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From: Richard Weinberger <richard@nod.at>
To: linux-kernel@vger.kernel.org
Cc: user-mode-linux-devel@lists.sourceforge.net
Subject: gcc-4.6.0 generates no code for sub_preempt_count()
Date: Wed, 13 Apr 2011 21:50:05 +0200	[thread overview]
Message-ID: <201104132150.05623.richard@nod.at> (raw)

Hi,

I'm facing a very strange issue with gcc-4.6.0 and UML.
Within __local_bh_enable() gcc generates no code for sub_preempt_count().

See:
http://userweb.kernel.org/~rw/uml-gcc460/__local_bh_enable-gcc460.txt
vs.
http://userweb.kernel.org/~rw/uml-gcc460/__local_bh_enable-gcc431.txt

Interestingly it generates code for add_preempt_count().
I can reproduce this on x86 and x86_64.

The problem has to do with UML's current_thread_info() function.
When I replace it with arch/x86's (unportable) variant gcc generates code.

Any ideas whether this is a gcc or a kernel issue?
Thanks,
//richard

             reply	other threads:[~2011-04-13 19:50 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-13 19:50 Richard Weinberger [this message]
2011-04-14  7:49 ` gcc-4.6.0 generates no code for sub_preempt_count() Mikael Pettersson
2011-04-14 13:52   ` Richard Weinberger
2011-04-14 19:50     ` [uml-devel] " James McMechan
2011-04-14 19:50       ` James McMechan
2011-04-15 15:17       ` Richard Weinberger
2011-04-14 14:43 ` masterkom masterkom
2011-04-14 15:17   ` Frank Kingswood

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