X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Fgencgc.c;h=72e14592ecdf56675347a70c828d21181718ea6d;hb=344a1f088581303c92da333ddddc9aeb9c212ba9;hp=8c61a09b1014f45d2af59b4e7591f1e95e4ebd8d;hpb=b2bc5f9149d87e177830afb1104ea07e4ffe318e;p=sbcl.git diff --git a/src/runtime/gencgc.c b/src/runtime/gencgc.c index 8c61a09..72e1459 100644 --- a/src/runtime/gencgc.c +++ b/src/runtime/gencgc.c @@ -55,6 +55,9 @@ #if defined(LUTEX_WIDETAG) #include "pthread-lutex.h" #endif +#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) +#include "genesis/cons.h" +#endif /* forward declarations */ page_index_t gc_find_freeish_pages(long *restart_page_ptr, long nbytes, @@ -2214,8 +2217,6 @@ search_dynamic_space(void *pointer) (lispobj *)pointer)); } -#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) - /* Helper for valid_lisp_pointer_p and * possibly_valid_dynamic_space_pointer. * @@ -2304,6 +2305,23 @@ looks_like_valid_lisp_pointer_p(lispobj *pointer, lispobj *start_addr) } break; case OTHER_POINTER_LOWTAG: + +#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) + /* The all-architecture test below is good as far as it goes, + * but an LRA object is similar to a FUN-POINTER: It is + * embedded within a CODE-OBJECT pointed to by start_addr, and + * cannot be found by simply walking the heap, therefore we + * need to check for it. -- AB, 2010-Jun-04 */ + if ((widetag_of(start_addr[0]) == CODE_HEADER_WIDETAG)) { + lispobj *potential_lra = + (lispobj *)(((unsigned long)pointer) - OTHER_POINTER_LOWTAG); + if ((widetag_of(potential_lra[0]) == RETURN_PC_HEADER_WIDETAG) && + ((potential_lra - HeaderValue(potential_lra[0])) == start_addr)) { + return 1; /* It's as good as we can verify. */ + } + } +#endif + if ((unsigned long)pointer != ((unsigned long)start_addr+OTHER_POINTER_LOWTAG)) { if (gencgc_verbose) { @@ -2499,6 +2517,8 @@ valid_lisp_pointer_p(lispobj *pointer) return 0; } +#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) + /* Is there any possibility that pointer is a valid Lisp object * reference, and/or something else (e.g. subroutine call return * address) which should prevent us from moving the referred-to thing? @@ -2516,6 +2536,8 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer) return looks_like_valid_lisp_pointer_p(pointer, start_addr); } +#endif // defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) + /* Adjust large bignum and vector objects. This will adjust the * allocated region if the size has shrunk, and move unboxed objects * into unboxed pages. The pages are not promoted here, and the @@ -2734,11 +2756,17 @@ preserve_pointer(void *addr) * address referring to something in a CodeObject). This is * expensive but important, since it vastly reduces the * probability that random garbage will be bogusly interpreted as - * a pointer which prevents a page from moving. */ + * a pointer which prevents a page from moving. + * + * This only needs to happen on x86oids, where this is used for + * conservative roots. Non-x86oid systems only ever call this + * function on known-valid lisp objects. */ +#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) if (!(code_page_p(addr_page_index) || (is_lisp_pointer((lispobj)addr) && possibly_valid_dynamic_space_pointer(addr)))) return; +#endif /* Find the beginning of the region. Note that there may be * objects in the region preceding the one that we were passed a @@ -2817,9 +2845,6 @@ preserve_pointer(void *addr) /* Check that the page is now static. */ gc_assert(page_table[addr_page_index].dont_move != 0); } - -#endif // defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) - /* If the given page is not write-protected, then scan it for pointers * to younger generations or the top temp. generation, if no @@ -3805,165 +3830,19 @@ write_protect_generation_pages(generation_index_t generation) } #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64) - static void -scavenge_control_stack() +scavenge_control_stack(struct thread *th) { - unsigned long control_stack_size; - - /* This is going to be a big problem when we try to port threads - * to PPC... CLH */ - struct thread *th = arch_os_get_current_thread(); lispobj *control_stack = (lispobj *)(th->control_stack_start); + unsigned long control_stack_size = + access_control_stack_pointer(th) - control_stack; - control_stack_size = current_control_stack_pointer - control_stack; scavenge(control_stack, control_stack_size); } - -/* Scavenging Interrupt Contexts */ - -static int boxed_registers[] = BOXED_REGISTERS; - -static void -scavenge_interrupt_context(os_context_t * context) -{ - int i; - -#ifdef reg_LIP - unsigned long lip; - unsigned long lip_offset; - int lip_register_pair; -#endif - unsigned long pc_code_offset; - -#ifdef ARCH_HAS_LINK_REGISTER - unsigned long lr_code_offset; -#endif -#ifdef ARCH_HAS_NPC_REGISTER - unsigned long npc_code_offset; #endif -#ifdef reg_LIP - /* Find the LIP's register pair and calculate it's offset */ - /* before we scavenge the context. */ - - /* - * I (RLT) think this is trying to find the boxed register that is - * closest to the LIP address, without going past it. Usually, it's - * reg_CODE or reg_LRA. But sometimes, nothing can be found. - */ - lip = *os_context_register_addr(context, reg_LIP); - lip_offset = 0x7FFFFFFF; - lip_register_pair = -1; - for (i = 0; i < (sizeof(boxed_registers) / sizeof(int)); i++) { - unsigned long reg; - long offset; - int index; - - index = boxed_registers[i]; - reg = *os_context_register_addr(context, index); - if ((reg & ~((1L<uc_mcontext.gregs[2]. But gregs[2] is REG_nPC. Is - * that what we really want? My guess is that that is not what we - * want, so if lip_register_pair is -1, we don't touch reg_LIP at - * all. But maybe it doesn't really matter if LIP is trashed? - */ - if (lip_register_pair >= 0) { - *os_context_register_addr(context, reg_LIP) = - *os_context_register_addr(context, lip_register_pair) - + lip_offset; - } -#endif /* reg_LIP */ - - /* Fix the PC if it was in from space */ - if (from_space_p(*os_context_pc_addr(context))) - *os_context_pc_addr(context) = - *os_context_register_addr(context, reg_CODE) + pc_code_offset; - -#ifdef ARCH_HAS_LINK_REGISTER - /* Fix the LR ditto; important if we're being called from - * an assembly routine that expects to return using blr, otherwise - * harmless */ - if (from_space_p(*os_context_lr_addr(context))) - *os_context_lr_addr(context) = - *os_context_register_addr(context, reg_CODE) + lr_code_offset; -#endif - -#ifdef ARCH_HAS_NPC_REGISTER - if (from_space_p(*os_context_npc_addr(context))) - *os_context_npc_addr(context) = - *os_context_register_addr(context, reg_CODE) + npc_code_offset; -#endif /* ARCH_HAS_NPC_REGISTER */ -} - -void -scavenge_interrupt_contexts(void) -{ - int i, index; - os_context_t *context; - - struct thread *th=arch_os_get_current_thread(); - - index = fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,0)); - -#if defined(DEBUG_PRINT_CONTEXT_INDEX) - printf("Number of active contexts: %d\n", index); -#endif - - for (i = 0; i < index; i++) { - context = th->interrupt_contexts[i]; - scavenge_interrupt_context(context); - } -} - -#endif - -#if defined(LISP_FEATURE_SB_THREAD) +#if defined(LISP_FEATURE_SB_THREAD) && (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)) static void preserve_context_registers (os_context_t *c) { @@ -4014,9 +3893,8 @@ garbage_collect_generation(generation_index_t generation, int raise) unsigned long bytes_freed; page_index_t i; unsigned long static_space_size; -#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64) struct thread *th; -#endif + gc_assert(generation <= HIGHEST_NORMAL_GENERATION); /* The oldest generation can't be raised. */ @@ -4116,6 +3994,19 @@ garbage_collect_generation(generation_index_t generation, int raise) } } } +#else + /* Non-x86oid systems don't have "conservative roots" as such, but + * the same mechanism is used for objects pinned for use by alien + * code. */ + for_each_thread(th) { + lispobj pin_list = SymbolTlValue(PINNED_OBJECTS,th); + while (pin_list != NIL) { + struct cons *list_entry = + (struct cons *)native_pointer(pin_list); + preserve_pointer(list_entry->car); + pin_list = list_entry->cdr; + } + } #endif #if QSHOW @@ -4135,8 +4026,18 @@ garbage_collect_generation(generation_index_t generation, int raise) * If not x86, we need to scavenge the interrupt context(s) and the * control stack. */ - scavenge_interrupt_contexts(); - scavenge_control_stack(); + { + struct thread *th; + for_each_thread(th) { + scavenge_interrupt_contexts(th); + scavenge_control_stack(th); + } + + /* Scrub the unscavenged control stack space, so that we can't run + * into any stale pointers in a later GC (this is done by the + * stop-for-gc handler in the other threads). */ + scrub_control_stack(); + } #endif /* Scavenge the Lisp functions of the interrupt handlers, taking @@ -4586,6 +4487,10 @@ gc_init(void) page_table_pages = dynamic_space_size/PAGE_BYTES; gc_assert(dynamic_space_size == npage_bytes(page_table_pages)); + /* The page_table must be allocated using "calloc" to initialize + * the page structures correctly. There used to be a separate + * initialization loop (now commented out; see below) but that was + * unnecessary and did hurt startup time. */ page_table = calloc(page_table_pages, sizeof(struct page)); gc_assert(page_table); @@ -4601,14 +4506,38 @@ gc_init(void) heap_base = (void*)DYNAMIC_SPACE_START; - /* Initialize each page structure. */ - for (i = 0; i < page_table_pages; i++) { - /* Initialize all pages as free. */ - page_table[i].allocated = FREE_PAGE_FLAG; - page_table[i].bytes_used = 0; - - /* Pages are not write-protected at startup. */ - page_table[i].write_protected = 0; + /* The page structures are initialized implicitly when page_table + * is allocated with "calloc" above. Formerly we had the following + * explicit initialization here (comments converted to C99 style + * for readability as C's block comments don't nest): + * + * // Initialize each page structure. + * for (i = 0; i < page_table_pages; i++) { + * // Initialize all pages as free. + * page_table[i].allocated = FREE_PAGE_FLAG; + * page_table[i].bytes_used = 0; + * + * // Pages are not write-protected at startup. + * page_table[i].write_protected = 0; + * } + * + * Without this loop the image starts up much faster when dynamic + * space is large -- which it is on 64-bit platforms already by + * default -- and when "calloc" for large arrays is implemented + * using copy-on-write of a page of zeroes -- which it is at least + * on Linux. In this case the pages that page_table_pages is stored + * in are mapped and cleared not before the corresponding part of + * dynamic space is used. For example, this saves clearing 16 MB of + * memory at startup if the page size is 4 KB and the size of + * dynamic space is 4 GB. + * FREE_PAGE_FLAG must be 0 for this to work correctly which is + * asserted below: */ + { + /* Compile time assertion: If triggered, declares an array + * of dimension -1 forcing a syntax error. The intent of the + * assignment is to avoid an "unused variable" warning. */ + char assert_free_page_flag_0[(FREE_PAGE_FLAG) ? -1 : 1]; + assert_free_page_flag_0[0] = assert_free_page_flag_0[0]; } bytes_allocated = 0;