From 4bbbf4ff9b3fe4be24bf8d57780c84d5b3ca0f77 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Mon, 27 Feb 2017 15:27:05 +0100 Subject: erts: Convert small sub-binaries to heap-binaries In many cases sub-binaries costs more memory than converting them to heap-binaries. Sub-binaries also has a hidden cost of pinning larger binaries in memory. By converting binaries this cost is reduced. Byte aligned sub-binaries upto 24 bytes (64-bit) or 12 bytes (32-bit) are converted. --- erts/emulator/beam/erl_binary.h | 18 +---------- erts/emulator/beam/erl_bits.h | 17 ++++++++++ erts/emulator/beam/erl_gc.c | 33 +++++++++++++++++++ erts/emulator/beam/erl_gc.h | 70 ++++++++++++++++++++++++++++------------- 4 files changed, 100 insertions(+), 38 deletions(-) diff --git a/erts/emulator/beam/erl_binary.h b/erts/emulator/beam/erl_binary.h index 946d3cfe03..6ff71ec6d1 100644 --- a/erts/emulator/beam/erl_binary.h +++ b/erts/emulator/beam/erl_binary.h @@ -156,6 +156,7 @@ typedef union { #include "erl_threads.h" #include "bif.h" #include "erl_bif_unique.h" +#include "erl_bits.h" /* * Maximum number of bytes to place in a heap binary. @@ -163,23 +164,6 @@ typedef union { #define ERL_ONHEAP_BIN_LIMIT 64 -/* - * This structure represents a SUB_BINARY. - * - * Note: The last field (orig) is not counted in arityval in the header. - * This simplifies garbage collection. - */ - -typedef struct erl_sub_bin { - Eterm thing_word; /* Subtag SUB_BINARY_SUBTAG. */ - Uint size; /* Binary size in bytes. */ - Uint offs; /* Offset into original binary. */ - byte bitsize; - byte bitoffs; - byte is_writable; /* The underlying binary is writable */ - Eterm orig; /* Original binary (REFC or HEAP binary). */ -} ErlSubBin; - #define ERL_SUB_BIN_SIZE (sizeof(ErlSubBin)/sizeof(Eterm)) #define HEADER_SUB_BIN _make_header(ERL_SUB_BIN_SIZE-2,_TAG_HEADER_SUB_BIN) diff --git a/erts/emulator/beam/erl_bits.h b/erts/emulator/beam/erl_bits.h index 4bd5b24157..1b4546722f 100644 --- a/erts/emulator/beam/erl_bits.h +++ b/erts/emulator/beam/erl_bits.h @@ -21,6 +21,23 @@ #ifndef __ERL_BITS_H__ #define __ERL_BITS_H__ +/* + * This structure represents a SUB_BINARY. + * + * Note: The last field (orig) is not counted in arityval in the header. + * This simplifies garbage collection. + */ + +typedef struct erl_sub_bin { + Eterm thing_word; /* Subtag SUB_BINARY_SUBTAG. */ + Uint size; /* Binary size in bytes. */ + Uint offs; /* Offset into original binary. */ + byte bitsize; + byte bitoffs; + byte is_writable; /* The underlying binary is writable */ + Eterm orig; /* Original binary (REFC or HEAP binary). */ +} ErlSubBin; + /* * This structure represents a binary to be matched. */ diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index 8cc7fc0142..26f6b6339d 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -3256,6 +3256,39 @@ reply_gc_info(void *vgcirp) gcireq_free(vgcirp); } +void erts_sub_binary_to_heap_binary(Eterm **pp, Eterm **hpp, Eterm *orig) { + Eterm *ptr = *pp; + Eterm *htop = *hpp; + Eterm gval; + ErlSubBin *sb = (ErlSubBin *)ptr; + ErlHeapBin *hb = (ErlHeapBin *)htop; + Eterm *real_bin; + byte *bs; + + real_bin = binary_val(follow_moved(sb->orig, (Eterm)0)); + + if (*real_bin == HEADER_PROC_BIN) { + bs = ((ProcBin *) real_bin)->bytes + sb->offs; + } else { + bs = (byte *)(&(((ErlHeapBin *) real_bin)->data)) + sb->offs; + } + + hb->thing_word = header_heap_bin(sb->size); + hb->size = sb->size; + sys_memcpy((byte *)hb->data, bs, sb->size); + + gval = make_boxed(htop); + *orig = gval; + *ptr = gval; + + ptr += ERL_SUB_BIN_SIZE; + htop += heap_bin_size(sb->size); + + *hpp = htop; + *pp = ptr; +} + + Eterm erts_gc_info_request(Process *c_p) { diff --git a/erts/emulator/beam/erl_gc.h b/erts/emulator/beam/erl_gc.h index 1cce426d21..2e2be2ee47 100644 --- a/erts/emulator/beam/erl_gc.h +++ b/erts/emulator/beam/erl_gc.h @@ -28,6 +28,8 @@ #define ERTS_POTENTIALLY_LONG_GC_HSIZE (128*1024) /* Words */ #include "erl_map.h" +#include "erl_fun.h" +#include "erl_bits.h" #define IS_MOVED_BOXED(x) (!is_header((x))) #define IS_MOVED_CONS(x) (is_non_value((x))) @@ -45,27 +47,53 @@ do { \ HTOP += 2; /* update tospace htop */ \ } while(0) -#define MOVE_BOXED(PTR,HDR,HTOP,ORIG) \ -do { \ - Eterm gval; \ - Sint nelts; \ - \ - ASSERT(is_header(HDR)); \ - nelts = header_arity(HDR); \ - switch ((HDR) & _HEADER_SUBTAG_MASK) { \ - case SUB_BINARY_SUBTAG: nelts++; break; \ - case MAP_SUBTAG: \ - if (is_flatmap_header(HDR)) nelts+=flatmap_get_size(PTR) + 1; \ - else nelts += hashmap_bitcount(MAP_HEADER_VAL(HDR)); \ - break; \ - case FUN_SUBTAG: nelts+=((ErlFunThing*)(PTR))->num_free+1; break; \ - } \ - gval = make_boxed(HTOP); \ - *ORIG = gval; \ - *HTOP++ = HDR; \ - *PTR++ = gval; \ - while (nelts--) *HTOP++ = *PTR++; \ -} while(0) +#define MOVE_BOXED(PTR,HDR,HTOP,ORIG) \ + do { \ + move_boxed(&(PTR), HDR, &(HTOP), ORIG); \ + } while(0) + +void erts_sub_binary_to_heap_binary(Eterm **pp, Eterm **hpp, Eterm *orig); +ERTS_GLB_INLINE void move_boxed(Eterm **pp, Eterm hdr, Eterm **hpp, Eterm *orig); + +#if ERTS_GLB_INLINE_INCL_FUNC_DEF +ERTS_GLB_INLINE void move_boxed(Eterm **pp, Eterm hdr, Eterm **hpp, Eterm *orig) +{ + Eterm gval; + Sint nelts; + Eterm *ptr = *pp; + Eterm *htop = *hpp; + + ASSERT(is_header(hdr)); + nelts = header_arity(hdr); + switch ((hdr) & _HEADER_SUBTAG_MASK) { + case SUB_BINARY_SUBTAG: + { + ErlSubBin *sb = (ErlSubBin *)ptr; + /* convert sub-binary to heap-binary if applicable */ + if (sb->bitsize == 0 && sb->bitoffs == 0 && + sb->is_writable == 0 && sb->size <= sizeof(Eterm) * 3) { + erts_sub_binary_to_heap_binary(pp, hpp, orig); + return; + } + } + nelts++; + break; + case MAP_SUBTAG: + if (is_flatmap_header(hdr)) nelts+=flatmap_get_size(ptr) + 1; + else nelts += hashmap_bitcount(MAP_HEADER_VAL(hdr)); + break; + case FUN_SUBTAG: nelts+=((ErlFunThing*)(ptr))->num_free+1; break; + } + gval = make_boxed(htop); + *orig = gval; + *htop++ = hdr; + *ptr++ = gval; + while (nelts--) *htop++ = *ptr++; + + *hpp = htop; + *pp = ptr; +} +#endif #define ErtsInYoungGen(TPtr, Ptr, OldHeap, OldHeapSz) \ (!erts_is_literal((TPtr), (Ptr)) \ -- cgit v1.2.3