Add support for sharded bins within an arena.

This makes it possible to have multiple set of bins in an arena, which improves
arena scalability because the bins (especially the small ones) are always the
limiting factor in production workload.

A bin shard is picked on allocation; each extent tracks the bin shard id for
deallocation.  The shard size will be determined using runtime options.
This commit is contained in:
Qi Wang
2018-11-12 15:56:04 -08:00
committed by Qi Wang
parent b23336af96
commit 37b8913925
12 changed files with 217 additions and 73 deletions

View File

@@ -29,9 +29,10 @@ struct extent_s {
* t: state
* i: szind
* f: nfree
* s: bin_shard
* n: sn
*
* nnnnnnnn ... nnnnffff ffffffii iiiiiitt zdcbaaaa aaaaaaaa
* nnnnnnnn ... nnnnnnss ssssffff ffffffii iiiiiitt zdcbaaaa aaaaaaaa
*
* arena_ind: Arena from which this extent came, or all 1 bits if
* unassociated.
@@ -76,6 +77,8 @@ struct extent_s {
*
* nfree: Number of free regions in slab.
*
* bin_shard: the shard of the bin from which this extent came.
*
* sn: Serial number (potentially non-unique).
*
* Serial numbers may wrap around if !opt_retain, but as long as
@@ -121,7 +124,15 @@ struct extent_s {
#define EXTENT_BITS_NFREE_SHIFT (EXTENT_BITS_SZIND_WIDTH + EXTENT_BITS_SZIND_SHIFT)
#define EXTENT_BITS_NFREE_MASK MASK(EXTENT_BITS_NFREE_WIDTH, EXTENT_BITS_NFREE_SHIFT)
#define EXTENT_BITS_SN_SHIFT (EXTENT_BITS_NFREE_WIDTH + EXTENT_BITS_NFREE_SHIFT)
#define EXTENT_BITS_BINSHARD_WIDTH 6
#define EXTENT_BITS_BINSHARD_SHIFT (EXTENT_BITS_NFREE_WIDTH + EXTENT_BITS_NFREE_SHIFT)
#define EXTENT_BITS_BINSHARD_MASK MASK(EXTENT_BITS_BINSHARD_WIDTH, EXTENT_BITS_BINSHARD_SHIFT)
/* Will make dynamic options. */
#define OPT_N_BIN_SHARDS (1)
#define OPT_BIN_SHARD_MAXSZIND (0)
#define EXTENT_BITS_SN_SHIFT (EXTENT_BITS_BINSHARD_WIDTH + EXTENT_BITS_BINSHARD_SHIFT)
#define EXTENT_BITS_SN_MASK (UINT64_MAX << EXTENT_BITS_SN_SHIFT)
/* Pointer to the extent that this structure is responsible for. */