Re: SLRUs in the main buffer pool - Page Header definitions

2022年9月28日(水) 10:57 Bagga, Rishu <bagrishu@amazon.com>:
>
> Hi,
>
> We have been working on adding page headers to the SLRU pages, as part of the migration for SLRU to buffer cache.
We’veincorporated Thomas Munro’s patch and Heikki’s Storage manager changes[1] and have a patch for early feedback. 
>
> As part of our changes we have:
>
> 1. Added page headers to the following
>
>                *Commit_TS
>         *CLOG
>         *MultiXact
>         *Subtrans
>         *Serial (predicate.c)
>         *Notify (async.c)
>
> For commit_ts, clog and MultiXact, the PageXLogRecPtr field is populated with the LSN returned during the creation of
anew page; as there is no WAL record for the rest, PageXLogRecPtr is set to “InvalidXlogRecPtr”. 
>
> There is one failing assert in predicate.c for SerialPagePrecedes with the page header changes; we are looking into
thisissue. 
>
> The page_version is set to PG_METAPAGE_LAYOUT_VERSION (which is 1)
>
>
> 2. Change block number passed into ReadSlruBuffer from relative to absolute, and account for SLRU’s 256kb segment
sizein md.c. 
>
>
>
> The changes pass the regression tests. We are still working on handling the upgrade scenario and should have a patch
outfor that soon. 
>
> Attached is the patch with all changes (Heikki and Munro’s patch and page headers) consolidated

Hi

cfbot reports the patch no longer applies.  As CommitFest 2022-11 is
currently underway, this would be an excellent time to update the patch.

Thanks

Ian Barwick