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Date:   Thu, 3 May 2018 14:04:24 -0400 (EDT)
From:   Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To:     Daniel Colascione <dancol@google.com>
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Subject: Re: [RFC PATCH for 4.18 00/14] Restartable Sequences
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----- On May 3, 2018, at 12:22 PM, Daniel Colascione dancol@google.com wrote:

> On Thu, May 3, 2018 at 9:12 AM Mathieu Desnoyers <
> mathieu.desnoyers@efficios.com> wrote:
>> By the way, if we eventually find a way to enhance user-space mutexes in
> the
>> fashion you describe here, it would belong to another TLS area, and would
>> be registered by another system call than rseq. I proposed a more generic
>> "TLS area registration" system call a few years ago, but Linus told me he
>> wanted a system call that was specific to rseq. If we need to implement
>> other use-cases in a TLS area shared between kernel and user-space in a
>> similar fashion, the plan is to do it in a distinct system call.
> 
> If we proliferate TLS areas; we'd have to register each one upon thread
> creation, adding to the overall thread creation path. There's already a
> provision for versioning the TLS area. What's the benefit of splitting the
> registration over multiple system calls?

See the original discussion thread at

https://lkml.org/lkml/2016/4/7/502

Thanks,

Mathieu

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