From 47f8caad4db06314d080b798f29b91e25dd51e76 Mon Sep 17 00:00:00 2001
From: daan <daanl@outlook.com>
Date: Sat, 5 Feb 2022 17:23:28 -0800
Subject: [PATCH] improve commit chunk alignment

---
 src/segment.c | 38 ++++++++++++++++++++++++++------------
 1 file changed, 26 insertions(+), 12 deletions(-)

diff --git a/src/segment.c b/src/segment.c
index 0970046d..b000e641 100644
--- a/src/segment.c
+++ b/src/segment.c
@@ -466,28 +466,35 @@ static void mi_segment_commit_mask(mi_segment_t* segment, bool conservative, uin
   mi_assert_internal(segment->kind != MI_SEGMENT_HUGE);
   mi_commit_mask_create_empty(cm);
   if (size == 0 || size > MI_SEGMENT_SIZE || segment->kind == MI_SEGMENT_HUGE) return;
+  const size_t segstart = mi_segment_info_size(segment);
   const size_t segsize = mi_segment_size(segment);
   if (p >= (uint8_t*)segment + segsize) return;
 
-  size_t diff = (p - (uint8_t*)segment);
-  mi_assert_internal(diff + size <= segsize);
+  size_t pstart = (p - (uint8_t*)segment);
+  mi_assert_internal(pstart + size <= segsize);
 
   size_t start;
   size_t end;
   if (conservative) {
     // decommit conservative
-    start = _mi_align_up(diff, MI_COMMIT_SIZE);
-    end   = _mi_align_down(diff + size, MI_COMMIT_SIZE);
+    start = _mi_align_up(pstart, MI_COMMIT_SIZE);
+    end   = _mi_align_down(pstart + size, MI_COMMIT_SIZE);
+    mi_assert_internal(start >= segstart);
+    mi_assert_internal(end <= segsize);
   }
   else {
     // commit liberal
-    start = _mi_align_down(diff, MI_COMMIT_SIZE);
-    end   = _mi_align_up(diff + size, MI_MINIMAL_COMMIT_SIZE);
+    start = _mi_align_down(pstart, MI_MINIMAL_COMMIT_SIZE);
+    end   = _mi_align_up(pstart + size, MI_MINIMAL_COMMIT_SIZE);
+  }
+  if (start < segstart) {
+    start = segstart;
   }
   if (end > segsize) {
     end = segsize;
   }
 
+  mi_assert_internal(start <= pstart && (pstart + size) <= end);
   mi_assert_internal(start % MI_COMMIT_SIZE==0 && end % MI_COMMIT_SIZE == 0);
   *start_p   = (uint8_t*)segment + start;
   *full_size = (end > start ? end - start : 0);
@@ -504,14 +511,19 @@ static void mi_segment_commit_mask(mi_segment_t* segment, bool conservative, uin
   mi_commit_mask_create(bitidx, bitcount, cm);
 }
 
-#define MI_COMMIT_SIZE_BATCH  MiB
 
 static bool mi_segment_commitx(mi_segment_t* segment, bool commit, uint8_t* p, size_t size, mi_stats_t* stats) {    
   mi_assert_internal(mi_commit_mask_all_set(&segment->commit_mask, &segment->decommit_mask));
 
-  //if (commit && size < MI_COMMIT_SIZE_BATCH && p + MI_COMMIT_SIZE_BATCH <= mi_segment_end(segment)) {
-  //  size = MI_COMMIT_SIZE_BATCH;
-  // }
+  // try to commit in at least MI_MINIMAL_COMMIT_SIZE sizes.
+  /*
+  if (commit && size > 0) {
+    const size_t csize = _mi_align_up(size, MI_MINIMAL_COMMIT_SIZE);
+    if (p + csize <= mi_segment_end(segment)) {
+      size = csize;
+    }
+  }
+  */
   // commit liberal, but decommit conservative
   uint8_t* start = NULL;
   size_t   full_size = 0;
@@ -569,13 +581,13 @@ static void mi_segment_perhaps_decommit(mi_segment_t* segment, uint8_t* p, size_
     if (mi_commit_mask_is_empty(&mask) || full_size==0) return;
     
     // update delayed commit
+    mi_assert_internal(segment->decommit_expire > 0 || mi_commit_mask_is_empty(&segment->decommit_mask));      
     mi_commit_mask_t cmask;
     mi_commit_mask_create_intersect(&segment->commit_mask, &mask, &cmask);  // only decommit what is committed; span_free may try to decommit more
     mi_commit_mask_set(&segment->decommit_mask, &cmask);
     mi_msecs_t now = _mi_clock_now();    
     if (segment->decommit_expire == 0) {
       // no previous decommits, initialize now
-      mi_assert_internal(mi_commit_mask_is_empty(&segment->decommit_mask));
       segment->decommit_expire = now + mi_option_get(mi_option_decommit_delay);
     }
     else if (segment->decommit_expire <= now) {
@@ -609,7 +621,8 @@ static void mi_segment_delayed_decommit(mi_segment_t* segment, bool force, mi_st
       mi_segment_commitx(segment, false, p, size, stats);
     }
   }
-  mi_commit_mask_foreach_end()  
+  mi_commit_mask_foreach_end()
+  mi_assert_internal(mi_commit_mask_is_empty(&segment->decommit_mask));
 }
 
 
@@ -893,6 +906,7 @@ static mi_segment_t* mi_segment_init(mi_segment_t* segment, size_t required, mi_
       mi_assert_internal(mi_commit_mask_is_empty(&decommit_mask));
       segment->decommit_expire = 0;
       mi_commit_mask_create_empty( &segment->decommit_mask );
+      mi_assert_internal(mi_commit_mask_is_empty(&segment->decommit_mask));
     }
   }