From 0619925d04488f9b04b72eeaa7dea64eeda5e37f Mon Sep 17 00:00:00 2001 From: Jakub Wartak Date: Fri, 31 Jul 2026 13:51:03 +0200 Subject: [PATCH v06082026 05/10] basebackup: issue posix_fadvise() for more efficient cold-cache handling By informing the OS that we are going need whole file being backed up quite soon, it can perform more efficient read-ahead. This in turns allows our synchronous basebackup_read_file()->pread64() calls to get lower latencies (as they fetch faster just from page-cache more often) and therefore this increases the efficiency of the whole data transfer. Author: Jakub Wartak --- src/backend/backup/basebackup.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c index d609355f429..dedfde74f90 100644 --- a/src/backend/backup/basebackup.c +++ b/src/backend/backup/basebackup.c @@ -1600,6 +1600,14 @@ sendFile(bbsink *sink, const char *readfilename, const char *tarfilename, errmsg("could not open file \"%s\": %m", readfilename))); } + /* + * Let the OS know that we are going to read the whole file. It's just an + * hint, but it helps avoid longer synchronous read stalls. + */ +#if defined(USE_POSIX_FADVISE) && defined(POSIX_FADV_SEQUENTIAL) + (void) posix_fadvise(fd, 0, 0, POSIX_FADV_SEQUENTIAL); +#endif + _tarWriteHeader(sink, tarfilename, NULL, statbuf, false); /* -- 2.43.0