Re: Scaling XLog insertion (was Re: Moving more work outside WALInsertLock)

On Wed, Mar 21, 2012 at 10:59 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
>> ... although none of the issues alone is a show-stopper, but considering
>> all these things together, I'm starting to feel that this needs to be
>> pushed to 9.3. Thoughts?
>
> Agreed.  In particular, I think you are right that it'd be prudent to
> simplify the WAL-location arithmetic and then rebase this code onto
> that.  And since no code at all has been written for the arithmetic
> change, I think we have to consider that it's not 9.2 material.

Agreed.

BTW, the patch changes some functions so that they use volatile pointer,
as follows:

@@ -8448,7 +9232,7 @@ XLogReportParameters(void)
void
UpdateFullPageWrites(void)
{
- XLogCtlInsert *Insert = &XLogCtl->Insert;
+ volatile XLogCtlInsert *Insert = &XLogCtl->Insert;

These changes should be applied?

Regards,

--
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center