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5ea0416f51
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Milian Wolff 5ea0416f51 perf report: Include partial stacks unwound with libdw 
So far the whole stack was thrown away when any error occurred before
the maximum stack depth was unwound. This is actually a very common
scenario though. The stacks that got unwound so far are still
interesting. This removes a large chunk of differences when comparing
perf script output for libunwind and libdw perf unwinding.

E.g. with libunwind:

~~~~~
heaptrack_gui  2228 135073.388524:     479408 cycles:
        ffffffff811749ed perf_iterate_ctx ([kernel.kallsyms])
        ffffffff81181662 perf_event_mmap ([kernel.kallsyms])
        ffffffff811cf5ed mmap_region ([kernel.kallsyms])
        ffffffff811cfe6b do_mmap ([kernel.kallsyms])
        ffffffff811b0dca vm_mmap_pgoff ([kernel.kallsyms])
        ffffffff811cdb0c sys_mmap_pgoff ([kernel.kallsyms])
        ffffffff81033acb sys_mmap ([kernel.kallsyms])
        ffffffff81631d37 entry_SYSCALL_64_fastpath ([kernel.kallsyms])
                   192ca mmap64 (/usr/lib/ld-2.25.so)
                    59a9 _dl_map_object_from_fd (/usr/lib/ld-2.25.so)
                    83d0 _dl_map_object (/usr/lib/ld-2.25.so)
                    cda1 openaux (/usr/lib/ld-2.25.so)
                   1834f _dl_catch_error (/usr/lib/ld-2.25.so)
                    cfe2 _dl_map_object_deps (/usr/lib/ld-2.25.so)
                    3481 dl_main (/usr/lib/ld-2.25.so)
                   17387 _dl_sysdep_start (/usr/lib/ld-2.25.so)
                    4d37 _dl_start (/usr/lib/ld-2.25.so)
                     d87 _start (/usr/lib/ld-2.25.so)

heaptrack_gui  2228 135073.388677:     611329 cycles:
                   1a3e0 strcmp (/usr/lib/ld-2.25.so)
                    82b2 _dl_map_object (/usr/lib/ld-2.25.so)
                    cda1 openaux (/usr/lib/ld-2.25.so)
                   1834f _dl_catch_error (/usr/lib/ld-2.25.so)
                    cfe2 _dl_map_object_deps (/usr/lib/ld-2.25.so)
                    3481 dl_main (/usr/lib/ld-2.25.so)
                   17387 _dl_sysdep_start (/usr/lib/ld-2.25.so)
                    4d37 _dl_start (/usr/lib/ld-2.25.so)
                     d87 _start (/usr/lib/ld-2.25.so)
~~~~~

With libdw without this patch:

~~~~~
heaptrack_gui  2228 135073.388524:     479408 cycles:
        ffffffff811749ed perf_iterate_ctx ([kernel.kallsyms])
        ffffffff81181662 perf_event_mmap ([kernel.kallsyms])
        ffffffff811cf5ed mmap_region ([kernel.kallsyms])
        ffffffff811cfe6b do_mmap ([kernel.kallsyms])
        ffffffff811b0dca vm_mmap_pgoff ([kernel.kallsyms])
        ffffffff811cdb0c sys_mmap_pgoff ([kernel.kallsyms])
        ffffffff81033acb sys_mmap ([kernel.kallsyms])
        ffffffff81631d37 entry_SYSCALL_64_fastpath ([kernel.kallsyms])

heaptrack_gui  2228 135073.388677:     611329 cycles:
~~~~~

With this patch applied, the libdw unwinder will produce the same
output as the libunwind unwinder.

Signed-off-by: Milian Wolff <milian.wolff@kdab.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/20170601210021.20046-1-milian.wolff@kdab.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-06-05 14:18:03 -03:00
..
accounting
arch tools/include: Sync kernel ABI headers with tooling headers 2017-05-24 09:00:21 +02:00
build Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-15 15:50:49 -07:00
cgroup
firewire
gpio gpio-hammer: fix make consumer_label suitable to work on gpio-nails 2017-01-26 16:29:09 +01:00
hv tools: hv: Add clean up function for Ubuntu config 2017-03-06 17:10:40 -08:00
iio iio: Add channel for Gravity 2017-01-05 13:02:25 +00:00
include tools/include: Sync kernel ABI headers with tooling headers 2017-05-24 09:00:21 +02:00
kvm/kvm_stat tools/kvm_stat: add '%Total' column 2017-03-29 12:01:33 +02:00
laptop
leds tools/leds: Add led_hw_brightness_mon program 2017-02-14 22:20:23 +01:00
lguest Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-01 20:51:12 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-15 15:50:49 -07:00
net tools: bpf_jit_disasm: Add option to dump JIT image to a file. 2017-04-13 13:04:03 -04:00
nfsd
objtool objtool: Drop ARRAY_SIZE() definition, tools/include/linux/kernel.h has it now 2017-04-19 13:01:44 -03:00
pci tools: PCI: Add sample test script to invoke pcitest 2017-04-28 10:23:20 -05:00
pcmcia
perf perf report: Include partial stacks unwound with libdw 2017-06-05 14:18:03 -03:00
power Merge branches 'acpi-button' and 'acpi-tools' 2017-05-22 20:29:06 +02:00
scripts tools arch x86: Include asm/cmpxchg.h 2017-03-03 19:07:13 -03:00
spi spi: spidev_test: add option to continuously transfer data 2017-03-21 18:44:40 +00:00
testing This fixes a bug caused by not cleaning up the new instance unique triggers 2017-05-20 23:39:03 -07:00
thermal/tmon
time
usb usb: fix some references for /proc/bus/usb 2017-04-18 16:54:19 +02:00
virtio tools/virtio: fix spelling mistake: "wakeus" -> "wakeups" 2017-05-09 16:43:24 +03:00
vm tools/vm: add missing Makefile rules 2017-02-22 16:41:26 -08:00
Makefile tools/kvm: fix top level makefile 2017-05-03 16:30:25 +02:00