Re: objrmap-core-1 (rmap removal for file mappings to avoid 4:4 in <=16G machines)

Andrea Arcangeli
2004-03-09T16:33:07Z

On Tue, Mar 09, 2004 at 04:36:20PM +0100, Ingo Molnar wrote:
>
> * Andrea Arcangeli <andrea@suse.de> wrote:
>
> > http://www.oracle.com/apps_benchmark/html/index.html?0325B_Report1.html
>
> OASB is special and pushes the DB less than e.g. TPC-C does. How big was
> the SGA? I bet the setup didnt have use_indirect_data_buffers=true.

I don't know the answer of this, but it was the usual top configuration
with very large memory model, I'm not aware of a superior config on x86
and this triggered bugs for the first time ever which could mean we were
the first ever pushing the db that far.

> (OASB is not a full-disclosure benchmark so i have no way to check
> this.) All you have proven is that workloads with a limited number of
> per-inode vmas can perform well. Which completely ignores my point.

what is your point, that OASB is a worthless workload and the only thing
that matters is TPC-C? Maybe you should discuss your point with Oracle
not with me, since I don't know what the two benchmarks are doing
differently. TCP-C was tested too of course, but maybe not in 32G boxes,
frankly I thought OASB was harder than TCP-C, as I think Martin
mentioned too two days ago.

about the limited number of vmas per inode, that's not the case, there
were tons of vmas allocated at least a 512m SGA window per 7.5k tasks,
infact without the vma-file-merging there's no way to make that work.
But the number of vmas isn't relevant with 2.6 and remap_file_pages, so
whatever your point is, I don't see it.