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Date: Tue, 13 Sep 2016 15:52:18 -0700
From: "Luck, Tony" <tony.luck@intel.com>
To: Dave Hansen <dave.hansen@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        "H. Peter Anvin" <h.peter.anvin@intel.com>,
        Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <peterz@infradead.org>,
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        Ravi V Shankar <ravi.v.shankar@intel.com>,
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        Sai Prakhya <sai.praneeth.prakhya@intel.com>,
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Subject: Re: [PATCH v2 07/33] x86/intel_rdt: Add support for Cache Allocation
 detection
Message-ID: <20160913225217.GA4325@intel.com>
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 <57D88052.60404@intel.com>
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On Tue, Sep 13, 2016 at 03:40:18PM -0700, Dave Hansen wrote:
> Are you sure you don't want to add RDT to disabled-features.h?  You have
> a config option for it, so it seems like you should also be able to
> optimize some of these checks away when the config option is off.

Makefile looks like this:

obj-$(CONFIG_INTEL_RDT)        += intel_rdt.o intel_rdt_rdtgroup.o intel_rdt_schemata.o

which seems to skip compiling all our code when the CONFIG
option is off.

Our hooks to generic code look like:

+#ifdef CONFIG_INTEL_RDT
+extern void rdtgroup_fork(struct task_struct *child);
+extern void rdtgroup_exit(struct task_struct *tsk);
+#else
+static inline void rdtgroup_fork(struct task_struct *child) {}
+static inline void rdtgroup_exit(struct task_struct *tsk) {}
+#endif /* CONFIG_INTEL_RDT */


Does this disabled-features.h thing do something more?

-Tony