diff options
| author | David Rowley <drowley@postgresql.org> | 2024-04-07 23:32:00 +1200 |
|---|---|---|
| committer | David Rowley <drowley@postgresql.org> | 2024-04-07 23:32:00 +1200 |
| commit | 0ba8b75e7ea6b7b3090c81239ebcb866772a624b (patch) | |
| tree | 3015678f6979d3f4fff6dedf80fb0ff938ee273c /src/include/utils/memutils_internal.h | |
| parent | c4ab7da60617f020e8d75b1584d0754005d71830 (diff) | |
| download | postgresql-0ba8b75e7ea6b7b3090c81239ebcb866772a624b.tar.gz postgresql-0ba8b75e7ea6b7b3090c81239ebcb866772a624b.zip | |
Enlarge bit-space for MemoryContextMethodID
Reserve 4 bits for MemoryContextMethodID rather than 3. 3 bits did
technically allow a maximum of 8 memory context types, however, we've
opted to reserve some bit patterns which left us with only 4 slots, all
of which were used.
Here we add another bit which frees up 8 slots for future memory context
types.
In passing, adjust the enum names in MemoryContextMethodID to make it
more clear which ones can be used and which ones are reserved.
Author: Matthias van de Meent, David Rowley
Discussion: https://postgr.es/m/CAApHDvqGSpCU95TmM=Bp=6xjL_nLys4zdZOpfNyWBk97Xrdj2w@mail.gmail.com
Diffstat (limited to 'src/include/utils/memutils_internal.h')
| -rw-r--r-- | src/include/utils/memutils_internal.h | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/src/include/utils/memutils_internal.h b/src/include/utils/memutils_internal.h index ad1048fd829..2d032611556 100644 --- a/src/include/utils/memutils_internal.h +++ b/src/include/utils/memutils_internal.h @@ -104,21 +104,29 @@ extern Size AlignedAllocGetChunkSpace(void *pointer); */ typedef enum MemoryContextMethodID { - MCTX_UNUSED1_ID, /* 000 occurs in never-used memory */ - MCTX_UNUSED2_ID, /* glibc malloc'd chunks usually match 001 */ - MCTX_UNUSED3_ID, /* glibc malloc'd chunks > 128kB match 010 */ + MCTX_0_RESERVED_UNUSEDMEM_ID, /* 0000 occurs in never-used memory */ + MCTX_1_RESERVED_GLIBC_ID, /* glibc malloc'd chunks usually match 0001 */ + MCTX_2_RESERVED_GLIBC_ID, /* glibc malloc'd chunks > 128kB match 0010 */ MCTX_ASET_ID, MCTX_GENERATION_ID, MCTX_SLAB_ID, MCTX_ALIGNED_REDIRECT_ID, - MCTX_UNUSED4_ID, /* 111 occurs in wipe_mem'd memory */ + MCTX_7_UNUSED_ID, + MCTX_8_UNUSED_ID, + MCTX_9_UNUSED_ID, + MCTX_10_UNUSED_ID, + MCTX_11_UNUSED_ID, + MCTX_12_UNUSED_ID, + MCTX_13_UNUSED_ID, + MCTX_14_UNUSED_ID, + MCTX_15_RESERVED_WIPEDMEM_ID /* 1111 occurs in wipe_mem'd memory */ } MemoryContextMethodID; /* * The number of bits that 8-byte memory chunk headers can use to encode the * MemoryContextMethodID. */ -#define MEMORY_CONTEXT_METHODID_BITS 3 +#define MEMORY_CONTEXT_METHODID_BITS 4 #define MEMORY_CONTEXT_METHODID_MASK \ ((((uint64) 1) << MEMORY_CONTEXT_METHODID_BITS) - 1) |