Scale AG count and AG size appropriately below 128MB

Merge of master-melb:xfs-cmds:30601a by kenmcd.

  Scale AG count and AG size appropriately below 128MB

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 1913b95358746842a200bc03cd07cbc9685bcf00..1251f36dc665028a4a5bb50c1ea43a05bc143c9b 100644 (file)
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -406,31 +406,20 @@ calc_default_ag_geometry(
        __uint64_t      *agcount)
 {
        __uint64_t      blocks = 0;
-       __uint64_t      count = 0;
        int             shift = 0;
 
        /*
-        * First handle the extremes - the points at which we will
-        * always use the maximum AG size, the points at which we
-        * always use the minimum, and a "small-step" for 16-128MB.
+        * First handle the high extreme - the point at which we will
+        * always use the maximum AG size.
         *
-        * These apply regardless of storage configuration.
+        * This applies regardless of storage configuration.
         */
        if (dblocks >= TERABYTES(32, blocklog)) {
                blocks = XFS_AG_MAX_BLOCKS(blocklog);
                goto done;
-       } else if (dblocks < MEGABYTES(16, blocklog)) {
-               blocks = dblocks;
-               count = 1;
-               goto done;
-       } else if (dblocks < MEGABYTES(128, blocklog)) {
-               blocks = MEGABYTES(16, blocklog);
-               goto done;
        }
 
        /*
-        * Sizes between 128MB and 32TB:
-        *
         * For the remainder we choose an AG size based on the
         * number of data blocks available, trying to keep the
         * number of AGs relatively small (especially compared
@@ -439,25 +428,29 @@ calc_default_ag_geometry(
         * count can be increased by growfs, so prefer to use
         * smaller counts at mkfs time.
         *
-        * For a single underlying storage device less than 4TB
-        * in size, just use 4 AGs, otherwise (for JBOD/RAIDs)
-        * scale up smoothly between min/max AG sizes.
+        * For a single underlying storage device between 128MB
+        * and 4TB in size, just use 4 AGs, otherwise scale up
+        * smoothly between min/max AG sizes.
         */
 
-       if (!multidisk) {
+       if (!multidisk && dblocks >= MEGABYTES(128, blocklog)) {
                if (dblocks >= TERABYTES(4, blocklog)) {
-                        blocks = XFS_AG_MAX_BLOCKS(blocklog);
-                        goto done;
-                }
-                shift = 2;
-        } else if (dblocks > GIGABYTES(512, blocklog))
+                       blocks = XFS_AG_MAX_BLOCKS(blocklog);
+                       goto done;
+               }
+               shift = 2;
+       } else if (dblocks > GIGABYTES(512, blocklog))
                shift = 5;
        else if (dblocks > GIGABYTES(8, blocklog))
                shift = 4;
        else if (dblocks >= MEGABYTES(128, blocklog))
                shift = 3;
+       else if (dblocks >= MEGABYTES(64, blocklog))
+               shift = 2;
+       else if (dblocks >= MEGABYTES(32, blocklog))
+               shift = 1;
        else
-               ASSERT(0);
+               shift = 0;
        /*
         * If dblocks is not evenly divisible by the number of
         * desired AGs, round "blocks" up so we don't lose the
@@ -467,11 +460,8 @@ calc_default_ag_geometry(
        blocks = (dblocks >> shift) + ((dblocks & xfs_mask32lo(shift)) != 0);
 
 done:
-       if (!count)
-               count = dblocks / blocks + (dblocks % blocks != 0);
-
        *agsize = blocks;
-       *agcount = count;
+       *agcount = dblocks / blocks + (dblocks % blocks != 0);
 }
 
 static void