From f2436a6867b1b2fa60eefeb7a586f8ecd1a6e17e Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Wed, 11 Oct 2023 10:07:45 -0400
Subject: [PATCH 1/5] u3: revises free-list bounds

---
 pkg/noun/allocate.c | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/pkg/noun/allocate.c b/pkg/noun/allocate.c
index ace4473a4a..8cf2daaff9 100644
--- a/pkg/noun/allocate.c
+++ b/pkg/noun/allocate.c
@@ -76,27 +76,28 @@ _box_count(c3_ws siz_ws) { }
   } while(0)
 
 /* _box_slot(): select the right free list to search for a block.
-   TODO: do we really need a loop to do this?
-
-   so our free list logic looks like this:
-   siz_w < 6 words then [0]
-   siz_w < 16      then [1]
-   siz_w < 32      then [2]
-   siz_w < 64      then [3]
-   ...
-   siz_w > 4G      then [26]
+**
+**   siz_w ==  6 words then  [0]
+**   siz_w  < 16       then  [1]
+**   siz_w  < 32       then  [2]
+**   siz_w  < 64       then  [3]
+**   ...
+**   siz_w >=  2GB     then [26]
 */
 static c3_w
 _box_slot(c3_w siz_w)
 {
-  if ( siz_w < u3a_minimum ) {
-    return 0;
-  }
+  if ( u3a_minimum == siz_w ) return 0;
+
+  c3_dessert( u3a_minimum <= siz_w );
 
-  for (c3_w i_w = 1; i_w < u3a_fbox_no; i_w++) {
-    if ( siz_w < 16 ) return i_w;
-    siz_w = (siz_w + 1) >> 1;
+  {
+    c3_w bit_w = c3_bits_word(siz_w);
+
+    if ( 5 > bit_w ) return 1;
+    if ( (u3a_fbox_no + 1) >= bit_w ) return bit_w - 3;
   }
+
   return u3a_fbox_no - 1;
 }
 

From a1d23cee125b8408cb692786b0a10ceb610389d3 Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Wed, 11 Oct 2023 10:08:54 -0400
Subject: [PATCH 2/5] u3: adds free-list migration to account for new bounds

---
 pkg/noun/allocate.c | 63 +++++++++++++++++++++++++++++++++++++++++++++
 pkg/noun/allocate.h |  5 ++++
 pkg/noun/manage.c   |  4 +++
 3 files changed, 72 insertions(+)

diff --git a/pkg/noun/allocate.c b/pkg/noun/allocate.c
index 8cf2daaff9..a23c1231a2 100644
--- a/pkg/noun/allocate.c
+++ b/pkg/noun/allocate.c
@@ -2318,6 +2318,69 @@ u3a_idle(u3a_road* rod_u)
   return fre_w;
 }
 
+/* u3a_ream(): ream free-lists.
+*/
+void
+u3a_ream(void)
+{
+  u3p(u3a_fbox) lit_p;
+  u3a_fbox*     fox_u;
+  c3_w     sel_w, i_w;
+
+  for ( i_w = 0; i_w < u3a_fbox_no; i_w++ ) {
+    lit_p = u3R->all.fre_p[i_w];
+
+    while ( lit_p ) {
+      fox_u = u3to(u3a_fbox, lit_p);
+      lit_p = fox_u->nex_p;
+      sel_w = _box_slot(fox_u->box_u.siz_w);
+
+      if ( sel_w != i_w ) {
+        //  inlined _box_detach()
+        //
+        {
+          u3p(u3a_fbox) fre_p = u3of(u3a_fbox, &(fox_u->box_u));
+          u3p(u3a_fbox) pre_p = u3to(u3a_fbox, fre_p)->pre_p;
+          u3p(u3a_fbox) nex_p = u3to(u3a_fbox, fre_p)->nex_p;
+
+          if ( nex_p ) {
+            if ( u3to(u3a_fbox, nex_p)->pre_p != fre_p ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3to(u3a_fbox, nex_p)->pre_p = pre_p;
+          }
+          if ( pre_p ) {
+            if( u3to(u3a_fbox, pre_p)->nex_p != fre_p ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3to(u3a_fbox, pre_p)->nex_p = nex_p;
+          }
+          else {
+            if ( fre_p != u3R->all.fre_p[i_w] ) {
+              u3_assert(!"loom: corrupt");
+            }
+            u3R->all.fre_p[i_w] = nex_p;
+          }
+        }
+
+        //  inlined _box_attach()
+        {
+          u3p(u3a_fbox)  fre_p = u3of(u3a_fbox, &(fox_u->box_u));
+          u3p(u3a_fbox)* pfr_p = &u3R->all.fre_p[sel_w];
+          u3p(u3a_fbox)  nex_p = *pfr_p;
+
+          u3to(u3a_fbox, fre_p)->pre_p = 0;
+          u3to(u3a_fbox, fre_p)->nex_p = nex_p;
+          if ( nex_p ) {
+            u3to(u3a_fbox, nex_p)->pre_p = fre_p;
+          }
+          (*pfr_p) = fre_p;
+        }
+      }
+    }
+  }
+}
+
 /* u3a_sweep(): sweep a fully marked road.
 */
 c3_w
diff --git a/pkg/noun/allocate.h b/pkg/noun/allocate.h
index 7355954abd..c6fab95102 100644
--- a/pkg/noun/allocate.h
+++ b/pkg/noun/allocate.h
@@ -683,6 +683,11 @@
           c3_w
           u3a_idle(u3a_road* rod_u);
 
+        /* u3a_ream(): ream free-lists.
+        */
+          void
+          u3a_ream(void);
+
         /* u3a_sweep(): sweep a fully marked road.
         */
           c3_w
diff --git a/pkg/noun/manage.c b/pkg/noun/manage.c
index 5ff7d7b129..29833d001c 100644
--- a/pkg/noun/manage.c
+++ b/pkg/noun/manage.c
@@ -639,6 +639,10 @@ _find_home(void)
     }
   }
 
+  //  XX move me
+  //
+  u3a_ream();
+
   /* As a further guard against any sneaky loom corruption */
   u3a_loom_sane();
 

From 3553e43531eba85f7f8617152534000562dd7177 Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Wed, 11 Oct 2023 10:31:41 -0400
Subject: [PATCH 3/5] u3: use u3a_celloc() in u3a_take()

---
 pkg/noun/allocate.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/pkg/noun/allocate.c b/pkg/noun/allocate.c
index a23c1231a2..90f1b624fc 100644
--- a/pkg/noun/allocate.c
+++ b/pkg/noun/allocate.c
@@ -1123,9 +1123,7 @@ _ca_take_atom(u3a_atom* old_u)
 static inline u3_cell
 _ca_take_cell(u3a_cell* old_u, u3_noun hed, u3_noun tel)
 {
-  //  XX use u3a_celloc?
-  //
-  c3_w*     new_w = u3a_walloc(c3_wiseof(u3a_cell));
+  c3_w*     new_w = u3a_celloc();
   u3a_cell* new_u = (u3a_cell*)(void *)new_w;
   u3_cell     new = u3a_to_pom(u3a_outa(new_u));
 

From 2dc7d181de8b41d5989a5dbf424980645341904d Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Thu, 12 Oct 2023 21:50:58 -0400
Subject: [PATCH 4/5] u3: refactors _box_slot()

---
 pkg/noun/allocate.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/pkg/noun/allocate.c b/pkg/noun/allocate.c
index 90f1b624fc..ae022592c2 100644
--- a/pkg/noun/allocate.c
+++ b/pkg/noun/allocate.c
@@ -87,18 +87,18 @@ _box_count(c3_ws siz_ws) { }
 static c3_w
 _box_slot(c3_w siz_w)
 {
-  if ( u3a_minimum == siz_w ) return 0;
-
-  c3_dessert( u3a_minimum <= siz_w );
-
-  {
-    c3_w bit_w = c3_bits_word(siz_w);
-
-    if ( 5 > bit_w ) return 1;
-    if ( (u3a_fbox_no + 1) >= bit_w ) return bit_w - 3;
+  if ( u3a_minimum == siz_w ) {
+    return 0;
+  }
+  else if ( !(siz_w >> 4) ) {
+    c3_dessert( u3a_minimum < siz_w );
+    return 1;
+  }
+  else {
+    c3_w bit_w = c3_bits_word(siz_w) - 3;
+    c3_w max_w = u3a_fbox_no - 1;
+    return c3_min(bit_w, max_w);
   }
-
-  return u3a_fbox_no - 1;
 }
 
 /* _box_make(): construct a box.

From efe106650e8da7504b3aa3188875e9c7e06b2826 Mon Sep 17 00:00:00 2001
From: Joe Bryan <joemfb@gmail.com>
Date: Thu, 9 Nov 2023 15:42:34 -0500
Subject: [PATCH 5/5] u3: moves u3a_ream (free-list adjustment) into v3
 migration

---
 pkg/noun/manage.c      | 4 ----
 pkg/noun/v3/allocate.h | 1 +
 pkg/noun/v3/manage.c   | 3 +++
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/pkg/noun/manage.c b/pkg/noun/manage.c
index fde676b463..2de555d58c 100644
--- a/pkg/noun/manage.c
+++ b/pkg/noun/manage.c
@@ -652,10 +652,6 @@ _find_home(void)
     }
   }
 
-  //  XX move me
-  //
-  u3a_ream();
-
   /* As a further guard against any sneaky loom corruption */
   u3a_loom_sane();
 
diff --git a/pkg/noun/v3/allocate.h b/pkg/noun/v3/allocate.h
index bacc79e174..83db4a51b9 100644
--- a/pkg/noun/v3/allocate.h
+++ b/pkg/noun/v3/allocate.h
@@ -11,6 +11,7 @@
 #     define u3R_v3              u3a_Road
 #     define u3a_v3_balign       u3a_balign
 #     define u3a_v3_road         u3a_road
+#     define u3a_v3_ream         u3a_ream
 #     define u3a_v3_walign       u3a_walign
 #     define u3a_v3_walloc       u3a_walloc
 
diff --git a/pkg/noun/v3/manage.c b/pkg/noun/v3/manage.c
index a15d5ad9be..9eb8a96cdb 100644
--- a/pkg/noun/v3/manage.c
+++ b/pkg/noun/v3/manage.c
@@ -100,6 +100,9 @@ u3m_v3_migrate()
   u3R_v3 = &u3H_v3->rod_u;
   u3H_v3->ver_w = U3V_VER3;
 
+  //  recalculate free lists
+  u3a_v3_ream();
+
   //  initialize persistent cache
   u3R_v3->cax.per_p = u3h_v3_new_cache(u3C.per_w);