[Bug breakpoints/28288] New: gdbserver close connection

[Bug breakpoints/28288] New: gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

            Bug ID: 28288
           Summary: gdbserver close connection
           Product: gdb
           Version: 8.2.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: breakpoints
          Assignee: unassigned at sourceware dot org
          Reporter: massimiliano.cuoghi at systemceramics dot com
  Target Milestone: ---

I have a problem when i'm in remote debugging. I use QtCreator 4.15.0, and qt
version 5.15.2. Linux = Debian GNU/Linux 10 (buster).
When i'm debugging stopped on a breakpoint (only in this case) and i'm
debugging step by step after a while the application dies, this seems to be
caused by using QProcess in threads parallel to the thread where i'm debugging.
I think it is a problem with the gdbserver that in the debug window it shows
the following message: "Can't detemine the currente address space of thread
Thread xxxxx A problem internal to GDB has been detected, further debugging may
prove unreliable." and after close the connection.
But I have no idea how to fix it. Gdb Server version 8.2.1 and it was
configured for "x86_64-linux-gnu".

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |simark at simark dot ca

--- Comment #1 from Simon Marchi <simark at simark dot ca> ---
Hi,

GDB(server) 8.2 is quite old.  Could you please try with the latest snapshot of
GDB 11 (which is soon to be released)?

https://sourceware.org/pub/gdb/snapshots/branch/?C=M;O=D

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #2 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
I think the latest version of gdb does not compile on debian10, the debian 10
distribution only makes it available up to gdb 8.2.1, now I do a test

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #3 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
I have the follow error in debian10:

/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing makeinfo
--split-size=5000000 --split-size=5000000   -I ./../../readline/readline/doc -I
./../mi -I . \
        -o gdb.info ./gdb.texinfo
/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing: 81:
/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing: makeinfo: not
found
WARNING: 'makeinfo' is missing on your system.
         You should only need it if you modified a '.texi' file, or
         any other file indirectly affecting the aspect of the manual.
         You might want to install the Texinfo package:
         <http://www.gnu.org/software/texinfo/>
         The spurious makeinfo call might also be the consequence of
         using a buggy 'make' (AIX, DU, IRIX), in which case you might
         want to install GNU make:
         <http://www.gnu.org/software/make/>
make[4]: *** [Makefile:491: gdb.info] Error 127
make[4]: Leaving directory
'/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/gdb/doc'
make[3]: *** [Makefile:1974: subdir_do] Error 1
make[3]: Leaving directory
'/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/gdb'
make[2]: *** [Makefile:1640: all] Error 2
make[2]: Leaving directory
'/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/gdb'
make[1]: *** [Makefile:10450: all-gdb] Error 2
make[1]: Leaving directory
'/mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830'
make: *** [Makefile:903: all] Error 2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #4 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
I did the same test with gdb 10 and DEbian unstable it gives me a different
error, but the result is the same. with gdb 11 on debian10 it doesn't get to
the end of make but it generates the executables, by replacing the executables
of gdb and gdbserver gives me the same error of gdb 10

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #5 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
THe error with gdb10 and 11 is 

>&"Remote 'g' packet reply is too long (expected 560 bytes, got 2416 bytes): 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\n"
>&"p

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #6 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13638
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13638&action=edit
testcase

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #7 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13639
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13639&action=edit
log

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #8 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13640
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13640&action=edit
log 8.2.1

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #9 from Simon Marchi <simark at simark dot ca> ---
(In reply to Massimiliano from comment #3)
> I have the follow error in debian10:
> 
> /mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing makeinfo
> --split-size=5000000 --split-size=5000000   -I ./../../readline/readline/doc
> -I ./../mi -I . \
> 	-o gdb.info ./gdb.texinfo
> /mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing: 81:
> /mnt/hgfs/ScambioLinux/gdbserver/gdb-11.0.90.20210830/missing: makeinfo: not
> found
> WARNING: 'makeinfo' is missing on your system.

You are missing the "makeinfo" tool.  Using Debian's package tracker, you can
find that this is provided by the "texinfo" package:

https://packages.debian.org/search?suite=buster&arch=any&mode=path&searchon=contents&keywords=makeinfo

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #10 from Simon Marchi <simark at simark dot ca> ---
(In reply to Massimiliano from comment #6)
> Created attachment 13638 [details]
> testcase

Thanks, can you please provide the commands required to compile the test case,
and then the GDB commands required to reach the bug?  If you can, start your
GDB with the "-nx" switch to avoid loading any gdbinit file.  That makes it
easier to reproduce on our side, as sometimes people have some setting in their
gdbinit that isn't mentioned but is important for the reproduction of the bug.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #11 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
I am not very practical to use the gdb or to compile on the command line
because I usually use the qtcreator that gives it all. However I add a new
testcase "testcasenew" made by me. with the instructions of how I did to
generate the problem:

1) to compile go to the testcasenew directory and give the following commands:
     - qmake untitled.pro
     - qmake
     - make

2) Copy the executable to the target and after I have given:
     - gdbserver localhost: 2000 testcase

3) On the host machine
     - gdb -nx testcase
     - remote target 192.168.127.172:2000
     - b main
     - break main.cpp: 33

4) then give the following command until it goes into error
     - continue

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #12 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13643
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13643&action=edit
New test case

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

Massimiliano <massimiliano.cuoghi at systemceramics dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #13638|0                           |1
        is obsolete|                            |
  Attachment #13643|0                           |1
        is obsolete|                            |

--- Comment #13 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13644
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13644&action=edit
New test case

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #14 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13645
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13645&action=edit
Screenshot

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

Massimiliano <massimiliano.cuoghi at systemceramics dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
  Attachment #13644|0                           |1
        is obsolete|                            |

--- Comment #15 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13646
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13646&action=edit
test new case

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] gdbserver close connection

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #16 from Simon Marchi <simark at simark dot ca> ---
Ok, I reproduced:

(gdb) 
Continuing.
[Detaching after fork from child process 2096323]
[New inferior 2]
Reading /home/simark/Downloads/testcasenew/testcase from remote target...
Reading /home/simark/Downloads/testcasenew/testcase from remote target...
Reading symbols from target:/home/simark/Downloads/testcasenew/testcase...
[New Thread 2096324.2096324]
[Switching to Thread 2096324.2096324]
Remote 'g' packet reply is too long (expected 560 bytes, got 816 bytes):
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

I have seen this issue, I have a patch that fixes at least part of that, but I
did not have time to test it properly and submit it.  It is here for now:

https://review.lttng.org/c/binutils-gdb/+/6187

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|gdbserver close connection  |GDBserver should hide
                   |                            |unreported fork childs from
                   |                            |thread lists

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #17 from Simon Marchi <simark at simark dot ca> ---
This was discussed a while ago:

https://sourceware.org/pipermail/gdb-patches/2016-June/133906.html

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #18 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Simon Marchi from comment #16)
> Ok, I reproduced:
> 
> (gdb) 
> Continuing.
> [Detaching after fork from child process 2096323]
> [New inferior 2]
> Reading /home/simark/Downloads/testcasenew/testcase from remote target...
> Reading /home/simark/Downloads/testcasenew/testcase from remote target...
> Reading symbols from target:/home/simark/Downloads/testcasenew/testcase...
> [New Thread 2096324.2096324]
> [Switching to Thread 2096324.2096324]
> Remote 'g' packet reply is too long (expected 560 bytes, got 816 bytes):
> 000000000000000000000000000000008d315df7ff7f00004075e7f3ff7f00000000000000000
> 0001110000000000000004a00e4ff7f00003875e7f3ff7f00000000000000000000d075e7f3ff
> 7f0000000000000000000046020000000000000100000000000000cc75e7f3ff7f00000000000
> 000000000104e00e4ff7f00008d315df7ff7f000046020000330000002b000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 000000000000000000000000007f03000000000000ffff0000000000000000000000000000000
> 00000000000002f7573722f62696e2f77686f616d69002f7573722f62696e2f77686f616d6900
> 2f002f002f002f002f002f002f002f002f002f000000000000000000000000002929292929292
> 92929292929292929291026d3f7ff7f00000026d3f7ff7f000004000000140100000000000000
> 00000000000000000000000000000000000000697465282900315f715f7374617274750000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 000000000000000000000000000000000000000000000000000000000000000801f0000380000
> 00000000004086e7f3ff7f0000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 00000000000000000000000000000000000000000000000000000000000000000000000000000
> 000000000000000
> 
> I have seen this issue, I have a patch that fixes at least part of that, but
> I did not have time to test it properly and submit it.  It is here for now:
> 
> https://review.lttng.org/c/binutils-gdb/+/6187

I'm testing the change at the moment it seems to work much better

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #19 from Simon Marchi <simark at simark dot ca> ---
> I'm testing the change at the moment it seems to work much better

Thanks for testing, that's good to know.  I will eventually get to re-checking
the patch and submitting it upstream.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #20 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Simon Marchi from comment #19)
> > I'm testing the change at the moment it seems to work much better
> 
> Thanks for testing, that's good to know.  I will eventually get to
> re-checking the patch and submitting it upstream.

I did some tests, I saw that it is much more stable but I also saw that it is
slower, did you have time to do some tests?

I wanted to know if the change is confirmed for the new gdb.

thanks

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #21 from Simon Marchi <simark at simark dot ca> ---
Is it the patch I gave you that makes things slower, or a newer GDB versus an
older GDB?  Do you have a specific scenario I could test to see the performance
difference?

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #22 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Simon Marchi from comment #21)
> Is it the patch I gave you that makes things slower, or a newer GDB versus
> an older GDB?  Do you have a specific scenario I could test to see the
> performance difference?

i did the test using qtcreator. gdbserver 8.2.1 is very fast to do "Step Over"
while from gdb11 for the same operation it takes 5 seconds, so I can say that
it is not a problem of the patch, because I tried the patch with version 12.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #23 from Simon Marchi <simark at simark dot ca> ---
If feasible, could you try to share a reproducer and the commands that give you
that "slow step"?  I'd be interested in digging a little bit.

In the mean time, I have posted the patches related to this bug a few days ago:

https://sourceware.org/pipermail/gdb-patches/2021-October/182922.html

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

Simon Marchi <simark at simark dot ca> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-11-05
             Status|UNCONFIRMED                 |WAITING

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #24 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Simon Marchi from comment #23)
> If feasible, could you try to share a reproducer and the commands that give
> you that "slow step"?  I'd be interested in digging a little bit.
> 
> In the mean time, I have posted the patches related to this bug a few days
> ago:
> 
> https://sourceware.org/pipermail/gdb-patches/2021-October/182922.html

unfortunately i can't reproduce the problem using the command line with a small
example, i see it with my program which is very big using qtcreator, i wouldn't
want it to be qtcreator's fault. 

it can also be seen using a small program, but the effect is much less, but on
the command line I don't know how to show it. practically in the debug window
with local variables this always takes a while to update the value of the
variables when you are stopped on a break.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #25 from Simon Marchi <simark at simark dot ca> ---
If you can give some steps to reproduce using qtcreator, I could give it a try.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #26 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13773
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13773&action=edit
debug gdb  8.2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #27 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13774
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13774&action=edit
debug gdb 12

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #28 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Massimiliano from comment #27)
> Created attachment 13774 [details]
> debug gdb 12


I have attached two videos of what I mean, where you can see how the variables
update more slowly in the debug window. there are the two versions compared, I
go to the debug menu and press step over.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #29 from Simon Marchi <simark at simark dot ca> ---
I see.  It could be the process of updating all the varobjs that takes time. 
If possible, could you attach the MI logs of both sessions?  It's supposed to
be possible to get them in QtCreator:

https://myprogrammingnotes.com/qt-creator-interact-debugger-gdb.html

If that log did show timestamps, it would be helpful, as we could get an idea
of what takes time.  But just seeing which commands QtCreator uses here would
be helpful.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #30 from Simon Marchi <simark at simark dot ca> ---
Just asking to verify, so we can rule this out: are your 2 GDBs built the same
way?  By default the build system doesn't enable optimizations (AFAIK), so if
your GDB 8.2 comes from some distribution, it might be optimized, and if you
built your own GDB 11 / 12, it might not.

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #31 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13779
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13779&action=edit
congif log gdb 8.2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #32 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13780
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13780&action=edit
config log gdb 11

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #33 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13781
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13781&action=edit
log qtcreator gdb 8.2 1/2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #34 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13782
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13782&action=edit
log qtcreator gdb 8.2 2/2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #35 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13783
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13783&action=edit
log qtcreator gdb 11 1/2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #36 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
Created attachment 13784
  --> https://sourceware.org/bugzilla/attachment.cgi?id=13784&action=edit
log qtcreator gdb 11 2/2

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #37 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Massimiliano from comment #36)
> Created attachment 13784 [details]
> log qtcreator gdb 11 2/2

I had already tried looking at the qtcreator logs (which I have attached) with
no particular success. I have also attached the logs of the two compilations of
gdb 8.2 and 11

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[simark at simark dot ca]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #38 from Simon Marchi <simark at simark dot ca> ---
For whether your GDB 11 build is optimized... I see some -O2 in the config.log.
 But to be sure, go in the gdb/ directory and do "make clean && make V=1".  If
you see -O2 on the command line, that's good.

The steps that seems to take time is this one.  With GDB 8 (1-2 seconds):

10:19:12.918
6362python
theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":"100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,"formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,"qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,"token":6362,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":"watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":"657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":"68526573756c74","iname":"watch.3"},{"exp":"697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":"6c69737442617254797065","iname":"watch.5"},{"exp":"6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":"6d6f64656c496e666f","iname":"watch.7"},{"exp":"6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":"706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":"706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":"76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.12"}]})
10:19:14.229

With GDB 11 (~12 seconds):

11:22:22.323 [1ms]
6462python
theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":"100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,"formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,"qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,"token":6462,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":"watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":"657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":"68526573756c74","iname":"watch.3"},{"exp":"697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":"6c69737442617254797065","iname":"watch.5"},{"exp":"6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":"6d6f64656c496e666f","iname":"watch.7"},{"exp":"6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":"706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":"706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":"76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.12"}]})
11:22:34.311

That seems to be a Python helper used by QtCreator to dump variables.  It might
be possible to reproduce the slowness out of QtCreator by running to the same
point, and doing a similar call to theDumper.fetchVariables.

Do you see the same slowness if you debug locally instead of remotely?

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #39 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Simon Marchi from comment #38)
> For whether your GDB 11 build is optimized... I see some -O2 in the
> config.log.  But to be sure, go in the gdb/ directory and do "make clean &&
> make V=1".  If you see -O2 on the command line, that's good.
> 
> The steps that seems to take time is this one.  With GDB 8 (1-2 seconds):
> 
> 10:19:12.918
> 6362python
> theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":
> "100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,
> "formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,
> "qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,
> "token":6362,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":
> "watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":
> "657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":
> "68526573756c74","iname":"watch.3"},{"exp":
> "697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":
> "6c69737442617254797065","iname":"watch.5"},{"exp":
> "6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":
> "6d6f64656c496e666f","iname":"watch.7"},{"exp":
> "6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":
> "706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":
> "706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":
> "76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.
> 12"}]})
> 10:19:14.229
> 
> With GDB 11 (~12 seconds):
> 
> 11:22:22.323 [1ms]
> 6462python
> theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":
> "100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,
> "formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,
> "qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,
> "token":6462,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":
> "watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":
> "657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":
> "68526573756c74","iname":"watch.3"},{"exp":
> "697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":
> "6c69737442617254797065","iname":"watch.5"},{"exp":
> "6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":
> "6d6f64656c496e666f","iname":"watch.7"},{"exp":
> "6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":
> "706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":
> "706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":
> "76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.
> 12"}]})
> 11:22:34.311
> 
> That seems to be a Python helper used by QtCreator to dump variables.  It
> might be possible to reproduce the slowness out of QtCreator by running to
> the same point, and doing a similar call to theDumper.fetchVariables.
> 
> Do you see the same slowness if you debug locally instead of remotely?

I had already checked the -o2 option and also in my opinion it is already
optimized, even doing "make clean && make V = 1" does not change anything. i
have the same problem using the gdb11 locally

-- 
You are receiving this mail because:
You are on the CC list for the bug.

[Bug breakpoints/28288] GDBserver should hide unreported fork childs from thread lists

[massimiliano.cuoghi at systemceramics dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=28288

--- Comment #40 from Massimiliano <massimiliano.cuoghi at systemceramics dot com> ---
(In reply to Massimiliano from comment #39)
> (In reply to Simon Marchi from comment #38)
> > For whether your GDB 11 build is optimized... I see some -O2 in the
> > config.log.  But to be sure, go in the gdb/ directory and do "make clean &&
> > make V=1".  If you see -O2 on the command line, that's good.
> > 
> > The steps that seems to take time is this one.  With GDB 8 (1-2 seconds):
> > 
> > 10:19:12.918
> > 6362python
> > theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":
> > "100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,
> > "formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,
> > "qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,
> > "token":6362,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":
> > "watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":
> > "657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":
> > "68526573756c74","iname":"watch.3"},{"exp":
> > "697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":
> > "6c69737442617254797065","iname":"watch.5"},{"exp":
> > "6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":
> > "6d6f64656c496e666f","iname":"watch.7"},{"exp":
> > "6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":
> > "706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":
> > "706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":
> > "76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.
> > 12"}]})
> > 10:19:14.229
> > 
> > With GDB 11 (~12 seconds):
> > 
> > 11:22:22.323 [1ms]
> > 6462python
> > theDumper.fetchVariables({"autoderef":0,"context":"","displaystringlimit":
> > "100","dyntype":1,"expanded":["watch","local","inspect","return"],"fancy":1,
> > "formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,
> > "qobjectnames":1,"resultvarname":"","stringcutoff":"10000","timestamps":1,
> > "token":6462,"typeformats":{},"watchers":[{"exp":"6472697665724964","iname":
> > "watch.0"},{"exp":"64737044726976657248617368","iname":"watch.1"},{"exp":
> > "657468496e666f726d6174696f6e48617368","iname":"watch.2"},{"exp":
> > "68526573756c74","iname":"watch.3"},{"exp":
> > "697041647272657373416e644e65746d61736b","iname":"watch.4"},{"exp":
> > "6c69737442617254797065","iname":"watch.5"},{"exp":
> > "6d61704d6f64756c61724d616368696e65496e666f","iname":"watch.6"},{"exp":
> > "6d6f64656c496e666f","iname":"watch.7"},{"exp":
> > "6d6f64656c6c6f5374616d70616e7465","iname":"watch.8"},{"exp":
> > "706172616d65746572546f436f6e76657274","iname":"watch.9"},{"exp":
> > "706172616d6574657273546f4265436f6e766572746564","iname":"watch.10"},{"exp":
> > "76616c7565","iname":"watch.11"},{"exp":"76617248617368","iname":"watch.
> > 12"}]})
> > 11:22:34.311
> > 
> > That seems to be a Python helper used by QtCreator to dump variables.  It
> > might be possible to reproduce the slowness out of QtCreator by running to
> > the same point, and doing a similar call to theDumper.fetchVariables.
> > 
> > Do you see the same slowness if you debug locally instead of remotely?
> 
> I had already checked the -o2 option and also in my opinion it is already
> optimized, even doing "make clean && make V = 1" does not change anything. i
> have the same problem using the gdb11 locally

I also tried a different linux distribution, the distribution included the
gdb10, I didn't have to recompile it, it has the same slowness defect

-- 
You are receiving this mail because:
You are on the CC list for the bug.