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

2022年9月28日(水) 10:57 Bagga, Rishu <bagrishu(at)amazon(dot)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’ve incorporated 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 a new 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 this issue.
>
> 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 size in md.c.
>
>
>
> The changes pass the regression tests. We are still working on handling the upgrade scenario and should have a patch out for 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