From 3e0ae46d907dd5f36342dd288841f4502bd571f6 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 10 Nov 2025 16:11:41 +0200 Subject: Move SLRU_PAGES_PER_SEGMENT to pg_config_manual.h MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It seems plausible that someone might want to experiment with different values. The pressing reason though is that I'm reviewing a patch that requires pg_upgrade to manipulate SLRU files. That patch needs to access SLRU_PAGES_PER_SEGMENT from pg_upgrade code, and slru.h, where SLRU_PAGES_PER_SEGMENT is currently defined, cannot be included from frontend code. Moving it to pg_config_manual.h makes it accessible. Now that it's a little more likely that someone might change SLRU_PAGES_PER_SEGMENT, add a cluster compatibility check for it. Bump catalog version because of the new field in the control file. Reviewed-by: Daniel Gustafsson Reviewed-by: Álvaro Herrera Discussion: https://www.postgresql.org/message-id/c7a4ea90-9f7b-4953-81be-b3fcb47db057@iki.fi --- src/backend/access/transam/xlog.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'src/backend/access/transam/xlog.c') diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 101b616b028..22d0a2e8c3a 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -4271,6 +4271,7 @@ WriteControlFile(void) ControlFile->blcksz = BLCKSZ; ControlFile->relseg_size = RELSEG_SIZE; + ControlFile->slru_pages_per_segment = SLRU_PAGES_PER_SEGMENT; ControlFile->xlog_blcksz = XLOG_BLCKSZ; ControlFile->xlog_seg_size = wal_segment_size; @@ -4490,6 +4491,16 @@ ReadControlFile(void) "RELSEG_SIZE", ControlFile->relseg_size, "RELSEG_SIZE", RELSEG_SIZE), errhint("It looks like you need to recompile or initdb."))); + if (ControlFile->slru_pages_per_segment != SLRU_PAGES_PER_SEGMENT) + ereport(FATAL, + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), + errmsg("database files are incompatible with server"), + /* translator: %s is a variable name and %d is its value */ + errdetail("The database cluster was initialized with %s %d," + " but the server was compiled with %s %d.", + "SLRU_PAGES_PER_SEGMENT", ControlFile->slru_pages_per_segment, + "SLRU_PAGES_PER_SEGMENT", SLRU_PAGES_PER_SEGMENT), + errhint("It looks like you need to recompile or initdb."))); if (ControlFile->xlog_blcksz != XLOG_BLCKSZ) ereport(FATAL, (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE), -- cgit v1.2.3