diff options
Diffstat (limited to 'include/jemalloc/internal/arena.h')
| -rw-r--r-- | include/jemalloc/internal/arena.h | 53 |
1 files changed, 24 insertions, 29 deletions
diff --git a/include/jemalloc/internal/arena.h b/include/jemalloc/internal/arena.h index 49213e3..561c9b6 100644 --- a/include/jemalloc/internal/arena.h +++ b/include/jemalloc/internal/arena.h @@ -38,10 +38,10 @@ * * (nactive >> opt_lg_dirty_mult) >= ndirty * - * So, supposing that opt_lg_dirty_mult is 5, there can be no less than 32 - * times as many active pages as dirty pages. + * So, supposing that opt_lg_dirty_mult is 3, there can be no less than 8 times + * as many active pages as dirty pages. */ -#define LG_DIRTY_MULT_DEFAULT 5 +#define LG_DIRTY_MULT_DEFAULT 3 typedef struct arena_chunk_map_s arena_chunk_map_t; typedef struct arena_chunk_s arena_chunk_t; @@ -69,7 +69,7 @@ struct arena_chunk_map_s { /* * Linkage for run trees. There are two disjoint uses: * - * 1) arena_t's runs_avail_{clean,dirty} trees. + * 1) arena_t's runs_avail tree. * 2) arena_run_t conceptually uses this linkage for in-use * non-full runs, rather than directly embedding linkage. */ @@ -162,20 +162,24 @@ typedef rb_tree(arena_chunk_map_t) arena_run_tree_t; /* Arena chunk header. */ struct arena_chunk_s { /* Arena that owns the chunk. */ - arena_t *arena; + arena_t *arena; - /* Linkage for the arena's chunks_dirty list. */ - ql_elm(arena_chunk_t) link_dirty; - - /* - * True if the chunk is currently in the chunks_dirty list, due to - * having at some point contained one or more dirty pages. Removal - * from chunks_dirty is lazy, so (dirtied && ndirty == 0) is possible. - */ - bool dirtied; + /* Linkage for tree of arena chunks that contain dirty runs. */ + rb_node(arena_chunk_t) dirty_link; /* Number of dirty pages. */ - size_t ndirty; + size_t ndirty; + + /* Number of available runs. */ + size_t nruns_avail; + + /* + * Number of available run adjacencies. Clean and dirty available runs + * are not coalesced, which causes virtual memory fragmentation. The + * ratio of (nruns_avail-nruns_adjac):nruns_adjac is used for tracking + * this fragmentation. + * */ + size_t nruns_adjac; /* * Map of pages within chunk that keeps track of free/large/small. The @@ -183,7 +187,7 @@ struct arena_chunk_s { * need to be tracked in the map. This omission saves a header page * for common chunk sizes (e.g. 4 MiB). */ - arena_chunk_map_t map[1]; /* Dynamically sized. */ + arena_chunk_map_t map[1]; /* Dynamically sized. */ }; typedef rb_tree(arena_chunk_t) arena_chunk_tree_t; @@ -333,8 +337,8 @@ struct arena_s { dss_prec_t dss_prec; - /* List of dirty-page-containing chunks this arena manages. */ - ql_head(arena_chunk_t) chunks_dirty; + /* Tree of dirty-page-containing chunks this arena manages. */ + arena_chunk_tree_t chunks_dirty; /* * In order to avoid rapid chunk allocation/deallocation when an arena @@ -369,18 +373,9 @@ struct arena_s { /* * Size/address-ordered trees of this arena's available runs. The trees - * are used for first-best-fit run allocation. The dirty tree contains - * runs with dirty pages (i.e. very likely to have been touched and - * therefore have associated physical pages), whereas the clean tree - * contains runs with pages that either have no associated physical - * pages, or have pages that the kernel may recycle at any time due to - * previous madvise(2) calls. The dirty tree is used in preference to - * the clean tree for allocations, because using dirty pages reduces - * the amount of dirty purging necessary to keep the active:dirty page - * ratio below the purge threshold. + * are used for first-best-fit run allocation. */ - arena_avail_tree_t runs_avail_clean; - arena_avail_tree_t runs_avail_dirty; + arena_avail_tree_t runs_avail; /* bins is used to store trees of free regions. */ arena_bin_t bins[NBINS]; |