public inbox for glibc-bugs@sourceware.org help / color / mirror / Atom feed
From: "luto at mit dot edu" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug nptl/14499] New: Does posix_spawn invoke atfork handlers / use vfork? Date: Mon, 20 Aug 2012 22:24:00 -0000 [thread overview] Message-ID: <bug-14499-131@http.sourceware.org/bugzilla/> (raw) http://sourceware.org/bugzilla/show_bug.cgi?id=14499 Bug #: 14499 Summary: Does posix_spawn invoke atfork handlers / use vfork? Product: glibc Version: unspecified Status: NEW Severity: normal Priority: P2 Component: nptl AssignedTo: unassigned@sourceware.org ReportedBy: luto@mit.edu CC: drepper.fsp@gmail.com Classification: Unclassified The resolution of bug 378 indicates that glibc's (NPTL) posix_spawn calls atfork handlers. This means that posix_spawn can't use vfork (or fancy clone options), which makes it slow. (Note that, AFAICT, this behavior is not documented anywhere, despite being implementation-specified.) This was apparently true when bug 378 was closed, but it changed in commit a9f43ef464f71b0d379524b2a6294092332c9a30. The current behavior is bizarre. See the attached code, which invokes atfork handlers only on the second posix_spawn call. IMO the right fix is to never invoke atfork handlers (since presumably nothing relies on them getting called, since they haven't been reliably called since 2005). That way vfork can be used unconditionally, which is faster. See also bug 10354, which does not have a resolution that I understand. -- Configure bugmail: http://sourceware.org/bugzilla/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
next reply other threads:[~2012-08-20 22:24 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2012-08-20 22:24 luto at mit dot edu [this message] 2012-08-20 22:28 ` [Bug nptl/14499] " luto at mit dot edu 2012-08-21 13:43 ` bugdal at aerifal dot cx 2014-06-17 5:57 ` fweimer at redhat dot com
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=bug-14499-131@http.sourceware.org/bugzilla/ \ --to=sourceware-bugzilla@sourceware.org \ --cc=glibc-bugs@sources.redhat.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).