Re: Two observations using GDB 13 snapshot

Tom Tromey
2022-12-19T21:19:17Z

>>>>> "Eli" == Eli Zaretskii via Gdb-patches <gdb-patches@sourceware.org> writes:

Eli> Tom, could you please chime in? What could explain such a slowdown
Eli> using -readnow and in the MinGW build without worker threads (since
Eli> GDB 12 didn't use threads, either)? And why -readnow is so different
Eli> from a GDB built without threading?

Just a quick answer for now, I haven't tried to reproduce or
investigate...

-readnow should not really be affected by the DWARF scanner rewrite.
With -readnow, all the new code is bypassed anyway. For quite a while
now, -readnow (when using DWARF anyway) has operated on the principle
that since gdb is reading full symbols, it might as well not bother with
partial symbols (or now, the index).

Threads also should not matter here, because only the initial scan can
use multiple threads. The full symbol reader is single-threaded and
hasn't changed in any deep way since GDB 12.

It's possible that some other change affected this -- the DWARF reader
in general sees a lot of patches. I don't know which one it might be
offhand, though.

Tom