Messages in this thread | | | From | Arnaldo Carvalho de Melo <> | Date | Mon, 21 Oct 2019 09:20:28 -0300 | Subject | Re: [GIT PULL] perf/urgent fixes |
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Em Mon, Oct 21, 2019 at 08:23:54AM +0200, Ingo Molnar escreveu: > * Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Please consider pulling,
<SNIP>
> > tools/perf/util/header.c | 4 +++- > > tools/perf/util/util.c | 6 ++++-- > > 12 files changed, 65 insertions(+), 17 deletions(-)
> Pulled, thanks a lot Arnaldo!
Thanks!
> A minor bugreport:
> There's a new nuisance message that I noticed when 'perf top' is started: > a "vmlinux file has not been found" - with a "press any key" - but the > message doesn't actually wait for the keypress, it's cleared on the first > screen refresh...
I'll investigate the problems reported after pushing out the current perf/core lot, thanks for the detailed report!
- Arnaldo
> I'd argue that both the keypress action and the warning message is > superfluous: > > - It annoys users while not actually giving any straightforward way to > fix it. It's displayed on every startup of perf top, which is highly > distracting. > > - At least on Ubuntu it appears to be wrong, because the vmlinux is > available and symbol resolution/annotation appears to be working fine: > > # uname -a > Linux dagon 5.4.0-rc3-custom-00557-gb6c81ae120e0 #1 SMP PREEMPT Sun Oct 20 15:28:00 CEST 2019 x86_64 x86_64 x86_64 GNU/Linux > > # dpkg -l | grep gb6c81ae120e > ii linux-headers-5.4.0-rc3-custom-00557-gb6c81ae120e0 5.4.0-rc3-custom-00557-gb6c81ae120e0-1 amd64 Linux kernel headers for 5.4.0-rc3-custom-00557-gb6c81ae120e0 on amd64 > ii linux-image-5.4.0-rc3-custom-00557-gb6c81ae120e0 5.4.0-rc3-custom-00557-gb6c81ae120e0-1 amd64 Linux kernel, version 5.4.0-rc3-custom-00557-gb6c81ae120e0 > ii linux-image-5.4.0-rc3-custom-00557-gb6c81ae120e0-dbg 5.4.0-rc3-custom-00557-gb6c81ae120e0-1 amd64 Linux kernel debugging symbols for 5.4.0-rc3-custom-00557-gb6c81ae120e0 > ii linux-libc-dev:amd64 5.4.0-rc3-custom-00557-gb6c81ae120e0-1 amd64 Linux support headers for userspace development > > Note that the 'dbg' package is installed which includes the vmlinux, > and perf does seem to find it: > > # dpkg-query -L linux-image-5.4.0-rc3-custom-00557-gb6c81ae120e0-dbg | grep vmlinux$ > /usr/lib/debug/lib/modules/5.4.0-rc3-custom-00557-gb6c81ae120e0/vmlinux > > I can see annotated kernel functions just fine. > > - Finally, when I run perf as root then kallsyms and /proc/kcore is used > to annotate the kernel. So the 'cannot resolve' message cannot even be > true. :-) > > Instead I believe some sort of explanation should be printed in the > natural flow when there's an unknown symbol or someone tries to enter a > kernel symbol that cannot be further resolved. Even there it probably > shouldn't be a 'warning' message, but something printed in-line where > usually we'd see the annotated output - to disrupt the normal workflow as > little as possible. > > Secondly, there also appears to be a TUI weirdness when the annotated > kernel functions are small (or weird): the blue cursor is stuck at the > top and I cannot move between the annotated instructions with the down/up > arrow: > > Samples: 13M of event 'cycles', 4000 Hz, Event count (approx.): 1272420588851 > clear_page_rep /usr/lib/debug/boot/vmlinux-5.4.0-rc3-custom-00557-gb6c81ae120e0 [Percent: local period] > 0.01 │ mov $0x200,%ecx ▒ > │ xorl %eax,%eax ▒ > 0.01 │ xor %eax,%eax ▒ > │ rep stosq ▒ > 99.27 │ rep stos %rax,%es:(%rdi) ▒ > │ ret ▒ > 0.71 │ ← retq > > I can still exit the screen with 'q', and can move around in larger > annotated kernel functions. Not sure whether it's related to function > size, or perhaps to the 'hottest' instruction that the cursor is normally > placed at. > > Thanks, > > Ingo
--
- Arnaldo
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