pg_buffercache: Remove unused fields from BufferCacheNumaRec

These fields have been added in commit ba2a3c2302f, and have never been
used.  While on it, this commit moves a comment that was out of place,
improving it.

Author: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/aSBOKX6pLJzumbmF@ip-10-97-1-34.eu-west-3.compute.internal

diff --git a/contrib/pg_buffercache/pg_buffercache_pages.c b/contrib/pg_buffercache/pg_buffercache_pages.c
index c29b784dfa1accc7fcda7c004623d87dd9d4b849..7c9ff24fa837cd99a4809a4fdcde41d8620b314c 100644 (file)
--- a/contrib/pg_buffercache/pg_buffercache_pages.c
+++ b/contrib/pg_buffercache/pg_buffercache_pages.c
@@ -82,9 +82,6 @@ typedef struct
 typedef struct
 {
    TupleDesc   tupdesc;
-   int         buffers_per_page;
-   int         pages_per_buffer;
-   int         os_page_size;
    BufferCacheNumaRec *record;
 } BufferCacheNumaContext;
 
@@ -368,7 +365,12 @@ pg_buffercache_numa_pages(PG_FUNCTION_ARGS)
        os_page_ptrs = palloc0(sizeof(void *) * os_page_count);
        os_page_status = palloc(sizeof(uint64) * os_page_count);
 
-       /* Fill pointers for all the memory pages. */
+       /*
+        * Fill pointers for all the memory pages.  This loop stores and
+        * touches (if needed) addresses into os_page_ptrs[] as input to one
+        * big move_pages(2) inquiry system call, as done in
+        * pg_numa_query_pages().
+        */
        idx = 0;
        for (char *ptr = startptr; ptr < endptr; ptr += os_page_size)
        {
@@ -449,10 +451,6 @@ pg_buffercache_numa_pages(PG_FUNCTION_ARGS)
         * We don't hold the partition locks, so we don't get a consistent
         * snapshot across all buffers, but we do grab the buffer header
         * locks, so the information of each buffer is self-consistent.
-        *
-        * This loop touches and stores addresses into os_page_ptrs[] as input
-        * to one big move_pages(2) inquiry system call. Basically we ask for
-        * all memory pages for NBuffers.
         */
        startptr = (char *) TYPEALIGN_DOWN(os_page_size, (char *) BufferGetBlock(1));
        idx = 0;