Message-ID: <49B18B2E.606@us.ibm.com>
Date: Fri, 06 Mar 2009 12:44:30 -0800
From: Darren Hart <dvhltc@us.ibm.com>
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To: Peter Zijlstra <peterz@infradead.org>
CC: Ingo Molnar <mingo@elte.hu>, "lkml, " <linux-kernel@vger.kernel.org>
Subject: Dynamically determine if kernel includes CFS Scheduler
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I've received an internal request for a means to determine at run-time 
if the CFS scheduler is included in the running kernel.  Looking through 
the git commit log and the /proc/sys/kernel filesystem, I think I see 
two approaches:

1) stat("/proc/sys/kernel/sched_compat_yield")
    This confirms 2.6.23-rc7 kernel or later which definitely has the CFS
    scheduler and this functionality is of interest anyway.
2) Test if the kernel version is >= 2.6.22 which is where I believe CFS
    landed.

Any guesses as to how robust/future-proof approach #1 would be?

-- 
Darren Hart
IBM Linux Technology Center
Real-Time Linux Team
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