Messages in this thread | | | Date | Thu, 06 Sep 2012 12:18:31 +0530 | From | "Naveen N. Rao" <> | Subject | Re: [PATCH 2/3] x86/mce: Pack boolean MCE flags into a structure |
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On 09/06/2012 12:26 AM, Tony Luck wrote: > On Wed, Sep 5, 2012 at 3:22 AM, Naveen N. Rao > <naveen.n.rao@linux.vnet.ibm.com> wrote: >> Many MCE flags are boolean in nature, but are declared as integers >> currently. We can pack these into a bitfield to save some space. > > Before this patch: > size arch/x86/kernel/cpu/mcheck/mce.o > text data bss dec hex filename > 18946 4930 776 24652 604c arch/x86/kernel/cpu/mcheck/mce.o > > After: > size arch/x86/kernel/cpu/mcheck/mce.o > text data bss dec hex filename > 19335 4890 776 25001 61a9 arch/x86/kernel/cpu/mcheck/mce.o > > So we do indeed see "data" reduced by 40 bytes. But > "text" is up by 389. This seems to be because you have > another change, not described in the commit log, buried > in part 2 to add get_dont_log_ce(), set_dont_log_ce() etc. > > Compiler version: gcc version 4.4.6 20120305 (Red Hat 4.4.6-4) (GCC) > > I know I'm contradicting the feedback you got from Borislav here, but > is this code churn really worth it to save 40 bytes? I don't think so.
Hmm.. I think I agree. I don't see a good way to get rid of the individual getters and setters without adding some more code churn. I guess using boolean would be better. Boris?
Thanks, Naveen
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