Em Mon, Oct 21, 2019 at 08:23:54AM +0200, Ingo Molnar escreveu: > * Arnaldo Carvalho de Melo <a...@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
