Re: [Bugme-new] [Bug 15618] New: 2.6.18->2.6.32->2.6.33 hugeregression in performance

From: Robin Holt
Date: Tue Mar 23 2010 - 15:57:41 EST


On Tue, Mar 23, 2010 at 02:49:59PM -0500, Robin Holt wrote:
> On Tue, Mar 23, 2010 at 08:30:19PM +0100, Anton Starikov wrote:
> >
> > On Mar 23, 2010, at 8:22 PM, Robin Holt wrote:
> >
> > > On Tue, Mar 23, 2010 at 07:25:43PM +0100, Anton Starikov wrote:
> > >> On Mar 23, 2010, at 7:21 PM, Andrew Morton wrote:
> > >>>> I will apply this commits to 2.6.32, I afraid current OFED (which I need also) will not work on 2.6.33+.
> > >>>>
> > >>>
> > >>> You should be able to simply set CONFIG_RWSEM_GENERIC_SPINLOCK=n,
> > >>> CONFIG_RWSEM_XCHGADD_ALGORITHM=y by hand, as I mentioned earlier?
> > >>
> > >> Hm. I tried, but when I do "make oldconfig", then it gets rewritten, so I assume that it conflicts with some other setting from default fedora kernel config. trying to figure out which one exactly.
> > >
> > > Have you tracked this down yet? I just got the patches applied against
> > > an older kernel and am running into the same issue.
> >
> > I decided to not track down this issue and just applied patches. I understood that with this patches there is no need to change this config options. Am I wrong?
>
> We might need to also apply:
> bafaecd11df15ad5b1e598adc7736afcd38ee13d

For the record, these are the patches I have applied to a 2.6.32 kernel from a vendor:

59c33fa7791e9948ba467c2b83e307a0d087ab49
5d0b7235d83eefdafda300656e97d368afcafc9a
1838ef1d782f7527e6defe87e180598622d2d071
0d1622d7f526311d87d7da2ee7dd14b73e45d3fc
bafaecd11df15ad5b1e598adc7736afcd38ee13d

A quick look at the disassembly makes it look like we are using the
rwsem_64, et al.

Robin
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