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Date:   Fri, 15 Jun 2018 13:50:17 -0400 (EDT)
From:   Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To:     Florian Weimer <fweimer@redhat.com>
Cc:     Pavel Machek <pavel@ucw.cz>, carlos <carlos@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        libc-alpha <libc-alpha@sourceware.org>
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Subject: Re: Restartable Sequences system call merged into Linux
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Thread-Topic: Restartable Sequences system call merged into Linux
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----- On Jun 15, 2018, at 1:09 AM, Florian Weimer fweimer@redhat.com wrote:

> On 06/14/2018 03:01 PM, Mathieu Desnoyers wrote:
>> Another alternative would be to somehow let glibc handle the registration,
>> perhaps only doing it for applications expressing their interest for rseq.
> 
> That's not really possible.  We can't rely on the visibility of symbol
> bindings due to lazy binding and hidden visibility.  Registration of
> intent by other means will not work because if it is done from user
> code, some other library may have already launched a thread at this point.
> 
> (It's also a moot point if we want to use restartable sequences in glibc
> itself.)

Considering that we can expect the glibc memory allocator to benefit from
rseq to speed up its memory allocator, this means pretty much any application
linked against glibc *will* end up using rseq indirectly.

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com