Re: [LKP] [ftrace] fef5aeeee9e: -27.2% boot-slabinfo.num_objs

From: Huang Ying
Date: Sun Dec 28 2014 - 21:28:30 EST


On Tue, 2014-12-23 at 08:32 -0500, Steven Rostedt wrote:
> On Tue, 23 Dec 2014 11:10:17 +0800
> Huang Ying <ying.huang@xxxxxxxxx> wrote:
>
> > FYI, we noticed the below changes on
> >
> > commit fef5aeeee9e3717e7aea991a7ae9ff6a7a2d4c85 ("ftrace: Replace tramp_hash with old_*_hash to save space")
> >
> >
> > testbox/testcase/testparams: vm-kbuild-4G/boot/1
> >
> > e1effa0144a1ddf5 fef5aeeee9e3717e7aea991a7a
> > ---------------- --------------------------
> > %stddev %change %stddev
> > \ | \
> > 437752 Â 0% -27.2% 318545 Â 0% boot-slabinfo.num_objs
> >
> > vm-kbuild-4G: qemu-system-x86_64 -enable-kvm
> > Memory: 4G
>
> I have no idea what this test does. Is this good or bad? Is that -27.2%
> a performance regression, or memory regression?

IMO, it is good. Memory usage is reduced.

Best Regards,
Huang, Ying

> -- Steve
>
>
> >
> >
> >
> > boot-slabinfo.num_objs
> >
> > 440000 *+*--*-*-*------*----*-*-*--*--------*-*--*-*-*--*-----------------+
> > | *.* *. *.*..* |
> > 420000 ++ |
> > | |
> > 400000 ++ |
> > | |
> > 380000 ++ |
> > | |
> > 360000 ++ |
> > | |
> > 340000 ++ |
> > | |
> > 320000 O+O O O O O O O O O O O O O O O O O O O O O O O O O O
> > | O O O |
> > 300000 ++-----------------------------------------------------------------+
> >
> > [*] bisect-good sample
> > [O] bisect-bad sample
> >
> > To reproduce:
> >
> > apt-get install ruby ruby-oj
> > git clone git://git.kernel.org/pub/scm/linux/kernel/git/wfg/lkp-tests.git
> > cd lkp-tests
> > bin/setup-local job.yaml # the job file attached in this email
> > bin/run-local job.yaml
> >
> >
> > Disclaimer:
> > Results have been estimated based on internal Intel analysis and are provided
> > for informational purposes only. Any difference in system hardware or software
> > design or configuration may affect actual performance.
> >
> >
> > Thanks,
> > Huang, Ying
> >
>


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