Subject: Re: [RFC PATCH v6 1/5] Thread-local ABI system call: cache CPU number
 of running thread
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        "H. Peter Anvin" <hpa@zytor.com>
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Cc: Andrew Morton <akpm@linux-foundation.org>,
        Russell King <linux@arm.linux.org.uk>,
        Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@redhat.com>,
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        Josh Triplett <josh@joshtriplett.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will.deacon@arm.com>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>
From: Florian Weimer <fweimer@redhat.com>
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Date: Tue, 5 Apr 2016 18:02:25 +0200
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On 04/04/2016 10:48 PM, Mathieu Desnoyers wrote:

> Moreover, the feature set that the application knows about, glibc
> knows about, and the kernel knows about are three different things.
> My intent here is to have glibc stay out of the way as much as possible,
> since this is really an interface between various applications/libraries
> and the kernel.

Surely glibc can allocate the space based on what is advertised as
needed by the kernel?  Why would it limit itself to what is supported by
the kernel headers it is compiled against if the actual size can be
queried from the kernel?

Florian