From 4d46a93398ae4da3b73d9377234bafb5c7ae45eb Mon Sep 17 00:00:00 2001 From: Jakub Wartak Date: Fri, 31 Jul 2026 10:13:57 +0200 Subject: [PATCH v06102026 04/10] basebackup: bump SINK_BUFFER_LENGTH to 256kB By increasing SINK_BUFFER_LENGTH size to be closer to modern L2 CPU cache sizes, we are also reducing frequency of the pread() system call which also helps avoids performance penalties (and is visible as one of the top functions when sending backups). In isolated performance runs where pg_basebackup client did not have write it's backup to disk, this gives ~180% of the baseline (3.1GB/s -> 5.5GB/s). Author: Jakub Wartak Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/CAKZiRmwwW-hDc3B6ERJB%2BpaX7RNSBcQLheq1KdsTf42cGuRvuA%40mail.gmail.com --- src/backend/backup/basebackup.c | 2 +- src/backend/backup/basebackup_progress.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/backend/backup/basebackup.c b/src/backend/backup/basebackup.c index e3c04ecd810..6478218cc91 100644 --- a/src/backend/backup/basebackup.c +++ b/src/backend/backup/basebackup.c @@ -59,7 +59,7 @@ * NB: The buffer size is required to be a multiple of the system block * size, so use that value instead if it's bigger than our preference. */ -#define SINK_BUFFER_LENGTH Max(32768, BLCKSZ) +#define SINK_BUFFER_LENGTH Max(256 * 1024, BLCKSZ) typedef struct { diff --git a/src/backend/backup/basebackup_progress.c b/src/backend/backup/basebackup_progress.c index f74459181d0..1d8b24dfdc9 100644 --- a/src/backend/backup/basebackup_progress.c +++ b/src/backend/backup/basebackup_progress.c @@ -63,7 +63,7 @@ bbsink_progress_new(bbsink *next, bool estimate_backup_size, bool incremental) Assert(next != NULL); - sink = palloc0_object(bbsink); + sink = palloc_aligned(sizeof(bbsink), PG_IO_ALIGN_SIZE, MCXT_ALLOC_ZERO); *((const bbsink_ops **) &sink->bbs_ops) = &bbsink_progress_ops; sink->bbs_next = next; -- 2.43.0