From: Mathieu Desnoyers via Libc-alpha <libc-alpha@sourceware.org>
To: Florian Weimer <fweimer@redhat.com>
Cc: libc-alpha <libc-alpha@sourceware.org>,
Joseph Myers <joseph@codesourcery.com>
Subject: Re: [PATCH glibc 3/3] rseq registration tests (v10)
Date: Wed, 27 May 2020 11:05:32 -0400 (EDT) [thread overview]
Message-ID: <1975648335.36785.1590591932673.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <1647263261.34186.1590504195448.JavaMail.zimbra@efficios.com>
----- On May 26, 2020, at 10:43 AM, Mathieu Desnoyers mathieu.desnoyers@efficios.com wrote:
> ----- On May 26, 2020, at 8:47 AM, Florian Weimer fweimer@redhat.com wrote:
>
>> * Mathieu Desnoyers:
[...]
The one question below is the last thing we need to complete discussing
before I can re-spin another version of the patches:
>>
>>>>> + retpid = TEMP_FAILURE_RETRY (waitpid (pid, &status, 0));
>>>>> + if (retpid != pid)
>>>>> + {
>>>>> + FAIL_EXIT1 ("waitpid returned %ld, expected %ld",
>>>>> + (long int) retpid, (long int) pid);
>>>>> + }
>>>>
>>>> Hmm. Is the TEMP_FAILURE_RETRY really needed? Our xwaitpid does not
>>>> have this.
>>>
>>> Then how does it deal with a signal interrupting the system call performing
>>> the waitpid (EINTR) ? I do not see WNOHANG being used.
>>
>> It obscures spurious signals. In most test cases, if an unexpected
>> signal is delivered, something is quite wrong indeed. This is why we
>> don't generally hide EINTR errors.
>
> So it means you may have trouble using tools like strace and gdb on those
> tests ? AFAIU those are heavy users of SIGSTOP and SIGCONT. Similarly for
> profilers, those usually rely on a timer-driven signal.
>
Should I use xwaitpid instead, and should xwaitpid be fixed to use
TEMP_FAILURE_RETRY ?
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2020-05-27 15:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-01 2:14 [PATCH glibc 0/3] Restartable Sequences enablement Mathieu Desnoyers via Libc-alpha
2020-05-01 2:14 ` [PATCH glibc 1/3] glibc: Perform rseq registration at C startup and thread creation (v19) Mathieu Desnoyers via Libc-alpha
2020-05-20 11:40 ` Florian Weimer via Libc-alpha
2020-05-25 14:51 ` Mathieu Desnoyers via Libc-alpha
2020-05-25 15:20 ` Florian Weimer via Libc-alpha
2020-05-25 17:36 ` Mathieu Desnoyers via Libc-alpha
2020-05-26 12:41 ` Florian Weimer via Libc-alpha
2020-05-26 14:32 ` Mathieu Desnoyers via Libc-alpha
2020-05-26 14:38 ` Florian Weimer via Libc-alpha
2020-05-26 14:53 ` Mathieu Desnoyers via Libc-alpha
2020-05-26 14:57 ` Florian Weimer via Libc-alpha
2020-05-26 15:22 ` Mathieu Desnoyers via Libc-alpha
2020-05-01 2:14 ` [PATCH glibc 2/3] glibc: sched_getcpu(): use rseq cpu_id TLS on Linux (v7) Mathieu Desnoyers via Libc-alpha
2020-05-20 10:14 ` Florian Weimer via Libc-alpha
2020-05-01 2:14 ` [PATCH glibc 3/3] rseq registration tests (v10) Mathieu Desnoyers via Libc-alpha
2020-05-20 10:52 ` Florian Weimer via Libc-alpha
2020-05-25 17:07 ` Mathieu Desnoyers via Libc-alpha
2020-05-26 12:47 ` Florian Weimer via Libc-alpha
2020-05-26 14:43 ` Mathieu Desnoyers via Libc-alpha
2020-05-27 15:05 ` Mathieu Desnoyers via Libc-alpha [this message]
2020-05-27 15:12 ` Florian Weimer via Libc-alpha
2020-05-27 15:17 ` Mathieu Desnoyers via Libc-alpha
2020-05-27 15:21 ` Florian Weimer via Libc-alpha
2020-05-27 15:30 ` Mathieu Desnoyers via Libc-alpha
2020-05-20 11:44 ` [PATCH glibc 0/3] Restartable Sequences enablement Florian Weimer via Libc-alpha
2020-05-25 13:52 ` Mathieu Desnoyers via Libc-alpha
2020-05-25 14:28 ` Florian Weimer via Libc-alpha
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