* that don't have pointers to younger generations? */
boolean enable_page_protection = 1;
-/* Should we unmap a page and re-mmap it to have it zero filled? */
-#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__sun)
-/* comment from cmucl-2.4.8: This can waste a lot of swap on FreeBSD
- * so don't unmap there.
- *
- * The CMU CL comment didn't specify a version, but was probably an
- * old version of FreeBSD (pre-4.0), so this might no longer be true.
- * OTOH, if it is true, this behavior might exist on OpenBSD too, so
- * for now we don't unmap there either. -- WHN 2001-04-07 */
-/* Apparently this flag is required to be 0 for SunOS/x86, as there
- * are reports of heap corruption otherwise. */
-boolean gencgc_unmap_zero = 0;
-#else
-boolean gencgc_unmap_zero = 1;
-#endif
-
/* the minimum size (in bytes) for a large object*/
unsigned long large_object_size = 4 * PAGE_BYTES;
* contained a pagetable entry).
*/
boolean gencgc_partial_pickup = 0;
+
+/* If defined, free pages are read-protected to ensure that nothing
+ * accesses them.
+ */
+
+/* #define READ_PROTECT_FREE_PAGES */
+
\f
/*
* GC structures and variables
fpu_restore(fpu_state);
}
\f
-/*
- * allocation routines
+
+void fast_bzero(void*, size_t); /* in <arch>-assem.S */
+
+/* Zero the pages from START to END (inclusive), but use mmap/munmap instead
+ * if zeroing it ourselves, i.e. in practice give the memory back to the
+ * OS. Generally done after a large GC.
*/
+void zero_pages_with_mmap(page_index_t start, page_index_t end) {
+ int i;
+ void *addr = (void *) page_address(start), *new_addr;
+ size_t length = PAGE_BYTES*(1+end-start);
+
+ if (start > end)
+ return;
+
+ os_invalidate(addr, length);
+ new_addr = os_validate(addr, length);
+ if (new_addr == NULL || new_addr != addr) {
+ lose("remap_free_pages: page moved, 0x%08x ==> 0x%08x", start, new_addr);
+ }
+
+ for (i = start; i <= end; i++) {
+ page_table[i].need_to_zero = 0;
+ }
+}
+
+/* Zero the pages from START to END (inclusive). Generally done just after
+ * a new region has been allocated.
+ */
+static void
+zero_pages(page_index_t start, page_index_t end) {
+ if (start > end)
+ return;
+
+ fast_bzero(page_address(start), PAGE_BYTES*(1+end-start));
+}
+
+/* Zero the pages from START to END (inclusive), except for those
+ * pages that are known to already zeroed. Mark all pages in the
+ * ranges as non-zeroed.
+ */
+static void
+zero_dirty_pages(page_index_t start, page_index_t end) {
+ page_index_t i;
+
+ for (i = start; i <= end; i++) {
+ if (page_table[i].need_to_zero == 1) {
+ zero_pages(start, end);
+ break;
+ }
+ }
+
+ for (i = start; i <= end; i++) {
+ page_table[i].need_to_zero = 1;
+ }
+}
+
/*
* To support quick and inline allocation, regions of memory can be
* (long) in code like this, so that it is less likely to
* break randomly when running on a machine with different
* word sizes. -- WHN 19991129 */
- lose("The new region at %x is not zero.", p);
+ lose("The new region at %x is not zero.\n", p);
}
}
}
+
+#ifdef READ_PROTECT_FREE_PAGES
+ os_protect(page_address(first_page),
+ PAGE_BYTES*(1+last_page-first_page),
+ OS_VM_PROT_ALL);
+#endif
+
+ /* If the first page was only partial, don't check whether it's
+ * zeroed (it won't be) and don't zero it (since the parts that
+ * we're interested in are guaranteed to be zeroed).
+ */
+ if (page_table[first_page].bytes_used) {
+ first_page++;
+ }
+
+ zero_dirty_pages(first_page, last_page);
}
/* If the record_new_objects flag is 2 then all new regions created
}
thread_mutex_unlock(&free_pages_lock);
- return((void *)(page_address(first_page)+orig_first_page_bytes_used));
+#ifdef READ_PROTECT_FREE_PAGES
+ os_protect(page_address(first_page),
+ PAGE_BYTES*(1+last_page-first_page),
+ OS_VM_PROT_ALL);
+#endif
+
+ zero_dirty_pages(first_page, last_page);
+
+ return page_address(first_page);
}
static page_index_t gencgc_alloc_start_page = -1;
"Argh! gc_find_free_space failed (first_page), nbytes=%ld.\n",
nbytes);
print_generation_stats(1);
- lose(NULL);
+ lose("\n");
}
gc_assert(page_table[first_page].write_protected == 0);
"Argh! gc_find_freeish_pages failed (restart_page), nbytes=%ld.\n",
nbytes);
print_generation_stats(1);
- lose(NULL);
+ lose("\n");
}
*restart_page_ptr=first_page;
/* Scavenge element 0, which may be a hash-table structure. */
scavenge(where+2, 1);
if (!is_lisp_pointer(where[2])) {
- lose("no pointer at %x in hash table", where[2]);
+ lose("no pointer at %x in hash table\n", where[2]);
}
hash_table = (struct hash_table *)native_pointer(where[2]);
/*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
if (widetag_of(hash_table->header) != INSTANCE_HEADER_WIDETAG) {
- lose("hash table not instance (%x at %x)",
+ lose("hash table not instance (%x at %x)\n",
hash_table->header,
hash_table);
}
* the hash table code reserves for marking empty slots. */
scavenge(where+3, 1);
if (!is_lisp_pointer(where[3])) {
- lose("not empty-hash-table-slot symbol pointer: %x", where[3]);
+ lose("not empty-hash-table-slot symbol pointer: %x\n", where[3]);
}
empty_symbol = where[3];
/* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
if (widetag_of(*(lispobj *)native_pointer(empty_symbol)) !=
SYMBOL_HEADER_WIDETAG) {
- lose("not a symbol where empty-hash-table-slot symbol expected: %x",
+ lose("not a symbol where empty-hash-table-slot symbol expected: %x\n",
*(lispobj *)native_pointer(empty_symbol));
}
/* Cross-check the kv_vector. */
if (where != (lispobj *)native_pointer(hash_table->table)) {
- lose("hash_table table!=this table %x", hash_table->table);
+ lose("hash_table table!=this table %x\n", hash_table->table);
}
/* WEAK-P */
length = fixnum_value(((lispobj *)native_pointer(index_vector_obj))[1]);
/*FSHOW((stderr, "/length = %d\n", length));*/
} else {
- lose("invalid index_vector %x", index_vector_obj);
+ lose("invalid index_vector %x\n", index_vector_obj);
}
}
next_vector_length = fixnum_value(((lispobj *)native_pointer(next_vector_obj))[1]);
/*FSHOW((stderr, "/next_vector_length = %d\n", next_vector_length));*/
} else {
- lose("invalid next_vector %x", next_vector_obj);
+ lose("invalid next_vector %x\n", next_vector_obj);
}
}
num_wp += update_page_write_prot(j);
}
}
+ if ((gencgc_verbose > 1) && (num_wp != 0)) {
+ FSHOW((stderr,
+ "/write protected %d pages within generation %d\n",
+ num_wp, generation));
+ }
}
i = last_page;
}
}
- if ((gencgc_verbose > 1) && (num_wp != 0)) {
- FSHOW((stderr,
- "/write protected %d pages within generation %d\n",
- num_wp, generation));
- }
#if SC_GEN_CK
/* Check that none of the write_protected pages in this generation
page_table[i].bytes_used,
page_table[i].first_object_offset,
page_table[i].dont_move));
- lose("write to protected page %d in scavenge_generation()", i);
+ lose("write to protected page %d in scavenge_generation()\n", i);
}
}
#endif
&& (page_table[i].gen == generation)
&& (page_table[i].write_protected_cleared != 0)
&& (page_table[i].dont_move == 0)) {
- lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d",
+ lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d\n",
i, generation, page_table[i].dont_move);
}
}
&& (page_table[last_page].bytes_used != 0)
&& (page_table[last_page].gen == from_space));
- /* Zero pages from first_page to (last_page-1).
- *
- * FIXME: Why not use os_zero(..) function instead of
- * hand-coding this again? (Check other gencgc_unmap_zero
- * stuff too. */
- if (gencgc_unmap_zero) {
- void *page_start, *addr;
-
- page_start = (void *)page_address(first_page);
-
- os_invalidate(page_start, PAGE_BYTES*(last_page-first_page));
- addr = os_validate(page_start, PAGE_BYTES*(last_page-first_page));
- if (addr == NULL || addr != page_start) {
- lose("free_oldspace: page moved, 0x%08x ==> 0x%08x",page_start,
- addr);
- }
- } else {
- long *page_start;
-
- page_start = (long *)page_address(first_page);
- memset(page_start, 0,PAGE_BYTES*(last_page-first_page));
- }
-
+#ifdef READ_PROTECT_FREE_PAGES
+ os_protect(page_address(first_page),
+ PAGE_BYTES*(last_page-first_page),
+ OS_VM_PROT_NONE);
+#endif
first_page = last_page;
-
} while (first_page < last_free_page);
bytes_allocated -= bytes_freed;
* page. XX Could check the offset too. */
if ((page_table[page_index].allocated != FREE_PAGE_FLAG)
&& (page_table[page_index].bytes_used == 0))
- lose ("Ptr %x @ %x sees free page.", thing, start);
+ lose ("Ptr %x @ %x sees free page.\n", thing, start);
/* Check that it doesn't point to a forwarding pointer! */
if (*((lispobj *)native_pointer(thing)) == 0x01) {
- lose("Ptr %x @ %x sees forwarding ptr.", thing, start);
+ lose("Ptr %x @ %x sees forwarding ptr.\n", thing, start);
}
/* Check that its not in the RO space as it would then be a
* pointer from the RO to the dynamic space. */
if (is_in_readonly_space) {
- lose("ptr to dynamic space %x from RO space %x",
+ lose("ptr to dynamic space %x from RO space %x\n",
thing, start);
}
/* Does it point to a plausible object? This check slows
* dynamically. */
/*
if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
- lose("ptr %x to invalid object %x", thing, start);
+ lose("ptr %x to invalid object %x\n", thing, start);
}
*/
} else {
/* Verify that it points to another valid space. */
if (!to_readonly_space && !to_static_space
&& (thing != (unsigned long)&undefined_tramp)) {
- lose("Ptr %x @ %x sees junk.", thing, start);
+ lose("Ptr %x @ %x sees junk.\n", thing, start);
}
}
} else {
long i;
for (i = 0; i < size; i++) {
if (start_addr[i] != 0) {
- lose("free page not zero at %x", start_addr + i);
+ lose("free page not zero at %x\n", start_addr + i);
}
}
} else {
long i;
for (i = 0; i < size; i++) {
if (start_addr[i] != 0) {
- lose("free region not zero at %x", start_addr + i);
+ lose("free region not zero at %x\n", start_addr + i);
}
}
}
bytes_allocated = bytes_allocated - old_bytes_allocated;
if (bytes_allocated != 0) {
- lose("Rescan of new_space allocated %d more bytes.",
+ lose("Rescan of new_space allocated %d more bytes.\n",
bytes_allocated);
}
}
return 0; /* dummy value: return something ... */
}
+static void
+remap_free_pages (page_index_t from, page_index_t to)
+{
+ page_index_t first_page, last_page;
+
+ for (first_page = from; first_page <= to; first_page++) {
+ if (page_table[first_page].allocated != FREE_PAGE_FLAG ||
+ page_table[first_page].need_to_zero == 0) {
+ continue;
+ }
+
+ last_page = first_page + 1;
+ while (page_table[last_page].allocated == FREE_PAGE_FLAG &&
+ last_page < to &&
+ page_table[last_page].need_to_zero == 1) {
+ last_page++;
+ }
+
+ zero_pages_with_mmap(first_page, last_page-1);
+
+ first_page = last_page;
+ }
+}
+
+generation_index_t small_generation_limit = 1;
+
/* GC all generations newer than last_gen, raising the objects in each
* to the next older generation - we finish when all generations below
* last_gen are empty. Then if last_gen is due for a GC, or if
*
* We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
* last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
-
void
collect_garbage(generation_index_t last_gen)
{
generation_index_t gen = 0, i;
int raise;
int gen_to_wp;
+ /* The largest value of last_free_page seen since the time
+ * remap_free_pages was called. */
+ static page_index_t high_water_mark = 0;
FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
/* Check that they are all empty. */
for (i = 0; i < gen_to_wp; i++) {
if (generations[i].bytes_allocated)
- lose("trying to write-protect gen. %d when gen. %d nonempty",
+ lose("trying to write-protect gen. %d when gen. %d nonempty\n",
gen_to_wp, i);
}
write_protect_generation_pages(gen_to_wp);
gc_assert((boxed_region.free_pointer - boxed_region.start_addr) == 0);
gc_alloc_generation = 0;
+ /* Save the high-water mark before updating last_free_page */
+ if (last_free_page > high_water_mark)
+ high_water_mark = last_free_page;
update_dynamic_space_free_pointer();
auto_gc_trigger = bytes_allocated + bytes_consed_between_gcs;
if(gencgc_verbose)
fprintf(stderr,"Next gc when %ld bytes have been consed\n",
auto_gc_trigger);
+
+ /* If we did a big GC (arbitrarily defined as gen > 1), release memory
+ * back to the OS.
+ */
+ if (gen > small_generation_limit) {
+ if (last_free_page > high_water_mark)
+ high_water_mark = last_free_page;
+ remap_free_pages(0, high_water_mark);
+ high_water_mark = 0;
+ }
+
SHOW("returning from collect_garbage");
}
page_table[page].allocated = FREE_PAGE_FLAG;
page_table[page].bytes_used = 0;
+#ifndef LISP_FEATURE_WIN32 /* Pages already zeroed on win32? Not sure about this change. */
/* Zero the page. */
page_start = (void *)page_address(page);
os_invalidate(page_start,PAGE_BYTES);
addr = os_validate(page_start,PAGE_BYTES);
if (addr == NULL || addr != page_start) {
- lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x",
+ lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x\n",
page_start,
addr);
}
+#else
+ page_table[page].write_protected = 0;
+#endif
} else if (gencgc_zero_check_during_free_heap) {
/* Double-check that the page is zero filled. */
long *page_start;
page_start = (long *)page_address(page);
for (i=0; i<1024; i++) {
if (page_start[i] != 0) {
- lose("free region not zero at %x", page_start + i);
+ lose("free region not zero at %x\n", page_start + i);
}
}
}
page_table[page].write_protected = 0;
page_table[page].write_protected_cleared = 0;
page_table[page].dont_move = 0;
+ page_table[page].need_to_zero = 1;
if (!gencgc_partial_pickup) {
first=gc_search_space(prev,(ptr+2)-prev,ptr);
* does this test after the first one has already set wp=0
*/
if(page_table[page_index].write_protected_cleared != 1)
- lose("fault in heap page not marked as write-protected");
+ lose("fault in heap page not marked as write-protected\n");
}
/* Don't worry, we can handle it. */
return 1;
region->end_addr = page_address(0);
}
+static void
+zero_all_free_pages()
+{
+ page_index_t i;
+
+ for (i = 0; i < last_free_page; i++) {
+ if (page_table[i].allocated == FREE_PAGE_FLAG) {
+#ifdef READ_PROTECT_FREE_PAGES
+ os_protect(page_address(i),
+ PAGE_BYTES,
+ OS_VM_PROT_ALL);
+#endif
+ zero_pages(i, i);
+ }
+ }
+}
+
/* Things to do before doing a final GC before saving a core (without
* purify).
*
gencgc_alloc_start_page = -1;
collect_garbage(HIGHEST_NORMAL_GENERATION+1);
+ /* The dumper doesn't know that pages need to be zeroed before use. */
+ zero_all_free_pages();
save_to_filehandle(file, filename, SymbolValue(RESTART_LISP_FUNCTION,0));
/* Oops. Save still managed to fail. Since we've mangled the stack
* beyond hope, there's not much we can do.
* (beyond FUNCALLing RESTART_LISP_FUNCTION, but I suspect that's
* going to be rather unsatisfactory too... */
- lose("Attempt to save core after non-conservative GC failed.");
+ lose("Attempt to save core after non-conservative GC failed.\n");
}