Re: [PATCHES] WAL: O_DIRECT and multipage-writer (+

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Re: [PATCHES] WAL: O_DIRECT and multipage-writer (+

Bruce Momjian-2

Yes, I assume that the patch to group the writes isn't something we want
right now, and the one for O_DIRECT is going to need an additional
fsync, and I have asked for testing on that.

I have posted a patch that I think fixes the memory leak reported and am
waiting for feedback on that.

---------------------------------------------------------------------------

Simon Riggs wrote:

> On Tue, 2005-03-01 at 13:53 -0800, Mark Wong wrote:
> > On Thu, Feb 03, 2005 at 07:25:55PM +0900, ITAGAKI Takahiro wrote:
> > > Hello everyone.
> > >
> > > I fixed two bugs in the patch that I sent before.
> > > Check and test new one, please.
> >
> > Ok, finally got back into the office and was able to run 1 set of
> > tests.
> >
> > So the new baseline result with 8.0.1:
> >         http://www.osdl.org/projects/dbt2dev/results/dev4-010/309/
> >         Throughput: 3639.97
> >
> > Results with the patch but open_direct not set:
> >         http://www.osdl.org/projects/dbt2dev/results/dev4-010/308/
> >         Throughput: 3494.72
> >
> > Results with the patch and open_direct set:
> >         http://www.osdl.org/projects/dbt2dev/results/dev4-010/312/
> >         Throughput: 3489.69
> >
> > You can verify that the wall_sync_method is set to open_direct under
> > the "database parameters" link, but I'm wondering if I missed
> > something.  It looks a little odd the the performance dropped.
>
> Is there anything more to say on this?
> Is it case-closed, or is there further work underway - I can't see any
> further chat on this thread.
>
> These results show it doesn't work better on larger systems. The
> original testing showed it worked better on smaller systems - is there
> still scope to include this for smaller configs?
>
> If not, thanks for taking the time to write the patch and investigate
> whether changes in this area would help. Not every performance patch
> improves things, but that doesn't mean we shouldn't try...
>
> Best Regards, Simon Riggs
>
>
>
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--
  Bruce Momjian                        |  http://candle.pha.pa.us
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