/*
- * sgen-cardtable.c: Card table implementation for sgen
+ * sgen-memory-governor.c: When to schedule collections based on
+ * memory usage.
*
* Author:
* Rodrigo Kumpera (rkumpera@novell.com)
*
- * SGen is licensed under the terms of the MIT X11 license
- *
* Copyright 2001-2003 Ximian, Inc
* Copyright 2003-2010 Novell, Inc.
* Copyright 2011 Xamarin Inc (http://www.xamarin.com)
- *
- * Permission is hereby granted, free of charge, to any person obtaining
- * a copy of this software and associated documentation files (the
- * "Software"), to deal in the Software without restriction, including
- * without limitation the rights to use, copy, modify, merge, publish,
- * distribute, sublicense, and/or sell copies of the Software, and to
- * permit persons to whom the Software is furnished to do so, subject to
- * the following conditions:
- *
- * The above copyright notice and this permission notice shall be
- * included in all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
- * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
- * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
- * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
- * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
- * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
- * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * Copyright (C) 2012 Xamarin Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License 2.0 as published by the Free Software Foundation;
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License 2.0 along with this library; if not, write to the Free
+ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "config.h"
#include "metadata/sgen-gc.h"
#include "metadata/sgen-memory-governor.h"
+#include "metadata/mono-gc.h"
+
+#include "utils/mono-counters.h"
+#include "utils/mono-mmap.h"
+#include "utils/mono-logger-internal.h"
+#include "utils/dtrace.h"
+
+#define MIN_MINOR_COLLECTION_ALLOWANCE ((mword)(DEFAULT_NURSERY_SIZE * default_allowance_nursery_size_ratio))
+
+/*Heap limits and allocation knobs*/
+static mword max_heap_size = ((mword)0)- ((mword)1);
+static mword soft_heap_limit = ((mword)0) - ((mword)1);
+
+static double default_allowance_nursery_size_ratio = SGEN_DEFAULT_ALLOWANCE_NURSERY_SIZE_RATIO;
+static double save_target_ratio = SGEN_DEFAULT_SAVE_TARGET_RATIO;
+
+/**/
+static mword allocated_heap;
+static mword total_alloc = 0;
+
+/* GC triggers. */
+
+static gboolean debug_print_allowance = FALSE;
+
+
+/* use this to tune when to do a major/minor collection */
+static mword memory_pressure = 0;
+static mword minor_collection_allowance;
+static int minor_collection_sections_alloced = 0;
+
+static int last_major_num_sections = 0;
+static int last_los_memory_usage = 0;
+
+static gboolean need_calculate_minor_collection_allowance;
+
+static int last_collection_old_num_major_sections;
+static mword last_collection_los_memory_usage = 0;
+static mword last_collection_old_los_memory_usage;
+static mword last_collection_los_memory_alloced;
+
+static mword sgen_memgov_available_free_space (void);
+
+
+static mword
+double_to_mword_with_saturation (double value)
+{
+ if (value >= (double)MWORD_MAX_VALUE)
+ return MWORD_MAX_VALUE;
+ return (mword)value;
+}
+
+/* GC trigger heuristics. */
+
+static void
+sgen_memgov_try_calculate_minor_collection_allowance (gboolean overwrite)
+{
+ int num_major_sections, num_major_sections_saved;
+ mword los_memory_saved, new_major, new_heap_size, save_target, allowance_target;
+
+ if (overwrite)
+ g_assert (need_calculate_minor_collection_allowance);
+
+ if (!need_calculate_minor_collection_allowance)
+ return;
+
+ if (!*major_collector.have_swept) {
+ if (overwrite)
+ minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
+ return;
+ }
+
+ num_major_sections = major_collector.get_num_major_sections ();
+
+ num_major_sections_saved = MAX (last_collection_old_num_major_sections - num_major_sections, 0);
+ los_memory_saved = MAX (last_collection_old_los_memory_usage - last_collection_los_memory_usage, 1);
+
+ new_major = num_major_sections * major_collector.section_size;
+ new_heap_size = new_major + last_collection_los_memory_usage;
+
+ save_target = (mword)((new_major + last_collection_los_memory_usage) * SGEN_DEFAULT_SAVE_TARGET_RATIO);
+
+ /*
+ * We aim to allow the allocation of as many sections as is
+ * necessary to reclaim save_target sections in the next
+ * collection. We assume the collection pattern won't change.
+ * In the last cycle, we had num_major_sections_saved for
+ * minor_collection_sections_alloced. Assuming things won't
+ * change, this must be the same ratio as save_target for
+ * allowance_target, i.e.
+ *
+ * num_major_sections_saved save_target
+ * --------------------------------- == ----------------
+ * minor_collection_sections_alloced allowance_target
+ *
+ * hence:
+ */
+ allowance_target = double_to_mword_with_saturation ((double)save_target * (double)(minor_collection_sections_alloced * major_collector.section_size + last_collection_los_memory_alloced) / (double)(num_major_sections_saved * major_collector.section_size + los_memory_saved));
+
+ minor_collection_allowance = MAX (MIN (allowance_target, num_major_sections * major_collector.section_size + los_memory_usage), MIN_MINOR_COLLECTION_ALLOWANCE);
+
+ if (new_heap_size + minor_collection_allowance > soft_heap_limit) {
+ if (new_heap_size > soft_heap_limit)
+ minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
+ else
+ minor_collection_allowance = MAX (soft_heap_limit - new_heap_size, MIN_MINOR_COLLECTION_ALLOWANCE);
+ }
+
+ if (debug_print_allowance) {
+ mword old_major = last_collection_old_num_major_sections * major_collector.section_size;
+
+ SGEN_LOG (1, "Before collection: %td bytes (%td major, %td LOS)",
+ old_major + last_collection_old_los_memory_usage, old_major, last_collection_old_los_memory_usage);
+ SGEN_LOG (1, "After collection: %td bytes (%td major, %td LOS)",
+ new_heap_size, new_major, last_collection_los_memory_usage);
+ SGEN_LOG (1, "Allowance: %td bytes", minor_collection_allowance);
+ }
+
+ if (major_collector.have_computed_minor_collection_allowance)
+ major_collector.have_computed_minor_collection_allowance ();
+
+ need_calculate_minor_collection_allowance = FALSE;
+}
+
+
+gboolean
+sgen_need_major_collection (mword space_needed)
+{
+ mword los_alloced;
+ if (sgen_concurrent_collection_in_progress ())
+ return FALSE;
+ los_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
+ return (space_needed > sgen_memgov_available_free_space ()) ||
+ minor_collection_sections_alloced * major_collector.section_size + los_alloced > minor_collection_allowance;
+}
+
+void
+sgen_memgov_minor_collection_start (void)
+{
+ sgen_memgov_try_calculate_minor_collection_allowance (FALSE);
+}
+
+void
+sgen_memgov_minor_collection_end (void)
+{
+}
+
+void
+sgen_memgov_major_collection_start (void)
+{
+ last_collection_old_num_major_sections = sgen_get_major_collector ()->get_num_major_sections ();
+
+ /*
+ * A domain could have been freed, resulting in
+ * los_memory_usage being less than last_collection_los_memory_usage.
+ */
+ last_collection_los_memory_alloced = los_memory_usage - MIN (last_collection_los_memory_usage, los_memory_usage);
+ last_collection_old_los_memory_usage = los_memory_usage;
+
+ need_calculate_minor_collection_allowance = TRUE;
+}
+
+void
+sgen_memgov_major_collection_end (void)
+{
+ sgen_memgov_try_calculate_minor_collection_allowance (TRUE);
+
+ minor_collection_sections_alloced = 0;
+ last_collection_los_memory_usage = los_memory_usage;
+}
+
+void
+sgen_memgov_collection_start (int generation)
+{
+ last_major_num_sections = major_collector.get_num_major_sections ();
+ last_los_memory_usage = los_memory_usage;
+}
+
+static void
+log_timming (GGTimingInfo *info)
+{
+ //unsigned long stw_time, unsigned long bridge_time, gboolean is_overflow
+ int num_major_sections = major_collector.get_num_major_sections ();
+ char full_timing_buff [1024];
+ full_timing_buff [0] = '\0';
+
+ if (!info->is_overflow)
+ sprintf (full_timing_buff, "total %.2fms, bridge %.2f", info->stw_time / 1000.0f, (int)info->bridge_time / 1000.0f);
+ if (info->generation == GENERATION_OLD)
+ mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MAJOR%s: (%s) pause %.2fms, %s major %dK/%dK los %dK/%dK",
+ info->is_overflow ? "_OVERFLOW" : "",
+ info->reason ? info->reason : "",
+ (int)info->total_time / 1000.0f,
+ full_timing_buff,
+ major_collector.section_size * num_major_sections / 1024,
+ major_collector.section_size * last_major_num_sections / 1024,
+ los_memory_usage / 1024,
+ last_los_memory_usage / 1024);
+ else
+ mono_trace (G_LOG_LEVEL_INFO, MONO_TRACE_GC, "GC_MINOR%s: (%s) pause %.2fms, %s promoted %dK major %dK los %dK",
+ info->is_overflow ? "_OVERFLOW" : "",
+ info->reason ? info->reason : "",
+ (int)info->total_time / 1000.0f,
+ full_timing_buff,
+ (num_major_sections - last_major_num_sections) * major_collector.section_size / 1024,
+ major_collector.section_size * num_major_sections / 1024,
+ los_memory_usage / 1024);
+}
+
+void
+sgen_memgov_collection_end (int generation, GGTimingInfo* info, int info_count)
+{
+ int i;
+ for (i = 0; i < info_count; ++i) {
+ if (info[i].generation != -1)
+ log_timming (&info [i]);
+ }
+}
+
+void
+sgen_register_major_sections_alloced (int num_sections)
+{
+ minor_collection_sections_alloced += num_sections;
+}
+
+mword
+sgen_get_minor_collection_allowance (void)
+{
+ return minor_collection_allowance;
+}
+
+/* Memory pressure API */
+
+/* Negative value to remove */
+void
+mono_gc_add_memory_pressure (gint64 value)
+{
+ /* FIXME: Use interlocked functions */
+ LOCK_GC;
+ memory_pressure += value;
+ UNLOCK_GC;
+}
+
+
+/*
+Global GC memory tracking.
+This tracks the total usage of memory by the GC. This includes
+managed and unmanaged memory.
+*/
+
+static unsigned long
+prot_flags_for_activate (int activate)
+{
+ unsigned long prot_flags = activate? MONO_MMAP_READ|MONO_MMAP_WRITE: MONO_MMAP_NONE;
+ return prot_flags | MONO_MMAP_PRIVATE | MONO_MMAP_ANON;
+}
+
+void
+sgen_assert_memory_alloc (void *ptr, size_t requested_size, const char *assert_description)
+{
+ if (ptr || !assert_description)
+ return;
+ fprintf (stderr, "Error: Garbage collector could not allocate %zu bytes of memory for %s.\n", requested_size, assert_description);
+ exit (1);
+}
+
+/*
+ * Allocate a big chunk of memory from the OS (usually 64KB to several megabytes).
+ * This must not require any lock.
+ */
+void*
+sgen_alloc_os_memory (size_t size, SgenAllocFlags flags, const char *assert_description)
+{
+ void *ptr;
+
+ g_assert (!(flags & ~(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE)));
+
+ ptr = mono_valloc (0, size, prot_flags_for_activate (flags & SGEN_ALLOC_ACTIVATE));
+ sgen_assert_memory_alloc (ptr, size, assert_description);
+ if (ptr) {
+ SGEN_ATOMIC_ADD_P (total_alloc, size);
+ if (flags & SGEN_ALLOC_HEAP)
+ MONO_GC_HEAP_ALLOC ((mword)ptr, size);
+ }
+ return ptr;
+}
+
+/* size must be a power of 2 */
+void*
+sgen_alloc_os_memory_aligned (size_t size, mword alignment, SgenAllocFlags flags, const char *assert_description)
+{
+ void *ptr;
+
+ g_assert (!(flags & ~(SGEN_ALLOC_HEAP | SGEN_ALLOC_ACTIVATE)));
+
+ ptr = mono_valloc_aligned (size, alignment, prot_flags_for_activate (flags & SGEN_ALLOC_ACTIVATE));
+ sgen_assert_memory_alloc (ptr, size, assert_description);
+ if (ptr) {
+ SGEN_ATOMIC_ADD_P (total_alloc, size);
+ if (flags & SGEN_ALLOC_HEAP)
+ MONO_GC_HEAP_ALLOC ((mword)ptr, size);
+ }
+ return ptr;
+}
+
+/*
+ * Free the memory returned by sgen_alloc_os_memory (), returning it to the OS.
+ */
+void
+sgen_free_os_memory (void *addr, size_t size, SgenAllocFlags flags)
+{
+ g_assert (!(flags & ~SGEN_ALLOC_HEAP));
+
+ mono_vfree (addr, size);
+ SGEN_ATOMIC_ADD_P (total_alloc, -size);
+ if (flags & SGEN_ALLOC_HEAP)
+ MONO_GC_HEAP_FREE ((mword)addr, size);
+}
+
+int64_t
+mono_gc_get_heap_size (void)
+{
+ return total_alloc;
+}
+
+
+/*
+Heap Sizing limits.
+This limit the max size of the heap. It takes into account
+only memory actively in use to hold heap objects and not
+for other parts of the GC.
+ */
+static mword
+sgen_memgov_available_free_space (void)
+{
+ return max_heap_size - MIN (allocated_heap, max_heap_size);
+}
+
+void
+sgen_memgov_release_space (mword size, int space)
+{
+ SGEN_ATOMIC_ADD_P (allocated_heap, -size);
+}
+
+gboolean
+sgen_memgov_try_alloc_space (mword size, int space)
+{
+ if (sgen_memgov_available_free_space () < size)
+ return FALSE;
+
+ SGEN_ATOMIC_ADD_P (allocated_heap, size);
+ mono_runtime_resource_check_limit (MONO_RESOURCE_GC_HEAP, allocated_heap);
+ return TRUE;
+}
+
+void
+sgen_memgov_init (glong max_heap, glong soft_limit, gboolean debug_allowance, double allowance_ratio, double save_target)
+{
+ if (soft_limit)
+ soft_heap_limit = soft_limit;
+
+ debug_print_allowance = debug_allowance;
+
+ if (max_heap == 0)
+ return;
+
+ if (max_heap < soft_limit) {
+ sgen_env_var_error (MONO_GC_PARAMS_NAME, "Setting to minimum.", "`max-heap-size` must be at least as large as `soft-heap-limit`.");
+ max_heap = soft_limit;
+ }
+
+ if (max_heap < sgen_nursery_size * 4) {
+ sgen_env_var_error (MONO_GC_PARAMS_NAME, "Setting to minimum.", "`max-heap-size` must be at least 4 times as large as `nursery size`.");
+ max_heap = sgen_nursery_size * 4;
+ }
+ max_heap_size = max_heap - sgen_nursery_size;
+
+ minor_collection_allowance = MIN_MINOR_COLLECTION_ALLOWANCE;
+
+ if (allowance_ratio)
+ default_allowance_nursery_size_ratio = allowance_ratio;
+
+ if (save_target)
+ save_target_ratio = save_target;
+}
#endif
projects / mono.git / blobdiff