From 971d054018d94dd89c2323e237f9c6c3afa91e3b Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Wed, 28 Nov 2012 17:58:23 +0100 Subject: erts: Make gc sizes fit into MB Carrier blocks * Account for block header size in gc-sizes * Also slow down growth to 20% instead of 25% when size threshold is reached --- erts/emulator/beam/erl_gc.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'erts/emulator/beam/erl_gc.c') diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index 6075a527c3..cf06cedf7f 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -168,15 +168,21 @@ erts_init_gc(void) * we really don't want that growth when the heaps are that big. */ - heap_sizes[0] = 34; - heap_sizes[1] = 55; - for (i = 2; i < 23; i++) { - heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-2]; + /* Growth stage 1 - Fibonacci + 1*/ + /* 12,38 will hit size 233, the old default */ + + heap_sizes[0] = 12; + heap_sizes[1] = 38; + + for(i = 2; i < 23; i++) { + /* one extra word for block header */ + heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-2] + 1; } + /* Growth stage 2 - 20% growth */ /* At 1.3 mega words heap, we start to slow down. */ for (i = 23; i < ALENGTH(heap_sizes); i++) { - heap_sizes[i] = 5*(heap_sizes[i-1]/4); + heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-1]/5; if (heap_sizes[i] < 0) { /* Size turned negative. Discard this last size. */ i--; -- cgit v1.2.3 From 53cabc7eda09dbe38df565cbf87d2f1ab3cd68e4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn-Egil=20Dahlberg?= Date: Fri, 7 Dec 2012 17:41:42 +0100 Subject: erts: Reduce max heap sizes Reduces max heap sizes to max addressable memory space. In reality this could be even less since we need at least twice as much adressable memory to do a garbage collection. The rest of the system also uses memory thus further constraining heap memory space and in the 64 bit case we really only have 48 bits mappable memory. --- erts/emulator/beam/erl_gc.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) (limited to 'erts/emulator/beam/erl_gc.c') diff --git a/erts/emulator/beam/erl_gc.c b/erts/emulator/beam/erl_gc.c index cf06cedf7f..2917f6526a 100644 --- a/erts/emulator/beam/erl_gc.c +++ b/erts/emulator/beam/erl_gc.c @@ -129,7 +129,7 @@ static void disallow_heap_frag_ref(Process* p, Eterm* n_htop, Eterm* objv, int n #if defined(ARCH_64) && !HALFWORD_HEAP # define MAX_HEAP_SIZES 154 #else -# define MAX_HEAP_SIZES 55 +# define MAX_HEAP_SIZES 59 #endif static Sint heap_sizes[MAX_HEAP_SIZES]; /* Suitable heap sizes. */ @@ -144,6 +144,7 @@ void erts_init_gc(void) { int i = 0; + Sint max_heap_size = 0; ASSERT(offsetof(ProcBin,thing_word) == offsetof(struct erl_off_heap_header,thing_word)); ASSERT(offsetof(ProcBin,thing_word) == offsetof(ErlFunThing,thing_word)); @@ -179,11 +180,19 @@ erts_init_gc(void) heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-2] + 1; } + + /* for 32 bit we want max_heap_size to be MAX(32bit) / 4 [words] (and halfword) + * for 64 bit we want max_heap_size to be MAX(52bit) / 8 [words] + */ + + max_heap_size = sizeof(Eterm) < 8 ? (Sint)((~(Uint)0)/(sizeof(Eterm))) : + (Sint)(((Uint64)1 << 53)/sizeof(Eterm)); + /* Growth stage 2 - 20% growth */ /* At 1.3 mega words heap, we start to slow down. */ for (i = 23; i < ALENGTH(heap_sizes); i++) { heap_sizes[i] = heap_sizes[i-1] + heap_sizes[i-1]/5; - if (heap_sizes[i] < 0) { + if ((heap_sizes[i] < 0) || heap_sizes[i] > max_heap_size) { /* Size turned negative. Discard this last size. */ i--; break; @@ -860,14 +869,12 @@ minor_collection(Process* p, int need, Eterm* objv, int nobj, Uint *recl) } } - if (wanted < MIN_HEAP_SIZE(p)) { - wanted = MIN_HEAP_SIZE(p); - } else { - wanted = next_heap_size(p, wanted, 0); - } + wanted = wanted < MIN_HEAP_SIZE(p) ? MIN_HEAP_SIZE(p) + : next_heap_size(p, wanted, 0); if (wanted < HEAP_SIZE(p)) { shrink_new_heap(p, wanted, objv, nobj); } + ASSERT(HEAP_SIZE(p) == next_heap_size(p, HEAP_SIZE(p), 0)); return 1; /* We are done. */ } @@ -1426,11 +1433,10 @@ adjust_after_fullsweep(Process *p, Uint size_before, int need, Eterm *objv, int I think this is better as fullsweep is used mainly on small memory systems, but I could be wrong... */ wanted = 2 * need_after; - if (wanted < p->min_heap_size) { - sz = p->min_heap_size; - } else { - sz = next_heap_size(p, wanted, 0); - } + + sz = wanted < p->min_heap_size ? p->min_heap_size + : next_heap_size(p, wanted, 0); + if (sz < HEAP_SIZE(p)) { shrink_new_heap(p, sz, objv, nobj); } -- cgit v1.2.3