Search for SLRU page only in its own bank

One of the two slot scans in SlruSelectLRUPage was not walking only the
slots in the specific bank where the buffer could be; change it to do
that.

Oversight in 53c2a97a9266.

Author: Sergey Sargsyan <[email protected]>
Discussion: https://postgr.es/m/18582-5f301dd30ba91a38@postgresql.org

diff --git a/src/backend/access/transam/slru.c b/src/backend/access/transam/slru.c
index 248aa1a6553b6106013b4f4391e65a9914900d5b..27473009b002867e8cd0000f6e5b61143ee97b6f 100644 (file)
--- a/src/backend/access/transam/slru.c
+++ b/src/backend/access/transam/slru.c
@@ -1184,7 +1184,7 @@ SlruSelectLRUPage(SlruCtl ctl, int64 pageno)
        Assert(LWLockHeldByMe(SimpleLruGetBankLock(ctl, pageno)));
 
        /* See if page already has a buffer assigned */
-       for (int slotno = 0; slotno < shared->num_slots; slotno++)
+       for (int slotno = bankstart; slotno < bankend; slotno++)
        {
            if (shared->page_status[slotno] != SLRU_PAGE_EMPTY &&
                shared->page_number[slotno] == pageno)