1.1 --- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Thu Oct 21 17:29:24 2010 -0700
1.2 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Sat Oct 23 23:03:49 2010 -0700
1.3 @@ -354,12 +354,8 @@
1.4 double CMSStats::time_until_cms_gen_full() const {
1.5 size_t cms_free = _cms_gen->cmsSpace()->free();
1.6 GenCollectedHeap* gch = GenCollectedHeap::heap();
1.7 - size_t expected_promotion = gch->get_gen(0)->capacity();
1.8 - if (HandlePromotionFailure) {
1.9 - expected_promotion = MIN2(
1.10 - (size_t) _cms_gen->gc_stats()->avg_promoted()->padded_average(),
1.11 - expected_promotion);
1.12 - }
1.13 + size_t expected_promotion = MIN2(gch->get_gen(0)->capacity(),
1.14 + (size_t) _cms_gen->gc_stats()->avg_promoted()->padded_average());
1.15 if (cms_free > expected_promotion) {
1.16 // Start a cms collection if there isn't enough space to promote
1.17 // for the next minor collection. Use the padded average as
1.18 @@ -865,57 +861,18 @@
1.19 return free() + _virtual_space.uncommitted_size();
1.20 }
1.21
1.22 -bool ConcurrentMarkSweepGeneration::promotion_attempt_is_safe(
1.23 - size_t max_promotion_in_bytes,
1.24 - bool younger_handles_promotion_failure) const {
1.25 -
1.26 - // This is the most conservative test. Full promotion is
1.27 - // guaranteed if this is used. The multiplicative factor is to
1.28 - // account for the worst case "dilatation".
1.29 - double adjusted_max_promo_bytes = _dilatation_factor * max_promotion_in_bytes;
1.30 - if (adjusted_max_promo_bytes > (double)max_uintx) { // larger than size_t
1.31 - adjusted_max_promo_bytes = (double)max_uintx;
1.32 - }
1.33 - bool result = (max_contiguous_available() >= (size_t)adjusted_max_promo_bytes);
1.34 -
1.35 - if (younger_handles_promotion_failure && !result) {
1.36 - // Full promotion is not guaranteed because fragmentation
1.37 - // of the cms generation can prevent the full promotion.
1.38 - result = (max_available() >= (size_t)adjusted_max_promo_bytes);
1.39 -
1.40 - if (!result) {
1.41 - // With promotion failure handling the test for the ability
1.42 - // to support the promotion does not have to be guaranteed.
1.43 - // Use an average of the amount promoted.
1.44 - result = max_available() >= (size_t)
1.45 - gc_stats()->avg_promoted()->padded_average();
1.46 - if (PrintGC && Verbose && result) {
1.47 - gclog_or_tty->print_cr(
1.48 - "\nConcurrentMarkSweepGeneration::promotion_attempt_is_safe"
1.49 - " max_available: " SIZE_FORMAT
1.50 - " avg_promoted: " SIZE_FORMAT,
1.51 - max_available(), (size_t)
1.52 - gc_stats()->avg_promoted()->padded_average());
1.53 - }
1.54 - } else {
1.55 - if (PrintGC && Verbose) {
1.56 - gclog_or_tty->print_cr(
1.57 - "\nConcurrentMarkSweepGeneration::promotion_attempt_is_safe"
1.58 - " max_available: " SIZE_FORMAT
1.59 - " adj_max_promo_bytes: " SIZE_FORMAT,
1.60 - max_available(), (size_t)adjusted_max_promo_bytes);
1.61 - }
1.62 - }
1.63 - } else {
1.64 - if (PrintGC && Verbose) {
1.65 - gclog_or_tty->print_cr(
1.66 - "\nConcurrentMarkSweepGeneration::promotion_attempt_is_safe"
1.67 - " contiguous_available: " SIZE_FORMAT
1.68 - " adj_max_promo_bytes: " SIZE_FORMAT,
1.69 - max_contiguous_available(), (size_t)adjusted_max_promo_bytes);
1.70 - }
1.71 - }
1.72 - return result;
1.73 +bool ConcurrentMarkSweepGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
1.74 + size_t available = max_available();
1.75 + size_t av_promo = (size_t)gc_stats()->avg_promoted()->padded_average();
1.76 + bool res = (available >= av_promo) || (available >= max_promotion_in_bytes);
1.77 + if (PrintGC && Verbose) {
1.78 + gclog_or_tty->print_cr(
1.79 + "CMS: promo attempt is%s safe: available("SIZE_FORMAT") %s av_promo("SIZE_FORMAT"),"
1.80 + "max_promo("SIZE_FORMAT")",
1.81 + res? "":" not", available, res? ">=":"<",
1.82 + av_promo, max_promotion_in_bytes);
1.83 + }
1.84 + return res;
1.85 }
1.86
1.87 // At a promotion failure dump information on block layout in heap
1.88 @@ -6091,23 +6048,14 @@
1.89 assert(_collectorState == Resizing, "Change of collector state to"
1.90 " Resizing must be done under the freelistLocks (plural)");
1.91
1.92 - // Now that sweeping has been completed, if the GCH's
1.93 - // incremental_collection_will_fail flag is set, clear it,
1.94 + // Now that sweeping has been completed, we clear
1.95 + // the incremental_collection_failed flag,
1.96 // thus inviting a younger gen collection to promote into
1.97 // this generation. If such a promotion may still fail,
1.98 // the flag will be set again when a young collection is
1.99 // attempted.
1.100 - // I think the incremental_collection_will_fail flag's use
1.101 - // is specific to a 2 generation collection policy, so i'll
1.102 - // assert that that's the configuration we are operating within.
1.103 - // The use of the flag can and should be generalized appropriately
1.104 - // in the future to deal with a general n-generation system.
1.105 -
1.106 GenCollectedHeap* gch = GenCollectedHeap::heap();
1.107 - assert(gch->collector_policy()->is_two_generation_policy(),
1.108 - "Resetting of incremental_collection_will_fail flag"
1.109 - " may be incorrect otherwise");
1.110 - gch->clear_incremental_collection_will_fail();
1.111 + gch->clear_incremental_collection_failed(); // Worth retrying as fresh space may have been freed up
1.112 gch->update_full_collections_completed(_collection_count_start);
1.113 }
1.114
