From 4443bc775442d568357f72d96e2fbdae2ea58c3d Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 17 Jun 2016 05:11:29 +0200 Subject: make_preload: Save some memory by making preloaded code 'const' Mark the preloaded code 'const' to allow the compiler to put it into the 'text' segment instead of into the 'data' segment. Since the 'text' segment is shared among all instances of the Erlang virtual machine, this change could potentially reduce memory consumption (slightly). Before the change: $ size bin/x86_64-unknown-linux-gnu/beam.smp text data bss dec hex filename 2920246 352273 158472 3430991 345a4f bin/x86_64-unknown-linux-gnu/beam.smp After the change: $ size bin/x86_64-unknown-linux-gnu/beam.smp text data bss dec hex filename 3081046 191473 158472 3430991 345a4f bin/x86_64-unknown-linux-gnu/beam.smp Roughly speaking, this change cuts the size of the data segment in half. --- erts/emulator/utils/make_preload | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'erts') diff --git a/erts/emulator/utils/make_preload b/erts/emulator/utils/make_preload index f489bc2a39..8b629d9517 100755 --- a/erts/emulator/utils/make_preload +++ b/erts/emulator/utils/make_preload @@ -94,8 +94,8 @@ foreach $file (@ARGV) { close(FILE); push(@modules, " {\"$module\", " . length($_) . ", preloaded_$module},\n"); - print "unsigned preloaded_size_$module = ", length($_), ";\n"; - print "unsigned char preloaded_$module", "[] = {\n"; + print "const unsigned preloaded_size_$module = ", length($_), ";\n"; + print "const unsigned char preloaded_$module", "[] = {\n"; for ($i = 0; $i < length($_); $i++) { if ($i % 8 == 0 && $comment ne '') { $comment =~ s@/\*@..@g; # Comment start -- avoid warning. @@ -125,10 +125,10 @@ if ($gen_rc) { print @modules; print "END\n"; } elsif ($gen_old) { - print "struct {\n"; + print "const struct {\n"; print " char* name;\n"; print " int size;\n"; - print " unsigned char* code;\n"; + print " const unsigned char* code;\n"; print "} pre_loaded[] = {\n"; foreach (@modules) { print; -- cgit v1.2.3 From 6a6c72801e6fb021851b4f2591b03ed136a27363 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 17 Jun 2016 12:54:26 +0200 Subject: beam_makeops: Separate static information from counters The counters are only used in the special 'icount' emulator. We will save some memory by including the counters in the OpEntry. It will also make it possible to make opc 'const'. --- erts/emulator/beam/erl_bif_info.c | 2 +- erts/emulator/beam/erl_vm.h | 3 ++- erts/emulator/utils/beam_makeops | 13 +++++++++++-- 3 files changed, 14 insertions(+), 4 deletions(-) (limited to 'erts') diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c index 3fb866733c..e5d3f38ce4 100644 --- a/erts/emulator/beam/erl_bif_info.c +++ b/erts/emulator/beam/erl_bif_info.c @@ -2394,7 +2394,7 @@ BIF_RETTYPE system_info_1(BIF_ALIST_1) ERTS_ATOM_ENC_LATIN1, 1), erts_bld_uint(hpp, hszp, - opc[i].count)), + erts_instr_count[i])), res); } diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h index f97716d030..22c8e8ee12 100644 --- a/erts/emulator/beam/erl_vm.h +++ b/erts/emulator/beam/erl_vm.h @@ -146,12 +146,13 @@ typedef struct op_entry { int sz; /* Number of loaded words. */ char* pack; /* Instructions for packing engine. */ char* sign; /* Signature string. */ - unsigned count; /* Number of times executed. */ } OpEntry; extern OpEntry opc[]; /* Description of all instructions. */ extern int num_instructions; /* Number of instruction in opc[]. */ +extern Uint erts_instr_count[]; + /* some constants for various table sizes etc */ #define ATOM_TEXT_SIZE 32768 /* Increment for allocating atom text space */ diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops index 4407f7e289..acc0084145 100755 --- a/erts/emulator/utils/beam_makeops +++ b/erts/emulator/utils/beam_makeops @@ -566,7 +566,7 @@ sub emulator_output { $sep = ","; } $init .= "}"; - init_item($print_name, $init, $involves_r, $size, $pack, $sign, 0); + init_item($print_name, $init, $involves_r, $size, $pack, $sign); $op_to_name[$spec_opnum] = $instr; $spec_opnum++; } @@ -574,6 +574,15 @@ sub emulator_output { print "};\n\n"; print "int num_instructions = $spec_opnum;\n\n"; + # + # Print the array for instruction counts. + # + + print "#ifdef ERTS_OPCODE_COUNTER_SUPPORT\n"; + print "Uint erts_instr_count[$spec_opnum];\n"; + print "#endif\n"; + print "\n"; + # # Generate transformations. # @@ -708,7 +717,7 @@ sub emulator_output { print "#define DEFINE_COUNTING_LABELS"; for ($i = 0; $i < @op_to_name; $i++) { my($name) = $op_to_name[$i]; - print " \\\nCountCase($name): opc[$i].count++; goto lb_$name;"; + print " \\\nCountCase($name): erts_instr_count[$i]++; goto lb_$name;"; } print "\n\n"; -- cgit v1.2.3 From 644cc778e9770b847700dca41a0c3ebe20da64df Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= Date: Fri, 17 Jun 2016 05:23:08 +0200 Subject: beam_makeops: Save some memory by making loader tables 'const' Before: $ size bin/x86_64-unknown-linux-gnu/beam.smp text data bss dec hex filename 3080982 188369 158472 3427823 344def bin/x86_64-unknown-linux-gnu/beam.smp After: $ size bin/x86_64-unknown-linux-gnu/beam.smp text data bss dec hex filename 3164694 104657 158472 3427823 344def bin/x86_64-unknown-linux-gnu/beam.smp --- erts/emulator/beam/beam_load.c | 4 ++-- erts/emulator/beam/beam_load.h | 2 +- erts/emulator/beam/erl_vm.h | 4 ++-- erts/emulator/utils/beam_makeops | 14 +++++++------- 4 files changed, 12 insertions(+), 12 deletions(-) (limited to 'erts') diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c index 0c2743beb2..4ca2c6a13f 100644 --- a/erts/emulator/beam/beam_load.c +++ b/erts/emulator/beam/beam_load.c @@ -4860,7 +4860,7 @@ transform_engine(LoaderState* st) { Uint op; int ap; /* Current argument. */ - Uint* restart; /* Where to restart if current match fails. */ + const Uint* restart; /* Where to restart if current match fails. */ GenOpArg var[TE_MAX_VARS]; /* Buffer for variables. */ GenOpArg* rest_args = NULL; int num_rest_args = 0; @@ -4869,7 +4869,7 @@ transform_engine(LoaderState* st) GenOp* instr; GenOp* first = st->genop; GenOp* keep = NULL; - Uint* pc; + const Uint* pc; static Uint restart_fail[1] = {TOP_fail}; ASSERT(gen_opc[first->op].transform != -1); diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h index fd2dd97fee..92a9abddbf 100644 --- a/erts/emulator/beam/beam_load.h +++ b/erts/emulator/beam/beam_load.h @@ -35,7 +35,7 @@ typedef struct gen_op_entry { int transform; } GenOpEntry; -extern GenOpEntry gen_opc[]; +extern const GenOpEntry gen_opc[]; #ifdef NO_JUMP_TABLE #define BeamOp(Op) (Op) diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h index 22c8e8ee12..60c2349f36 100644 --- a/erts/emulator/beam/erl_vm.h +++ b/erts/emulator/beam/erl_vm.h @@ -148,8 +148,8 @@ typedef struct op_entry { char* sign; /* Signature string. */ } OpEntry; -extern OpEntry opc[]; /* Description of all instructions. */ -extern int num_instructions; /* Number of instruction in opc[]. */ +extern const OpEntry opc[]; /* Description of all instructions. */ +extern const int num_instructions; /* Number of instruction in opc[]. */ extern Uint erts_instr_count[]; diff --git a/erts/emulator/utils/beam_makeops b/erts/emulator/utils/beam_makeops index acc0084145..9813142585 100755 --- a/erts/emulator/utils/beam_makeops +++ b/erts/emulator/utils/beam_makeops @@ -475,7 +475,7 @@ sub emulator_output { print '#include "beam_load.h"', "\n"; print "\n"; - print "char tag_to_letter[] = {\n "; + print "const char tag_to_letter[] = {\n "; for ($i = 0; $i < length($genop_types); $i++) { print "'$tag_type[$i]', "; } @@ -489,7 +489,7 @@ sub emulator_output { # Generate code for specific ops. # my($spec_opnum) = 0; - print "OpEntry opc[] = {\n"; + print "const OpEntry opc[] = {\n"; foreach $key (sort keys %specific_op) { $gen_to_spec{$key} = $spec_opnum; $num_specific{$key} = @{$specific_op{$key}}; @@ -572,7 +572,7 @@ sub emulator_output { } } print "};\n\n"; - print "int num_instructions = $spec_opnum;\n\n"; + print "const int num_instructions = $spec_opnum;\n\n"; # # Print the array for instruction counts. @@ -593,7 +593,7 @@ sub emulator_output { # Print the generic instruction table. # - print "GenOpEntry gen_opc[] = {\n"; + print "const GenOpEntry gen_opc[] = {\n"; for ($i = 0; $i < @gen_opname; $i++) { if ($i == $num_file_opcodes) { print "\n/*\n * Internal generic instructions.\n */\n\n"; @@ -687,8 +687,8 @@ sub emulator_output { print "#define TE_MAX_VARS $te_max_vars\n"; print "\n"; - print "extern char tag_to_letter[];\n"; - print "extern Uint op_transform[];\n"; + print "extern const char tag_to_letter[];\n"; + print "extern const Uint op_transform[];\n"; print "\n"; for ($i = 0; $i < @op_to_name; $i++) { @@ -1426,7 +1426,7 @@ sub tr_gen { # Print the generated transformation engine. # my($offset) = 0; - print "Uint op_transform[] = {\n"; + print "const Uint op_transform[] = {\n"; foreach $key (sort keys %gen_transform) { $gen_transform_offset{$key} = $offset; my @instr = @{$gen_transform{$key}}; -- cgit v1.2.3