ruby-changes:71373
From: nagachika <ko1@a...>
Date: Sat, 12 Mar 2022 16:54:15 +0900 (JST)
Subject: [ruby-changes:71373] 3ce60f44b8 (ruby_3_0): merge revision(s) 0130e17a410d60a10e7041ce98748b8de6946971,32b7dcfb56a417c1d1c354102351fc1825d653bf,79cc566ab4cdf75f125ecf413a27d353a9756c08: [Backport #18394]
https://git.ruby-lang.org/ruby.git/commit/?id=3ce60f44b8 From 3ce60f44b8de3aabb31c37d2afd2a622a64a3e6f Mon Sep 17 00:00:00 2001 From: nagachika <nagachika@r...> Date: Sat, 12 Mar 2022 15:58:42 +0900 Subject: merge revision(s) 0130e17a410d60a10e7041ce98748b8de6946971,32b7dcfb56a417c1d1c354102351fc1825d653bf,79cc566ab4cdf75f125ecf413a27d353a9756c08: [Backport #18394] Always enabled read barrier even on GC.compact Some objects can survive the GC before compaction, but get collected in the second compaction. This means we could have objects reference T_MOVED during "free" in the second, compacting GC. If that is the case, we need to invalidate those "moved" addresses. Invalidation is done via read barrier, so we need to make sure the read barrier is active even during `GC.compact`. This also means we don't actually need to do one GC before compaction, we can just do the compaction and GC in one step. --- gc.c | 20 +++----------------- 1 file changed, 3 insertions(+), 17 deletions(-) Fix more assumptions about the read barrier This is a continuation of 0130e17a410d60a10e7041ce98748b8de6946971. We need to always use the read barrier --- gc.c | 10 ---------- 1 file changed, 10 deletions(-) Make during_compacting flag in GC one bit Commit c32218de1ba094223420a4ea017707f48d0009c5 turned during_compacting flag to 2 bits to support the case when there is no write barrier. But commit 32b7dcfb56a417c1d1c354102351fc1825d653bf changed compaction to always enable the write barrier. This commit cleans up some of the leftover code. --- gc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- gc.c | 34 +++++----------------------------- version.h | 2 +- 2 files changed, 6 insertions(+), 30 deletions(-) diff --git a/gc.c b/gc.c index e5f152a870..4f04c22990 100644 --- a/gc.c +++ b/gc.c @@ -679,7 +679,7 @@ typedef struct rb_objspace { https://github.com/ruby/ruby/blob/trunk/gc.c#L679 unsigned int dont_gc : 1; unsigned int dont_incremental : 1; unsigned int during_gc : 1; - unsigned int during_compacting : 2; + unsigned int during_compacting : 1; unsigned int gc_stressful: 1; unsigned int has_hook: 1; unsigned int during_minor_gc : 1; @@ -4479,11 +4479,6 @@ static VALUE gc_move(rb_objspace_t *objspace, VALUE scan, VALUE free); https://github.com/ruby/ruby/blob/trunk/gc.c#L4479 static void lock_page_body(rb_objspace_t *objspace, struct heap_page_body *body) { - /* If this is an explicit compaction (GC.compact), we don't need a read - * barrier, so just return early. */ - if (objspace->flags.during_compacting >> 1) { - return; - } #if defined(_WIN32) DWORD old_protect; @@ -4500,11 +4495,6 @@ lock_page_body(rb_objspace_t *objspace, struct heap_page_body *body) https://github.com/ruby/ruby/blob/trunk/gc.c#L4495 static void unlock_page_body(rb_objspace_t *objspace, struct heap_page_body *body) { - /* If this is an explicit compaction (GC.compact), we don't need a read - * barrier, so just return early. */ - if (objspace->flags.during_compacting >> 1) { - return; - } #if defined(_WIN32) DWORD old_protect; @@ -4746,12 +4736,8 @@ gc_compact_finish(rb_objspace_t *objspace, rb_heap_t *heap) https://github.com/ruby/ruby/blob/trunk/gc.c#L4736 { GC_ASSERT(heap->sweeping_page == heap->compact_cursor); - /* If this is an explicit compaction (GC.compact), no read barrier was set - * so we don't need to unprotect pages or uninstall the SEGV handler */ - if (!(objspace->flags.during_compacting >> 1)) { - gc_unprotect_pages(objspace, heap); - uninstall_handlers(); - } + gc_unprotect_pages(objspace, heap); + uninstall_handlers(); /* The mutator is allowed to run during incremental sweeping. T_MOVED * objects can get pushed on the stack and when the compaction process @@ -5255,12 +5241,6 @@ gc_compact_start(rb_objspace_t *objspace, rb_heap_t *heap) https://github.com/ruby/ruby/blob/trunk/gc.c#L5241 memset(objspace->rcompactor.considered_count_table, 0, T_MASK * sizeof(size_t)); memset(objspace->rcompactor.moved_count_table, 0, T_MASK * sizeof(size_t)); - /* If this is an explicit compaction (GC.compact), we don't need a read - * barrier, so just return early. */ - if (objspace->flags.during_compacting >> 1) { - return; - } - /* Set up read barrier for pages containing MOVED objects */ install_handlers(); } @@ -8236,7 +8216,7 @@ gc_start(rb_objspace_t *objspace, int reason) https://github.com/ruby/ruby/blob/trunk/gc.c#L8216 objspace->flags.immediate_sweep = !!((unsigned)reason & GPR_FLAG_IMMEDIATE_SWEEP); /* Explicitly enable compaction (GC.compact) */ - objspace->flags.during_compacting = (!!((unsigned)reason & GPR_FLAG_COMPACT) << 1); + objspace->flags.during_compacting = !!(reason & GPR_FLAG_COMPACT); if (!heap_allocated_pages) return FALSE; /* heap is not ready */ if (!(reason & GPR_FLAG_METHOD) && !ready_to_gc(objspace)) return TRUE; /* GC is not allowed */ @@ -9472,11 +9452,7 @@ heap_check_moved_i(void *vstart, void *vend, size_t stride, void *data) https://github.com/ruby/ruby/blob/trunk/gc.c#L9452 static VALUE gc_compact(rb_execution_context_t *ec, VALUE self) { - /* Clear the heap. */ - gc_start_internal(ec, self, Qtrue, Qtrue, Qtrue, Qfalse); - - /* At this point, all references are live and the mutator is not allowed - * to run, so we don't need a read barrier. */ + /* Run GC with compaction enabled */ gc_start_internal(ec, self, Qtrue, Qtrue, Qtrue, Qtrue); return gc_compact_stats(ec, self); diff --git a/version.h b/version.h index b77710055f..55dcb6531a 100644 --- a/version.h +++ b/version.h @@ -12,7 +12,7 @@ https://github.com/ruby/ruby/blob/trunk/version.h#L12 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR #define RUBY_VERSION_TEENY 4 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR -#define RUBY_PATCHLEVEL 182 +#define RUBY_PATCHLEVEL 183 #define RUBY_RELEASE_YEAR 2022 #define RUBY_RELEASE_MONTH 3 -- cgit v1.2.1 -- ML: ruby-changes@q... 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