Re: Noted slowness in profile loading with binutils 2.37

[Alexander Lindsay <alexlindsay239@gmail.com>]

Hi Nick,

This was the result of my bisect:

ca8f6bc629cb27792ce449e7253c74a3f6f75fda is the first bad commit
Date:   Tue Mar 2 16:08:23 2021 +0000

    Fix the BFD library's parsing of DIEs where specification attributes
can refer to variables that are defined later on.

            PR 27484
            * dwarf2.c (scan_unit_for_symbols): Scan twice, once to
accumulate
            function and variable tags and a second time to resolve their
            attributes.

 bfd/ChangeLog |   7 ++++
 bfd/dwarf2.c  | 133
++++++++++++++++++++++++++++++++++++++++++++++------------
 2 files changed, 114 insertions(+), 26 deletions(-)

On Thu, Feb 10, 2022 at 3:00 AM Nick Clifton <nickc@redhat.com> wrote:

> Hi Alexander,
>
> > - binutils version 2.36.1: 6.5 seconds
> > - binutils version 2.37: Still not loaded at 6 minutes
> >
> > I think the relevant binutil tool here is addr2line. Does anyone have a
> > quick idea for what may have caused the slow-down?
>
> It will be a change in the BFD library.  More specifically it
> is likely to be a change to bfd/dwarf2.c.  Have a look at the
> ChangeLog in the bfd/ directory for the 2.37 release for more
> hints.
>
> I suspect, but do not know for sure, that it could be the patch
> for PR 27484 ....
>
> Cheers
>    Nick
>
>
>