bpart: Track whether any binding replacement has happened in image modules (#57433)

Keno · KristofferC · commit 5e3f967e9666 · 2025-02-17T19:36:33.000+01:00
This implements the optimization proposed in #57426 by keeping track of whether any bindings were replaced in image modules (excluding `Main` as facilitated by #57426). In addition, we augment serialization to keep track of whether a method body contains any GlobalRefs that point to a loaded (system or package) image. If both of these flags are true, we can skip scanning the body of the method, since we know that we neither need to add any additional backedges nor were any of the referenced bindings invalidated. The performance impact on end-to-end load time is small, but measurable. Overall `@time using ModelingToolkit` consistently improves about 5% using this PR. However, I should note that using time is still about 40% slower than 1.11. This is not necessarily an Apples-to-Apples comparison as there were substantial other changes on 1.12 (as well as current load-time-tunings targeting older versions), but I wanted to put the number context. (cherry picked from commit f6e2b98)
diff --git a/base/client.jl b/base/client.jl
@@ -265,7 +265,7 @@ function exec_options(opts)
     distributed_mode = (opts.worker == 1) || (opts.nprocs > 0) || (opts.machine_file != C_NULL)
     if distributed_mode
         let Distributed = require(PkgId(UUID((0x8ba89e20_285c_5b6f, 0x9357_94700520ee1b)), "Distributed"))
-            Core.eval(MainInclude, :(const Distributed = $Distributed))
+            MainInclude.Distributed = Distributed
             Core.eval(Main, :(using Base.MainInclude.Distributed))
             invokelatest(Distributed.process_opts, opts)
         end
@@ -400,7 +400,7 @@ function load_InteractiveUtils(mod::Module=Main)
         try
             # TODO: we have to use require_stdlib here because it is a dependency of REPL, but we would sort of prefer not to
             let InteractiveUtils = require_stdlib(PkgId(UUID(0xb77e0a4c_d291_57a0_90e8_8db25a27a240), "InteractiveUtils"))
-                Core.eval(MainInclude, :(const InteractiveUtils = $InteractiveUtils))
+                MainInclude.InteractiveUtils = InteractiveUtils
             end
         catch ex
             @warn "Failed to import InteractiveUtils into module $mod" exception=(ex, catch_backtrace())
@@ -535,6 +535,10 @@ The thrown errors are collected in a stack of exceptions.
 """
 global err = nothing
 
+# Used for memoizing require_stdlib of these modules
+global InteractiveUtils::Module
+global Distributed::Module
+
 # weakly exposes ans and err variables to Main
 export ans, err
 end
diff --git a/base/invalidation.jl b/base/invalidation.jl
@@ -180,26 +180,34 @@ function binding_was_invalidated(b::Core.Binding)
     b.partitions.min_world > unsafe_load(cglobal(:jl_require_world, UInt))
 end
 
-function scan_new_method!(methods_with_invalidated_source::IdSet{Method}, method::Method)
+function scan_new_method!(methods_with_invalidated_source::IdSet{Method}, method::Method, image_backedges_only::Bool)
     isdefined(method, :source) || return
+    if image_backedges_only && !has_image_globalref(method)
+        return
+    end
     src = _uncompressed_ir(method)
     mod = method.module
     foreachgr(src) do gr::GlobalRef
         b = convert(Core.Binding, gr)
-        binding_was_invalidated(b) && push!(methods_with_invalidated_source, method)
+        if binding_was_invalidated(b)
+            # TODO: We could turn this into an addition if condition. For now, use it as a reasonably cheap
+            # additional consistency chekc
+            @assert !image_backedges_only
+            push!(methods_with_invalidated_source, method)
+        end
         maybe_add_binding_backedge!(b, method)
     end
 end
 
-function scan_new_methods(extext_methods::Vector{Any}, internal_methods::Vector{Any})
+function scan_new_methods(extext_methods::Vector{Any}, internal_methods::Vector{Any}, image_backedges_only::Bool)
     methods_with_invalidated_source = IdSet{Method}()
     for method in internal_methods
         if isa(method, Method)
-           scan_new_method!(methods_with_invalidated_source, method)
+           scan_new_method!(methods_with_invalidated_source, method, image_backedges_only)
         end
     end
     for tme::Core.TypeMapEntry in extext_methods
-        scan_new_method!(methods_with_invalidated_source, tme.func::Method)
+        scan_new_method!(methods_with_invalidated_source, tme.func::Method, image_backedges_only)
     end
     return methods_with_invalidated_source
 end
diff --git a/base/runtime_internals.jl b/base/runtime_internals.jl
@@ -1656,3 +1656,5 @@ isempty(mt::Core.MethodTable) = (mt.defs === nothing)
 uncompressed_ir(m::Method) = isdefined(m, :source) ? _uncompressed_ir(m) :
                              isdefined(m, :generator) ? error("Method is @generated; try `code_lowered` instead.") :
                              error("Code for this Method is not available.")
+
+has_image_globalref(m::Method) = ccall(:jl_ir_flag_has_image_globalref, Bool, (Any,), m.source)
diff --git a/base/staticdata.jl b/base/staticdata.jl
@@ -25,7 +25,8 @@ end
 function insert_backedges(edges::Vector{Any}, ext_ci_list::Union{Nothing,Vector{Any}}, extext_methods::Vector{Any}, internal_methods::Vector{Any})
     # determine which CodeInstance objects are still valid in our image
     # to enable any applicable new codes
-    methods_with_invalidated_source = Base.scan_new_methods(extext_methods, internal_methods)
+    backedges_only = unsafe_load(cglobal(:jl_first_image_replacement_world, UInt)) == typemax(UInt)
+    methods_with_invalidated_source = Base.scan_new_methods(extext_methods, internal_methods, backedges_only)
     stack = CodeInstance[]
     visiting = IdDict{CodeInstance,Int}()
     _insert_backedges(edges, stack, visiting, methods_with_invalidated_source)
diff --git a/src/ircode.c b/src/ircode.c
@@ -547,14 +547,15 @@ static void jl_encode_value_(jl_ircode_state *s, jl_value_t *v, int as_literal)
     }
 }
 
-static jl_code_info_flags_t code_info_flags(uint8_t propagate_inbounds, uint8_t has_fcall,
+static jl_code_info_flags_t code_info_flags(uint8_t propagate_inbounds, uint8_t has_fcall, uint8_t has_image_globalref,
                                             uint8_t nospecializeinfer, uint8_t isva,
                                             uint8_t inlining, uint8_t constprop, uint8_t nargsmatchesmethod,
                                             jl_array_t *ssaflags)
 {
     jl_code_info_flags_t flags;
     flags.bits.propagate_inbounds = propagate_inbounds;
     flags.bits.has_fcall = has_fcall;
+    flags.bits.has_image_globalref = has_image_globalref;
     flags.bits.nospecializeinfer = nospecializeinfer;
     flags.bits.isva = isva;
     flags.bits.inlining = inlining;
@@ -1036,7 +1037,7 @@ JL_DLLEXPORT jl_string_t *jl_compress_ir(jl_method_t *m, jl_code_info_t *code)
     };
 
     uint8_t nargsmatchesmethod = code->nargs == m->nargs;
-    jl_code_info_flags_t flags = code_info_flags(code->propagate_inbounds, code->has_fcall,
+    jl_code_info_flags_t flags = code_info_flags(code->propagate_inbounds, code->has_fcall, code->has_image_globalref,
                                                  code->nospecializeinfer, code->isva,
                                                  code->inlining, code->constprop,
                                                  nargsmatchesmethod,
@@ -1134,6 +1135,7 @@ JL_DLLEXPORT jl_code_info_t *jl_uncompress_ir(jl_method_t *m, jl_code_instance_t
     code->constprop = flags.bits.constprop;
     code->propagate_inbounds = flags.bits.propagate_inbounds;
     code->has_fcall = flags.bits.has_fcall;
+    code->has_image_globalref = flags.bits.has_image_globalref;
     code->nospecializeinfer = flags.bits.nospecializeinfer;
     code->isva = flags.bits.isva;
     code->purity.bits = read_uint16(s.s);
@@ -1228,6 +1230,16 @@ JL_DLLEXPORT uint8_t jl_ir_flag_has_fcall(jl_string_t *data)
     return flags.bits.has_fcall;
 }
 
+JL_DLLEXPORT uint8_t jl_ir_flag_has_image_globalref(jl_string_t *data)
+{
+    if (jl_is_code_info(data))
+        return ((jl_code_info_t*)data)->has_image_globalref;
+    assert(jl_is_string(data));
+    jl_code_info_flags_t flags;
+    flags.packed = jl_string_data(data)[ir_offset_flags];
+    return flags.bits.has_image_globalref;
+}
+
 JL_DLLEXPORT uint16_t jl_ir_inlining_cost(jl_string_t *data)
 {
     if (jl_is_code_info(data))
diff --git a/src/jltypes.c b/src/jltypes.c
@@ -3485,7 +3485,7 @@ void jl_init_types(void) JL_GC_DISABLED
     jl_code_info_type =
         jl_new_datatype(jl_symbol("CodeInfo"), core,
                         jl_any_type, jl_emptysvec,
-                        jl_perm_symsvec(22,
+                        jl_perm_symsvec(23,
                             "code",
                             "debuginfo",
                             "ssavaluetypes",
@@ -3502,13 +3502,14 @@ void jl_init_types(void) JL_GC_DISABLED
                             "nargs",
                             "propagate_inbounds",
                             "has_fcall",
+                            "has_image_globalref",
                             "nospecializeinfer",
                             "isva",
                             "inlining",
                             "constprop",
                             "purity",
                             "inlining_cost"),
-                        jl_svec(22,
+                        jl_svec(23,
                             jl_array_any_type,
                             jl_debuginfo_type,
                             jl_any_type,
@@ -3527,6 +3528,7 @@ void jl_init_types(void) JL_GC_DISABLED
                             jl_bool_type,
                             jl_bool_type,
                             jl_bool_type,
+                            jl_bool_type,
                             jl_uint8_type,
                             jl_uint8_type,
                             jl_uint16_type,
diff --git a/src/julia.h b/src/julia.h
@@ -312,6 +312,7 @@ typedef struct _jl_code_info_t {
     // various boolean properties:
     uint8_t propagate_inbounds;
     uint8_t has_fcall;
+    uint8_t has_image_globalref;
     uint8_t nospecializeinfer;
     uint8_t isva;
     // uint8 settings
@@ -2263,6 +2264,7 @@ JL_DLLEXPORT jl_value_t *jl_compress_ir(jl_method_t *m, jl_code_info_t *code);
 JL_DLLEXPORT jl_code_info_t *jl_uncompress_ir(jl_method_t *m, jl_code_instance_t *metadata, jl_value_t *data);
 JL_DLLEXPORT uint8_t jl_ir_flag_inlining(jl_value_t *data) JL_NOTSAFEPOINT;
 JL_DLLEXPORT uint8_t jl_ir_flag_has_fcall(jl_value_t *data) JL_NOTSAFEPOINT;
+JL_DLLEXPORT uint8_t jl_ir_flag_has_image_globalref(jl_value_t *data) JL_NOTSAFEPOINT;
 JL_DLLEXPORT uint16_t jl_ir_inlining_cost(jl_value_t *data) JL_NOTSAFEPOINT;
 JL_DLLEXPORT ssize_t jl_ir_nslots(jl_value_t *data) JL_NOTSAFEPOINT;
 JL_DLLEXPORT uint8_t jl_ir_slotflag(jl_value_t *data, size_t i) JL_NOTSAFEPOINT;
diff --git a/src/julia_internal.h b/src/julia_internal.h
@@ -650,6 +650,7 @@ STATIC_INLINE jl_value_t *undefref_check(jl_datatype_t *dt, jl_value_t *v) JL_NO
 typedef struct {
     uint16_t propagate_inbounds:1;
     uint16_t has_fcall:1;
+    uint16_t has_image_globalref:1;
     uint16_t nospecializeinfer:1;
     uint16_t isva:1;
     uint16_t nargsmatchesmethod:1;
diff --git a/src/method.c b/src/method.c
@@ -486,6 +486,11 @@ jl_code_info_t *jl_new_code_info_from_ir(jl_expr_t *ir)
             is_flag_stmt = 1;
         else if (jl_is_expr(st) && ((jl_expr_t*)st)->head == jl_return_sym)
             jl_array_ptr_set(body, j, jl_new_struct(jl_returnnode_type, jl_exprarg(st, 0)));
+        else if (jl_is_globalref(st)) {
+            jl_globalref_t *gr = (jl_globalref_t*)st;
+            if (jl_object_in_image((jl_value_t*)gr->mod))
+                li->has_image_globalref = 1;
+        }
         else {
             if (jl_is_expr(st) && ((jl_expr_t*)st)->head == jl_assign_sym)
                 st = jl_exprarg(st, 1);
@@ -593,6 +598,7 @@ JL_DLLEXPORT jl_code_info_t *jl_new_code_info_uninit(void)
     src->max_world = ~(size_t)0;
     src->propagate_inbounds = 0;
     src->has_fcall = 0;
+    src->has_image_globalref = 0;
     src->nospecializeinfer = 0;
     src->constprop = 0;
     src->inlining = 0;
diff --git a/src/module.c b/src/module.c
@@ -1294,10 +1294,19 @@ JL_DLLEXPORT jl_binding_partition_t *jl_replace_binding_locked(jl_binding_t *b,
         new_world);
 }
 
+extern JL_DLLEXPORT _Atomic(size_t) jl_first_image_replacement_world;
 JL_DLLEXPORT jl_binding_partition_t *jl_replace_binding_locked2(jl_binding_t *b,
     jl_binding_partition_t *old_bpart, jl_value_t *restriction_val, size_t kind, size_t new_world)
 {
     check_safe_newbinding(b->globalref->mod, b->globalref->name);
+
+    // Check if this is a replacing a binding in the system or a package image.
+    // Until the first such replacement, we can fast-path validation.
+    // For these purposes, we consider the `Main` module to be a non-sysimg module.
+    // This is legal, because we special case the `Main` in check_safe_import_from.
+    if (jl_object_in_image((jl_value_t*)b) && b->globalref->mod != jl_main_module && jl_atomic_load_relaxed(&jl_first_image_replacement_world) == ~(size_t)0)
+        jl_atomic_store_relaxed(&jl_first_image_replacement_world, new_world);
+
     assert(jl_atomic_load_relaxed(&b->partitions) == old_bpart);
     jl_atomic_store_release(&old_bpart->max_world, new_world-1);
     jl_binding_partition_t *new_bpart = new_binding_partition();
diff --git a/src/staticdata.c b/src/staticdata.c
@@ -90,6 +90,7 @@ External links:
 
 static const size_t WORLD_AGE_REVALIDATION_SENTINEL = 0x1;
 JL_DLLEXPORT size_t jl_require_world = ~(size_t)0;
+JL_DLLEXPORT _Atomic(size_t) jl_first_image_replacement_world = ~(size_t)0;
 
 #include "staticdata_utils.c"
 #include "precompile_utils.c"
@@ -3541,7 +3542,7 @@ extern void export_jl_small_typeof(void);
 int IMAGE_NATIVE_CODE_TAINTED = 0;
 
 // TODO: This should possibly be in Julia
-static int jl_validate_binding_partition(jl_binding_t *b, jl_binding_partition_t *bpart, size_t mod_idx, int unchanged_implicit)
+static int jl_validate_binding_partition(jl_binding_t *b, jl_binding_partition_t *bpart, size_t mod_idx, int unchanged_implicit, int no_replacement)
 {
     if (jl_atomic_load_relaxed(&bpart->max_world) != ~(size_t)0)
         return 1;
@@ -3556,10 +3557,13 @@ static int jl_validate_binding_partition(jl_binding_t *b, jl_binding_partition_t
     if (!jl_bkind_is_some_import(kind))
         return 1;
     jl_binding_t *imported_binding = (jl_binding_t*)bpart->restriction;
+    if (no_replacement)
+        goto add_backedge;
     jl_binding_partition_t *latest_imported_bpart = jl_atomic_load_relaxed(&imported_binding->partitions);
     if (!latest_imported_bpart)
         return 1;
     if (latest_imported_bpart->min_world <= bpart->min_world) {
+add_backedge:
         // Imported binding is still valid
         if ((kind == BINDING_KIND_EXPLICIT || kind == BINDING_KIND_IMPORTED) &&
                 external_blob_index((jl_value_t*)imported_binding) != mod_idx) {
@@ -3583,7 +3587,7 @@ static int jl_validate_binding_partition(jl_binding_t *b, jl_binding_partition_t
             jl_binding_t *bedge = (jl_binding_t*)edge;
             if (!jl_atomic_load_relaxed(&bedge->partitions))
                 continue;
-            jl_validate_binding_partition(bedge, jl_atomic_load_relaxed(&bedge->partitions), mod_idx, 0);
+            jl_validate_binding_partition(bedge, jl_atomic_load_relaxed(&bedge->partitions), mod_idx, 0, 0);
         }
     }
     if (bpart->kind & BINDING_FLAG_EXPORTED) {
@@ -3600,7 +3604,7 @@ static int jl_validate_binding_partition(jl_binding_t *b, jl_binding_partition_t
                 if (!jl_atomic_load_relaxed(&importee->partitions))
                     continue;
                 JL_UNLOCK(&mod->lock);
-                jl_validate_binding_partition(importee, jl_atomic_load_relaxed(&importee->partitions), mod_idx, 0);
+                jl_validate_binding_partition(importee, jl_atomic_load_relaxed(&importee->partitions), mod_idx, 0, 0);
                 JL_LOCK(&mod->lock);
             }
         }
@@ -4070,22 +4074,21 @@ static void jl_restore_system_image_from_stream_(ios_t *f, jl_image_t *image, jl
         }
     }
     if (s.incremental) {
-        // This needs to be done in a second pass after the binding partitions
-        // have the proper ABI again.
+        int no_replacement = jl_atomic_load_relaxed(&jl_first_image_replacement_world) == ~(size_t)0;
         for (size_t i = 0; i < s.fixup_objs.len; i++) {
             uintptr_t item = (uintptr_t)s.fixup_objs.items[i];
             jl_value_t *obj = (jl_value_t*)(image_base + item);
             if (jl_is_module(obj)) {
                 jl_module_t *mod = (jl_module_t*)obj;
                 size_t mod_idx = external_blob_index((jl_value_t*)mod);
                 jl_svec_t *table = jl_atomic_load_relaxed(&mod->bindings);
-                int unchanged_implicit = all_usings_unchanged_implicit(mod);
+                int unchanged_implicit = no_replacement || all_usings_unchanged_implicit(mod);
                 for (size_t i = 0; i < jl_svec_len(table); i++) {
                     jl_binding_t *b = (jl_binding_t*)jl_svecref(table, i);
                     if ((jl_value_t*)b == jl_nothing)
                         continue;
                     jl_binding_partition_t *bpart = jl_atomic_load_relaxed(&b->partitions);
-                    if (!jl_validate_binding_partition(b, bpart, mod_idx, unchanged_implicit)) {
+                    if (!jl_validate_binding_partition(b, bpart, mod_idx, unchanged_implicit, no_replacement)) {
                         unchanged_implicit = all_usings_unchanged_implicit(mod);
                     }
                 }
diff --git a/stdlib/Serialization/src/Serialization.jl b/stdlib/Serialization/src/Serialization.jl
@@ -80,7 +80,7 @@ const TAGS = Any[
 const NTAGS = length(TAGS)
 @assert NTAGS == 255
 
-const ser_version = 29 # do not make changes without bumping the version #!
+const ser_version = 30 # do not make changes without bumping the version #!
 
 format_version(::AbstractSerializer) = ser_version
 format_version(s::Serializer) = s.version
@@ -1268,6 +1268,9 @@ function deserialize(s::AbstractSerializer, ::Type{CodeInfo})
     if format_version(s) >= 20
         ci.has_fcall = deserialize(s)
     end
+    if format_version(s) >= 30
+        ci.has_image_globalref = deserialize(s)::Bool
+    end
     if format_version(s) >= 24
         ci.nospecializeinfer = deserialize(s)::Bool
     end
diff --git a/test/rebinding.jl b/test/rebinding.jl
@@ -221,3 +221,52 @@ module Regression
     end
     @test GeoParams57377.B.C.h() == GeoParams57377.B.C.S()
 end
+
+# Test that the validation bypass fast path is not defeated by loading InteractiveUtils
+@test parse(UInt, readchomp(`$(Base.julia_cmd()) -e 'using InteractiveUtils; show(unsafe_load(cglobal(:jl_first_image_replacement_world, UInt)))'`)) == typemax(UInt)
+
+# Test that imported module binding backedges are still added in a new module that has the fast path active
+let test_code =
+    """
+    using Test
+    @assert unsafe_load(cglobal(:jl_first_image_replacement_world, UInt)) == typemax(UInt)
+    include("precompile_utils.jl")
+
+    precompile_test_harness("rebinding precompile") do load_path
+        write(joinpath(load_path, "LotsOfBindingsToDelete2.jl"),
+              "module LotsOfBindingsToDelete2
+                 const delete_me_6 = 6
+               end")
+        Base.compilecache(Base.PkgId("LotsOfBindingsToDelete2"))
+        write(joinpath(load_path, "UseTheBindings2.jl"),
+              "module UseTheBindings2
+                 import LotsOfBindingsToDelete2: delete_me_6
+                 f_use_bindings6() = delete_me_6
+                 # Code Instances for each of these
+                 @assert (f_use_bindings6(),) == (6,)
+               end")
+        Base.compilecache(Base.PkgId("UseTheBindings2"))
+        @eval using LotsOfBindingsToDelete2
+        @eval using UseTheBindings2
+        invokelatest() do
+            @test UseTheBindings2.f_use_bindings6() == 6
+            Base.delete_binding(LotsOfBindingsToDelete2, :delete_me_6)
+            invokelatest() do
+                @test_throws UndefVarError UseTheBindings2.f_use_bindings6()
+            end
+        end
+    end
+
+    finish_precompile_test!()
+    """
+    @test success(pipeline(`$(Base.julia_cmd()) -e $test_code`; stderr))
+end
+
+# Image Globalref smoke test
+module ImageGlobalRefFlag
+    using Test
+    @eval fimage() = $(GlobalRef(Base, :sin))
+    fnoimage() = x
+    @test Base.has_image_globalref(first(methods(fimage)))
+    @test !Base.has_image_globalref(first(methods(fnoimage)))
+end
