From 02fbbbf691ab28f267f5426bb4f3ba7c8cd950dc Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 26 Jan 2025 14:13:57 -0500 Subject: [PATCH v1 2/3] bufmgr: Assert that MAX_BACKENDS is compatible with BufferDesc.state Author: Reviewed-by: Discussion: https://postgr.es/m/ Backpatch: --- src/include/storage/buf_internals.h | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h index 1a65342177d..d93493f746b 100644 --- a/src/include/storage/buf_internals.h +++ b/src/include/storage/buf_internals.h @@ -39,8 +39,9 @@ * * The definition of buffer state components is below. */ +#define BUF_REFCOUNT_BITS 18 #define BUF_REFCOUNT_ONE 1 -#define BUF_REFCOUNT_MASK ((1U << 18) - 1) +#define BUF_REFCOUNT_MASK ((1U << BUF_REFCOUNT_BITS) - 1) #define BUF_USAGECOUNT_MASK 0x003C0000U #define BUF_USAGECOUNT_ONE (1U << 18) #define BUF_USAGECOUNT_SHIFT 18 @@ -77,6 +78,9 @@ */ #define BM_MAX_USAGE_COUNT 5 +StaticAssertDecl(MAX_BACKENDS <= ((1 << BUF_REFCOUNT_BITS) - 1), + "MAX_BACKENDS is too big for BUF_REFCOUNT_BITS"); + /* * Buffer tag identifies which disk block the buffer contains. * -- 2.48.1.76.g4e746b1a31.dirty