Re: [PATCH] Only process_die notifier in ia64_do_page_fault if KPROBES is configured.

From: Andi Kleen (ak_at_suse.de)
Date: 08/31/05

  • Next message: Daniel Phillips: "Re: [RFC][PATCH 1 of 4] Configfs is really sysfs" 
    To: "Luck, Tony" <tony.luck@intel.com>
Date:	Wed, 31 Aug 2005 01:38:08 +0200

    On Wednesday 31 August 2005 01:05, Luck, Tony wrote:
    > >Please do not generate any code if the feature cannot ever be
    > >used (CONFIG_KPROBES off). With this patch we still have lots of
    > >unnecessary code being executed on each page fault.
    >
    > I can (eventually) wrap this call inside the #ifdef CONFIG_KPROBES.

    At least the original die notifiers were designed as a generic debugger
    interface, not a kprobes specific thing. So I don't think it's a good idea.
    Given most debuggers don't need the early page fault hook and it's
    mostly needed for a special case in kprobes, but it doesn't seem nice to only
    offer a subset of the hooks with specific config options.

    Also with the inline the test should be essentially a single test of
    a global variable and jump. Hardly a big performance issue, no?

    -Andi
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  • Next message: Daniel Phillips: "Re: [RFC][PATCH 1 of 4] Configfs is really sysfs"