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Re: pgsql: Introduce pg_shmem_allocations_numa view - Mailing list pgsql-hackers

From	Christoph Berg
Subject	Re: pgsql: Introduce pg_shmem_allocations_numa view
Date	June 23 23:51:49
Msg-id	aFm-ZfL-vz9I2Zmc@msg.df7cb.de Whole thread Raw
In response to	Re: pgsql: Introduce pg_shmem_allocations_numa view (Christoph Berg <myon@debian.org>)
List	pgsql-hackers
Tree view
Re: Tomas Vondra
> Didn't you say the first ~35 addresses succeed, right? What about the
> addresses after that?

That was pg_shmem_allocations_numa. The pg_numa_query_pages() in there
works (does not return -1), but then some of the status[] values are
-14.

When pg_buffercache_numa fails, pg_numa_query_pages() itself
returns -14.

The printed os_page_ptrs[] contents are the same for the failing and
non-failing calls, so the problem is probably elsewhere.

        /* Fill pointers for all the memory pages. */
        idx = 0;
        for (char *ptr = startptr; ptr < endptr; ptr += os_page_size)
        {
+           if (idx < 50)
+               elog(DEBUG1, "os_page_ptrs idx %d = %p", idx, ptr);
            os_page_ptrs[idx++] = ptr;


20:47 myon@postgres =# select * from pg_buffercache_numa;
DEBUG:  00000: os_page_ptrs idx 0 = 0xebc44000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 1 = 0xebc45000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 2 = 0xebc46000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 3 = 0xebc47000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 4 = 0xebc48000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 5 = 0xebc49000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 6 = 0xebc4a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 7 = 0xebc4b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 8 = 0xebc4c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 9 = 0xebc4d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 10 = 0xebc4e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 11 = 0xebc4f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 12 = 0xebc50000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 13 = 0xebc51000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 14 = 0xebc52000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 15 = 0xebc53000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 16 = 0xebc54000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 17 = 0xebc55000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 18 = 0xebc56000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 19 = 0xebc57000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 20 = 0xebc58000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 21 = 0xebc59000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 22 = 0xebc5a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 23 = 0xebc5b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 24 = 0xebc5c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 25 = 0xebc5d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 26 = 0xebc5e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 27 = 0xebc5f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 28 = 0xebc60000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 29 = 0xebc61000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 30 = 0xebc62000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 31 = 0xebc63000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 32 = 0xebc64000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 33 = 0xebc65000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 34 = 0xebc66000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 35 = 0xebc67000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 36 = 0xebc68000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 37 = 0xebc69000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 38 = 0xebc6a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 39 = 0xebc6b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 40 = 0xebc6c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 41 = 0xebc6d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 42 = 0xebc6e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 43 = 0xebc6f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 44 = 0xebc70000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 45 = 0xebc71000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 46 = 0xebc72000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 47 = 0xebc73000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 48 = 0xebc74000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 49 = 0xebc75000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: NUMA: NBuffers=16384 os_page_count=32768 os_page_size=4096
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:385
2025-06-23 20:47:41.827 UTC [1368080] ERROR:  failed NUMA pages inquiry: Bad address
2025-06-23 20:47:41.827 UTC [1368080] STATEMENT:  select * from pg_buffercache_numa;
ERROR:  XX000: failed NUMA pages inquiry: Bad address
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:396
Time: 92.757 ms

20:47 myon@postgres =# select * from pg_buffercache_numa;
DEBUG:  00000: os_page_ptrs idx 0 = 0xebc44000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 1 = 0xebc45000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 2 = 0xebc46000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 3 = 0xebc47000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 4 = 0xebc48000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 5 = 0xebc49000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 6 = 0xebc4a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 7 = 0xebc4b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 8 = 0xebc4c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 9 = 0xebc4d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 10 = 0xebc4e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 11 = 0xebc4f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 12 = 0xebc50000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 13 = 0xebc51000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 14 = 0xebc52000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 15 = 0xebc53000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 16 = 0xebc54000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 17 = 0xebc55000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 18 = 0xebc56000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 19 = 0xebc57000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 20 = 0xebc58000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 21 = 0xebc59000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 22 = 0xebc5a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 23 = 0xebc5b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 24 = 0xebc5c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 25 = 0xebc5d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 26 = 0xebc5e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 27 = 0xebc5f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 28 = 0xebc60000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 29 = 0xebc61000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 30 = 0xebc62000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 31 = 0xebc63000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 32 = 0xebc64000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 33 = 0xebc65000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 34 = 0xebc66000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 35 = 0xebc67000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 36 = 0xebc68000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 37 = 0xebc69000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 38 = 0xebc6a000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 39 = 0xebc6b000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 40 = 0xebc6c000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 41 = 0xebc6d000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 42 = 0xebc6e000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 43 = 0xebc6f000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 44 = 0xebc70000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 45 = 0xebc71000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 46 = 0xebc72000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 47 = 0xebc73000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 48 = 0xebc74000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: os_page_ptrs idx 49 = 0xebc75000
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:375
DEBUG:  00000: NUMA: NBuffers=16384 os_page_count=32768 os_page_size=4096
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:385
DEBUG:  00000: NUMA: page-faulting the buffercache for proper NUMA readouts
LOCATION:  pg_buffercache_numa_pages, pg_buffercache_pages.c:444
Time: 24.547 ms
20:47 myon@postgres =#


Christoph
pgsql-hackers by date:
From: Melanie Plageman
Date: 23 June, 23:25:16
Subject: eliminate xl_heap_visible to reduce WAL (and eventually set VM on-access)
From: Noah Misch
Date: 24 June, 02:16:09
Subject: Re: Proper object locking for GRANT/REVOKE
Re: pgsql: Introduce pg_shmem_allocations_numa view - Mailing list pgsql-hackers

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