Messages in this thread | | | Date | Thu, 20 Nov 2008 21:47:17 -0800 | From | Arjan van de Ven <> | Subject | Re: A question sort_main_extable() |
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On Fri, 21 Nov 2008 13:42:56 +0800 "Peter Teoh" <htmldeveloper@gmail.com> wrote:
> Inside start_kernel() there is a call to sort_main_extable(). > > void sort_extable(struct exception_table_entry *start, > struct exception_table_entry *finish) > { > sort(start, finish - start, sizeof(struct > exception_table_entry), cmp_ex, NULL); > } > > With reference to > http://tuxology.net/2008/07/08/benchmarking-boot-latency-on-x86/, I > think it can help bootup latency (how much I got no number) if the > sorting is done post-compilation time, instead of dynamically > everytime the system bootup. (perhaps at the stage of modposting, > when all the vmlinux, kernel modules objects have been generated, so > extracting out the exceptions strings is possible?) Is this a > possible optimization?
we used to do this but it was a pain and extremely fragile. Runtime sorting makes it very robust at least.
The sort is really quick though; I've spent a lot of time on boot time and this guy never showed up for me.
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
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