diff options
Diffstat (limited to 'rts/sm/GC.c')
| -rw-r--r-- | rts/sm/GC.c | 51 |
1 files changed, 41 insertions, 10 deletions
diff --git a/rts/sm/GC.c b/rts/sm/GC.c index 695131e738..798a86c0ba 100644 --- a/rts/sm/GC.c +++ b/rts/sm/GC.c @@ -994,14 +994,40 @@ GarbageCollect (struct GcConfig config, commitMBlockFreeing(); if (major_gc) { - W_ need_prealloc, need_live, need, got; + W_ need_prealloc, need_copied_live, need_uncopied_live, need, got, extra_needed; uint32_t i; - need_live = 0; + need_copied_live = 0; + need_uncopied_live = 0; for (i = 0; i < RtsFlags.GcFlags.generations; i++) { - need_live += genLiveBlocks(&generations[i]); + need_copied_live += genLiveCopiedBlocks(&generations[i]); + need_uncopied_live += genLiveUncopiedBlocks(&generations[i]); } - need_live = stg_max(RtsFlags.GcFlags.minOldGenSize, need_live); + + debugTrace(DEBUG_gc, "(before) copied_live: %d; uncopied_live: %d", need_copied_live, need_uncopied_live ); + + + // minOldGenSize states that the size of the oldest generation must be at least + // as big as a certain value, so make sure to save enough memory for that. + extra_needed = 0; + if (RtsFlags.GcFlags.minOldGenSize >= need_copied_live + need_uncopied_live){ + extra_needed = RtsFlags.GcFlags.minOldGenSize - (need_copied_live + need_uncopied_live); + } + debugTrace(DEBUG_gc, "(minOldGen: %d; extra_needed: %d", RtsFlags.GcFlags.minOldGenSize, extra_needed); + + // If oldest gen is uncopying in some manner (compact or non-moving) then + // add the extra requested by minOldGenSize to uncopying portion of memory. + // Otherwise, the last generation is copying so add it to copying portion. + if (oldest_gen -> compact || RtsFlags.GcFlags.useNonmoving) { + need_uncopied_live += extra_needed; + } + else { + need_copied_live += extra_needed; + } + + ASSERT(need_uncopied_live + need_copied_live >= RtsFlags.GcFlags.minOldGenSize ); + + debugTrace(DEBUG_gc, "(after) copyied_live: %d; uncopied_live: %d", need_copied_live, need_uncopied_live ); need_prealloc = 0; for (i = 0; i < n_nurseries; i++) { @@ -1027,14 +1053,19 @@ GarbageCollect (struct GcConfig config, debugTrace(DEBUG_gc, "factors: %f %d %f", RtsFlags.GcFlags.oldGenFactor, consec_idle_gcs, scaled_factor ); - // Unavoidable need depends on GC strategy + // Unavoidable need for copying memory depends on GC strategy // * Copying need 2 * live // * Compacting need 1.x * live (we choose 1.2) - // * Nonmoving needs ~ 1.x * live - double unavoidable_need_factor = (oldest_gen->compact || RtsFlags.GcFlags.useNonmoving) - ? 1.2 : 2; - W_ scaled_needed = (scaled_factor + unavoidable_need_factor) * need_live; - debugTrace(DEBUG_gc, "factors_2: %f %d", unavoidable_need_factor, scaled_needed); + double unavoidable_copied_need_factor = (oldest_gen->compact) + ? 1.2 : 2; + + // Unmoving blocks (compacted, pinned, nonmoving GC blocks) are not going + // to be copied so don't need to save 2* the memory for them. + double unavoidable_uncopied_need_factor = 1.2; + + W_ scaled_needed = ((scaled_factor + unavoidable_copied_need_factor) * need_copied_live) + + ((scaled_factor + unavoidable_uncopied_need_factor) * need_uncopied_live); + debugTrace(DEBUG_gc, "factors_2: %f %d", ((scaled_factor + unavoidable_copied_need_factor) * need_copied_live), ((scaled_factor + unavoidable_uncopied_need_factor) * need_uncopied_live)); need = need_prealloc + scaled_needed; /* Also, if user set heap size, do not drop below it. |