More history. This didn't cause problems on sparc some time ago, because the kernel IP check used to be "ip < 0" :-) Sparc kernel addresses are not negative. But now with machine__kernel_ip(), which works using the symbol table determined kernel address range, it does trigger. What it all boils down to is that on architectures like sparc, machine__kernel_ip() should always return false in this scenerio, and therefore this kind of logic: if (cpumode == PERF_RECORD_MISC_USER && machine && mg != &machine->kmaps && machine__kernel_ip(machine, al->addr)) { is basically invalid. PERF_RECORD_MISC_USER implies no kernel address can possibly match for the sample/event in question (no matter how hard you try!) :-) So, I thought something had changed and in the past we would somehow find that address in the kallsyms, but I couldn't find anything to back that up, the patch introducing this is over a decade old, lots of things changed, so I was just thinking I was missing something. I tried a gtod busy loop to generate vdso activity and added a 'perf probe' at that branch, on x86_64 to see if it ever gets hit: Made thread__find_map() noinline, as 'perf probe' in lines of inline functions seems to not be working, only at function start. (Masami?) # perf probe -x ~/bin/perf -L thread__find_map:57 57 if (cpumode == PERF_RECORD_MISC_USER && machine && 58 mg != &machine->kmaps && 59 machine__kernel_ip(machine, al->addr)) { 60 mg = &machine->kmaps; 61 load_map = true; 62 goto try_again; } } else { /* * Kernel maps might be changed when loading * symbols so loading * must be done prior to using kernel maps. */ 69 if (load_map) 70 map__load(al->map); 71 al->addr = al->map->map_ip(al->map, al->addr); # perf probe -x ~/bin/perf thread__find_map:60 Added new event: probe_perf:thread__find_map (on thread__find_map:60 in /home/acme/bin/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:thread__find_map -aR sleep 1 # Then used this to see if, system wide, those probe points were being hit: # perf trace -e *perf:thread*/max-stack=8/ ^C[root@jouet ~]# No hits when running 'perf top' and: # cat gtod.c #include int main(void) { struct timeval tv; while (1) gettimeofday(&tv, 0); return 0; } [root@jouet c]# ./gtod ^C Pressed 'P' in 'perf top' and the [vdso] samples are there: 62.84% [vdso] [.] __vdso_gettimeofday 8.13% gtod [.] main 7.51% [vdso] [.] 0x0000000000000914 5.78% [vdso] [.] 0x0000000000000917 5.43% gtod [.] _init 2.71% [vdso] [.] 0x000000000000092d 0.35% [kernel] [k] native_io_delay 0.33% libc-2.26.so [.] __memmove_avx_unaligned_erms 0.20% [vdso] [.] 0x000000000000091d 0.17% [i2c_i801] [k] i801_access 0.06% firefox [.] free 0.06% libglib-2.0.so.0.5400.3 [.] g_source_iter_next 0.05% [vdso] [.] 0x0000000000000919 0.05% libpthread-2.26.so [.] __pthread_mutex_lock 0.05% libpixman-1.so.0.34.0 [.] 0x000000000006d3a7 0.04% [kernel] [k] entry_SYSCALL_64_trampoline 0.04% libxul.so [.] style::dom_apis::query_selector_slow 0.04% [kernel] [k] module_get_kallsym 0.04% firefox [.] malloc 0.04% [vdso] [.] 0x0000000000000910 I added a 'perf probe' to thread__find_map:69, and that surely got tons of hits, i.e. for every map found, just to make sure the 'perf probe' command was really working. In the process I noticed a bug, we're only have records for '[vdso]' for pre-existing commands, i.e. ones that are running when we start 'perf top', when we will generate the PERF_RECORD_MMAP by looking at /perf/PID/maps. I.e. like this, for preexisting processes with a vdso map, again, tracing for all the system, only pre-existing processes get a [vdso] map (when having one): [root@jouet ~]# perf probe -x ~/bin/perf __machine__addnew_vdso Added new event: probe_perf:__machine__addnew_vdso (on __machine__addnew_vdso in /home/acme/bin/perf) You can now use it in all perf tools, such as: perf record -e probe_perf:__machine__addnew_vdso -aR sleep 1 [root@jouet ~]# perf trace -e probe_perf:__machine__addnew_vdso/max-stack=8/ 0.000 probe_perf:__machine__addnew_vdso:(568eb3) __machine__addnew_vdso (/home/acme/bin/perf) map__new (/home/acme/bin/perf) machine__process_mmap2_event (/home/acme/bin/perf) machine__process_event (/home/acme/bin/perf) perf_event__process (/home/acme/bin/perf) perf_tool__process_synth_event (/home/acme/bin/perf) perf_event__synthesize_mmap_events (/home/acme/bin/perf) __event__synthesize_thread (/home/acme/bin/perf) The kernel is generating a PERF_RECORD_MMAP for vDSOs, but somehow 'perf top' is not getting those records while 'perf record' is: # perf record ~acme/c/gtod ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.076 MB perf.data (1499 samples) ] # perf report -D | grep PERF_RECORD_MMAP2 71293612401913 0x11b48 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x400000(0x1000) @ 0 fd:02 1137 541179306]: r-xp /home/acme/c/gtod 71293612419012 0x11be0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a2783000(0x227000) @ 0 fd:00 3146370 854107250]: r-xp /usr/lib64/ld-2.26.so 71293612432110 0x11c50 [0x60]: PERF_RECORD_MMAP2 25484/25484: [0x7ffcdb53a000(0x2000) @ 0 00:00 0 0]: r-xp [vdso] 71293612509944 0x11cb0 [0x70]: PERF_RECORD_MMAP2 25484/25484: [0x7fa4a23cd000(0x3b6000) @ 0 fd:00 3149723 262067164]: r-xp /usr/lib64/libc-2.26.so # # perf script | grep vdso | head gtod 25484 71293.612768: 2485554 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso]) gtod 25484 71293.613576: 2149343 cycles:ppp: 7ffcdb53a917 [unknown] ([vdso]) gtod 25484 71293.614274: 1814652 cycles:ppp: 7ffcdb53aca8 __vdso_gettimeofday+0x98 ([vdso]) gtod 25484 71293.614862: 1669070 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso]) gtod 25484 71293.615404: 1451589 cycles:ppp: 7ffcdb53acc5 __vdso_gettimeofday+0xb5 ([vdso]) gtod 25484 71293.615999: 1269941 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) gtod 25484 71293.616405: 1177946 cycles:ppp: 7ffcdb53a914 [unknown] ([vdso]) gtod 25484 71293.616775: 1121290 cycles:ppp: 7ffcdb53ac47 __vdso_gettimeofday+0x37 ([vdso]) gtod 25484 71293.617150: 1037721 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) gtod 25484 71293.617478: 994526 cycles:ppp: 7ffcdb53ace6 __vdso_gettimeofday+0xd6 ([vdso]) # The patch is the obvious one and with it we also continue to resolve vdso symbols for pre-existing processes in 'perf top' and for all processes in 'perf record' + 'perf report/script'. Suggested-by: David Miller Acked-by: David Miller Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-cs7skq9pp0kjypiju6o7trse@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf cpu_map: Align cpu map synthesized events properly.

2018-10-16T15:30:03+00:00

The size of the resulting cpu map can be smaller than a multiple of sizeof(u64), resulting in SIGBUS on cpus like Sparc as the next event will not be aligned properly. Signed-off-by: David S. Miller Cc: Jiri Olsa Cc: Kan Liang Fixes: 6c872901af07 ("perf cpu_map: Add cpu_map event synthesize function") Link: http://lkml.kernel.org/r/20181011.224655.716771175766946817.davem@davemloft.net Signed-off-by: Arnaldo Carvalho de Melo

perf map: Synthesize maps only for thread group leader

2018-08-08T18:55:59+00:00

Threads share map_groups, all map events are merged into it. Thus we could send mmaps only for thread group leader. Otherwise it took ages to attach and record something from processes with many vmas and threads. Thread group leader could be already dead, but it seems perf cannot handle this case anyway. Testing dummy: #include #include #include #include #include void *thread(void *arg) { pause(); } int main(int argc, char **argv) { int threads = 10000; int vmas = 50000; pthread_t th; for (int i = 0; i < threads; i++) pthread_create(&th, NULL, thread, NULL); for (int i = 0; i < vmas; i++) mmap(NULL, 4096, (i & 1) ? PROT_READ : PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0); sleep(60); return 0; } Comment by Jiri Olsa: We actualy synthesize the group leader (if we found one) for the thread even if it's not present in the thread_map, so the process maps are always in data. Signed-off-by: Konstantin Khlebnikov Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/153363294102.396323.6277944760215058174.stgit@buzz Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Synthesize and process mmap events for x86 PTI entry trampolines

2018-05-23T13:26:39+00:00

Like the kernel text, the location of x86 PTI entry trampolines must be recorded in the perf.data file. Like the kernel, synthesize a mmap event for that, and add processing for it. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1526986485-6562-10-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf machine: Allow for extra kernel maps

2018-05-22T13:59:22+00:00

Identify extra kernel maps by name so that they can be distinguished from the kernel map and module maps. Signed-off-by: Adrian Hunter Cc: Alexander Shishkin Cc: Andi Kleen Cc: Andy Lutomirski Cc: Dave Hansen Cc: H. Peter Anvin Cc: Jiri Olsa Cc: Joerg Roedel Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1526986485-6562-8-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf symbols: Unify symbol maps

2018-04-27T13:47:06+00:00

Remove the split of symbol tables for data (MAP__VARIABLE) and for functions (MAP__FUNCTION), its unneeded and there were various places doing two lookups to find a symbol, so simplify this. We still will consider only the symbols that matched the filters in place, i.e. see the (elf_(sec,sym)|symbol_type)__filter() routines in the patch, just so that we consider only the same symbols as before, to reduce the possibility of regressions. All the tests on 50-something build environments, in varios versions of lots of distros and cross build environments were performed without build regressions, as usual with all pull requests the other tests were also performed: 'perf test' and 'make -C tools/perf build-test'. Also this was done at a great granularity so that regressions can be bisected more easily. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: https://lkml.kernel.org/n/tip-hiq0fy2rsleupnqqwuojo1ne@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo