From: Florian Weimer <fw@deneb.enyo.de>
To: "Robert Święcki" <robert@swiecki.net>
Cc: GLIBC Devel <libc-alpha@sourceware.org>,
Adhemerval Zanella <adhemerval.zanella@linaro.org>
Subject: Re: Caching of PID/TID after fork
Date: Sun, 09 Oct 2016 10:05:00 -0000 [thread overview]
Message-ID: <87mvidj0qw.fsf@mid.deneb.enyo.de> (raw)
In-Reply-To: <CAP145phqU29-vMNkS6zzWRJn4L_F9+zHQkybiirQndBcxJGp8g@mail.gmail.com> ("Robert \=\?utf-8\?B\?xZp3acSZY2tpIidz\?\= message of "Fri, 7 Oct 2016 23:23:19 +0200")
* Robert Święcki:
>> The other question I have is whether we talk about clone-as-fork
>> exclusively. Introducing a new thread into the process on which
>> non-free-standing code can run using clone is a different matter
>> altogether.
>
> To my knowledge, in the vast majority of cases (or even, in all
> cases), where the TID/PID caching problem surfaced, it could have been
> solved by fork_with_flags() indeed.
So no new thread? Good.
> Though, one useful feature which could be potentially useful for some
> porjects would be to create a detached process (for which the kernel
> doesn't send termination signal - usually SIGCHLD - to the parent
> process). And this cannot be solved by ORing custom flags with fork
> ones, because SIGCHLD is already there. But, it's just a guess.
Yes, I know of some cases where this would have helped as well.
If we go the fork-with-flags route, we should translate glibc-specific
flags to kernel flags anyway because the kernel might introduce new
flags which break the interface in subtle ways (see O_TMPFILE and mode
argument handling).
next prev parent reply other threads:[~2016-10-09 10:05 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-06 16:13 Robert Święcki
2016-10-06 16:34 ` Paul Pluzhnikov
2016-10-06 17:03 ` Robert Święcki
2016-10-06 18:32 ` Adhemerval Zanella
2016-10-06 17:26 ` Rich Felker
2016-10-06 17:42 ` Robert Święcki
2016-10-06 18:05 ` Rich Felker
2016-10-06 18:26 ` Robert Święcki
2016-10-06 21:35 ` Robert Święcki
2016-10-07 0:42 ` Zack Weinberg
2016-10-07 0:43 ` Zack Weinberg
2016-10-07 14:44 ` Robert Święcki
2016-10-07 18:20 ` Adhemerval Zanella
2016-10-07 18:30 ` Adhemerval Zanella
2016-10-07 19:38 ` Florian Weimer
2016-10-07 21:23 ` Robert Święcki
2016-10-09 10:05 ` Florian Weimer [this message]
2016-10-09 14:19 ` Robert Święcki
2016-10-10 18:03 ` Adhemerval Zanella
2016-11-04 15:14 ` Florian Weimer
2016-11-04 16:03 ` Adhemerval Zanella
2016-11-07 16:04 ` Florian Weimer
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