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SubjectRe: [GIT PULL] perf/urgent fixes

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Em Mon, Oct 21, 2019 at 08:23:54AM +0200, Ingo Molnar escreveu:
> > 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.
>
> I couldn't reproduce this one so far, with another small function,
> clear_page_erms, what happens is that the cursor seems to be hidden at the
> bottom, if you press the "magic" 'D' hotkey it will tell (at the bottom of the
> screen) that the idx is at 18, which for a function with just 8 output lines
> doesn't make sense:
>
> Samples: 12K of event 'cycles', 4000 Hz, Event count (approx.): 2219443843
> clear_page_erms /proc/kcore [Percent: local period]
> Percent│ ◆
> │ ▒
> │ ▒
> │ Disassembly of section load0: ▒
> │ ▒
> │ ffffffffab9d17c0 <load0>: ▒
> │ mov $0x1000,%ecx ▒
> │ xor %eax,%eax ▒
> 100.00 │ rep stos %al,%es:(%rdi) ▒
> │ ← retq ▒
> ▒
> 1: nr_ent=20, height=35, idx=18, top_idx=1, nr_asm_entries=8
>
> Doesn't make sense, there aren't 20 entries nor the idx is 18, the
> nr_asm_entries is right, I'll try to follow up on this one...
>
> But you can in these cases try to go on pressin the up arrow till the cursor
> appears, etc.

Yeah, I can reproduce this too - and don't see the original weirdness
anymore. :-/

Will re-report if it happens again.

Thanks,

Ingo

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