Re-add tracking of wait event SLRUFlushSync

SLRUFlushSync has been accidently removed during dee663f, that has moved
the flush of the SLRU files to the checkpointer, so add it back.  The
issue has been noticed by Thomas when checking for orphaned wait
events.

Author: Thomas Munro
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/CA+hUKGK6tqm59KuF1z+h5Y8fsWcu5v8+84kduSHwRzwjB2aa_A@mail.gmail.com

diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 3afd5340911606afec19c4618d25ed02668831fc..af57fe9e53ac96fdc56af5363d8859f75a84e6ba 100644 (file)
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -1603,7 +1603,9 @@ SlruSyncFileTag(SlruCtl ctl, const FileTag *ftag, char *path)
    if (fd < 0)
        return -1;
 
+   pgstat_report_wait_start(WAIT_EVENT_SLRU_FLUSH_SYNC);
    result = pg_fsync(fd);
+   pgstat_report_wait_end();
    save_errno = errno;
 
    CloseTransientFile(fd);