Feedback-ID: i0fe9450f:Fastmail
Date: Fri, 1 Nov 2024 16:36:45 +0900
From: Michael Paquier <michael@paquier.xyz>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>,
	Peter Smith <smithpb2250@gmail.com>,
	Peter Eisentraut <peter@eisentraut.org>,
	Heikki Linnakangas <hlinnaka@iki.fi>,
	pgsql-hackers@lists.postgresql.org
Subject: Re: define pg_structiszero(addr, s, r)
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On Fri, Nov 01, 2024 at 08:21:50PM +1300, David Rowley wrote:
> My vote is to just revert this usage of the function. Anything more
> elaborate would need to check pointer alignment before using any types
> larger than char. The previous code does not need to do that because
> the page is going to be at least MAXALIGNed.

Fine, here you go.  The attached reverts back this part in bufpage.c
to what it was in 49d6c7d8daba.
--
Michael

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diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/=
bufpage.c
index 5ee1e58cd4..be6f1f62d2 100644
--- a/src/backend/storage/page/bufpage.c
+++ b/src/backend/storage/page/bufpage.c
@@ -89,8 +89,10 @@ PageIsVerifiedExtended(Page page, BlockNumber blkno, int=
 flags)
 {
 	PageHeader	p =3D (PageHeader) page;
 	size_t	   *pagebytes;
+	int			i;
 	bool		checksum_failure =3D false;
 	bool		header_sane =3D false;
+	bool		all_zeroes =3D false;
 	uint16		checksum =3D 0;
=20
 	/*
@@ -124,9 +126,18 @@ PageIsVerifiedExtended(Page page, BlockNumber blkno, i=
nt flags)
 	}
=20
 	/* Check all-zeroes case */
+	all_zeroes =3D true;
 	pagebytes =3D (size_t *) page;
+	for (i =3D 0; i < (BLCKSZ / sizeof(size_t)); i++)
+	{
+		if (pagebytes[i] !=3D 0)
+		{
+			all_zeroes =3D false;
+			break;
+		}
+	}
=20
-	if (pg_memory_is_all_zeros(pagebytes, (BLCKSZ / sizeof(size_t))))
+	if (all_zeroes)
 		return true;
=20
 	/*

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