From: Rainer Orth <ro@CeBiTec.Uni-Bielefeld.DE>
To: Joel Brobecker <brobecker@adacore.com>
Cc: gdb-patches@sourceware.org
Subject: Re: GDB 10.1 release: branching early July?
Date: Tue, 16 Jun 2020 15:49:43 +0200 [thread overview]
Message-ID: <ydd7dw7ce88.fsf@CeBiTec.Uni-Bielefeld.DE> (raw)
In-Reply-To: <20200615230959.GJ7711@adacore.com> (Joel Brobecker's message of "Mon, 15 Jun 2020 16:09:59 -0700")
Hi Joel,
>> > * [RainerO]
>> > <PR gdb/25939> [10 regression] run fails with ICE on Solaris
>> >
>> > Not sure if this is still an issue or not. Rainer did push some
>> > patches to master back in May. To be confirmed.
>>
>> unfortunately, it is, and I didn't have much success debugging it. This
>> makes gdb useless on Solaris and was introduced by the multi-target
>> merge. I'm completely unfamiliar with that code and will need all the
>> help I can get to get this resolved.
>
> Boooo... Understood. Maybe start a dedicated discussion on gdb-patches
> with your current findings? Maybe Pedro can give you some pointers,
> to help us debug and fix this thing?
I guess that's the only option: at the glacial rate I'm currently making
progress, a patch will be ready for GDB 11 at the earliest otherwise.
> I see that you've already provided a bit of information in the PR
> itself (https://sourceware.org/bugzilla/show_bug.cgi?id=25939), but
> perhaps we could start with a summary of the situation, and what
> you have found so far? For instance, IIUC, this affects debugging
> of any program on Solaris. Are you still getting the same error?
I've got to try that first, but assuming that the problem is in procfs.c
(and maybe sol-thread.c), it's unlikely to have gone away in the
meantime.
> Your observation about a large number of threads being created is
> interesting, and perhaps deserves to be dug into a little deeper,
> considering that you think this wasn't happening with a version
> prior to the multitarget patch series?
I've now found where those are coming from: the thread name "gdb worker"
visible in ps -L provided the necessary clue. They are due to worker
threads now being enabled by default. On my desktop with 4 cores and
hyperthreading, that's relatively harmless. However, when I run gdb on
an 8-socket server with 160 cores total, the messages about thread
creation when debugging gdb are killing you ;-) I traced this to
maint.c (update_thread_pool_size) where the count defaults to
std::thread::hardware_concurrency (). Maybe a bit over-eager...
Rainer
--
-----------------------------------------------------------------------------
Rainer Orth, Center for Biotechnology, Bielefeld University
next prev parent reply other threads:[~2020-06-16 13:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-14 1:56 Joel Brobecker
2020-06-14 2:04 ` Simon Marchi
2020-06-15 22:53 ` Joel Brobecker
2020-06-18 19:57 ` Pedro Alves
2020-06-14 15:14 ` Rainer Orth
2020-06-15 23:09 ` Joel Brobecker
2020-06-16 13:49 ` Rainer Orth [this message]
2020-06-16 18:13 ` Joel Brobecker
2020-06-14 15:32 ` Hannes Domani
2020-06-15 23:17 ` Joel Brobecker
2020-06-16 20:28 ` Tom Tromey
2020-06-14 16:53 ` Philippe Waroquiers
2020-06-14 16:57 ` Philippe Waroquiers
2020-06-16 0:13 ` Joel Brobecker
2020-06-26 11:36 ` Luis Machado
2020-06-26 16:26 ` Joel Brobecker
2020-06-26 19:27 ` Luis Machado
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