From: Yao Qi <qiyaoltc@gmail.com>
To: Pedro Alves <palves@redhat.com>
Cc: Sergio Durigan Junior <sergiodj@redhat.com>,
Yao Qi <qiyaoltc@gmail.com>,
gdb-patches@sourceware.org
Subject: Re: [PATCH v3 00/23] All-stop on top of non-stop
Date: Tue, 21 Apr 2015 07:48:00 -0000 [thread overview]
Message-ID: <86r3rdzzvc.fsf@gmail.com> (raw)
In-Reply-To: <553526D0.9030802@redhat.com> (Pedro Alves's message of "Mon, 20 Apr 2015 17:18:24 +0100")
Pedro Alves <palves@redhat.com> writes:
> I assume you mean you saw this once, and if that if you rerun that
> test in particular, the fail goes away.
No, I saw these fails very time I run this single test.
>
>> Note that there is no regression either on
>>> aarch64 GNU/Linux with gdbserver.
>
> Awesome.
>
>>>
>>> (gdb) info threads^M
>>> Id Target Id Frame ^M
>>> ...
>>> 30 Thread 0x2019dff1f0 (LWP 28308) "joinable" 0x0000002000121a68
>>> in clone () from /lib/aarch64-linux-gnu/libc.so.6^
>>> ...
>>> GPT: lwp Thread 0x2019dff1f0 (LWP 28308) has no pending signal^M
>>> Can't detach Thread 0x2019dff1f0 (LWP 28308): No such process^
>>> (gdb) FAIL: gdb.threads/attach-many-short-lived-threads.exp: iter 1:
>>> detach
>>>
>>> Another race problem on attach/detach?
>
> I think so, yes. The same race that was fixed for regular
> resumes, here:
>
> https://sourceware.org/ml/gdb-patches/2015-03/msg00597.html
>
> can easily happen when detaching. Say, you have 2 threads in your
> program. GDB must detach from each thread individually. So it
> starts by detaching from thread 1. And just before detaching
> from thread 2, thread 1 causes the whole process to exit. So
> the PTRACE_DETACH for thread 2 errors with ESRCH (No such process.)
>
> Now I don't know is why you would see that on iteration 1 ("iter 1").
> One possibility could be that a thread that has already been
> detached crashed the process, because e.g., GDB left breakpoints
> inserted in memory by mistake, or something is wrong with
> infrun.c:prepare_for_detach, or something else along those lines.
> In that case, assuming "ulimit -c unlimited", you'll probably find you have
> a core dump for the crashing inferior.
Thanks for the clue. I'll dig it deeper. I'll read these patches
today, if I don't see any new problems or questions, these patches are
fine to me.
--
Yao (齐尧)
next prev parent reply other threads:[~2015-04-21 7:48 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-17 10:47 Pedro Alves
2015-04-17 10:45 ` [PATCH v3 08/17] Factor out code to re-resume stepped thread Pedro Alves
2015-04-17 10:45 ` [PATCH v3 11/17] Fix signal-while-stepping-over-bp-other-thread.exp on targets always in non-stop Pedro Alves
2015-04-17 10:45 ` [PATCH v3 05/17] Embed the pending step-over chain in thread_info objects Pedro Alves
2015-04-21 8:28 ` Yao Qi
2015-04-22 20:14 ` Pedro Alves
2015-04-21 9:53 ` Yao Qi
2015-04-22 19:07 ` Pedro Alves
2015-04-22 4:25 ` Doug Evans
2015-04-22 22:19 ` Pedro Alves
2015-04-17 10:45 ` [PATCH v3 15/17] PPC64: Fix gdb.arch/ppc64-atomic-inst.exp with displaced stepping Pedro Alves
2015-04-21 11:21 ` Yao Qi
2015-04-22 20:04 ` Pedro Alves
2015-04-17 10:45 ` [PATCH v3 02/17] Change adjust_pc_after_break's prototype Pedro Alves
2015-04-17 10:45 ` [PATCH v3 06/17] Use keep_going in proceed and start_step_over too Pedro Alves
2015-04-22 5:09 ` Doug Evans
2015-04-22 22:22 ` Pedro Alves
2015-04-17 10:45 ` [PATCH v3 13/17] Fix step-over-{trips-on-watchpoint|lands-on-breakpoint}.exp race Pedro Alves
2015-04-17 10:45 ` [PATCH v3 03/17] remote.c/all-stop: Implement TARGET_WAITKIND_NO_RESUMED and TARGET_WNOHANG Pedro Alves
2015-04-17 10:45 ` [PATCH v3 04/17] Make thread_still_needs_step_over consider stepping_over_watchpoint too Pedro Alves
2015-04-17 10:47 ` [PATCH v3 17/17] native Linux: enable always non-stop by default Pedro Alves
2015-04-17 10:47 ` [PATCH v3 07/17] Misc switch_back_to_stepped_thread cleanups Pedro Alves
2015-04-21 9:50 ` Yao Qi
2015-04-22 20:04 ` Pedro Alves
2015-04-22 5:23 ` Doug Evans
2015-04-22 20:05 ` Pedro Alves
2015-04-28 20:28 ` Doug Evans
2015-04-17 10:47 ` [PATCH v3 01/17] Fix and test "checkpoint" in non-stop mode Pedro Alves
2015-04-21 2:36 ` Doug Evans
2015-04-22 17:48 ` Pedro Alves
2015-04-28 18:18 ` Doug Evans
2015-04-29 4:56 ` Doug Evans
2015-05-19 18:08 ` Pedro Alves
2015-04-17 10:52 ` [PATCH v3 09/17] Teach non-stop to do in-line step-overs (stop all, step, restart) Pedro Alves
2015-04-17 11:01 ` Pedro Alves
2015-04-21 15:01 ` Yao Qi
2015-04-22 20:03 ` Pedro Alves
2015-04-24 9:06 ` Yao Qi
2015-04-27 20:17 ` Doug Evans
2015-05-19 18:09 ` Pedro Alves
2015-05-19 18:49 ` Pedro Alves
2015-04-17 10:52 ` [PATCH v3 12/17] Fix interrupt-noterm.exp on targets always in non-stop Pedro Alves
2015-04-21 11:40 ` Yao Qi
2015-04-22 20:03 ` Pedro Alves
2015-04-17 10:56 ` [PATCH v3 14/17] Disable displaced stepping if trying it fails Pedro Alves
2015-04-17 11:06 ` [PATCH v3 16/17] S/390: displaced stepping and PC-relative RIL-b/RIL-c instructions Pedro Alves
2015-04-17 11:38 ` [PATCH v3 10/17] Implement all-stop on top of a target running non-stop mode Pedro Alves
2015-04-21 11:09 ` Yao Qi
2015-04-22 20:16 ` Pedro Alves
2015-04-24 7:39 ` Yao Qi
2015-05-19 18:08 ` Pedro Alves
2015-05-21 9:17 ` Yao Qi
2015-04-20 12:02 ` [PATCH v3 00/23] All-stop on top of non-stop Yao Qi
2015-04-20 16:54 ` Sergio Durigan Junior
2015-04-20 16:43 ` Pedro Alves
2015-04-21 7:48 ` Yao Qi [this message]
2015-04-21 15:05 ` Yao Qi
2015-04-22 22:27 ` Pedro Alves
2015-04-20 17:35 ` Simon Marchi
2015-05-19 18:14 ` Pedro Alves
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