Drivers: hv: hv_balloon: eliminate jumps in piecewiese linear floor function

Commit 79208c57da53 ("Drivers: hv: hv_balloon: Make adjustments in computing
the floor") was inacurate as it introduced a jump in our piecewiese linear
'floor' function:

At 2048MB we have:
Left limit:
104 + 2048/8 = 360
Right limit:
256 + 2048/16 = 384 (so the right value is 232)

We now have to make an adjustment at 8192 boundary:
232 + 8192/16 = 744
512 + 8192/32 = 768 (so the right value is 488)

Suggested-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 99afef9393aa..4f5323cedab3 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -976,8 +976,8 @@ static unsigned long compute_balloon_floor(void)
          *     128        72    (1/2)
          *     512       168    (1/4)
          *    2048       360    (1/8)
-         *    8192       768    (1/16)
-         *   32768      1536    (1/32)
+         *    8192       744    (1/16)
+         *   32768      1512    (1/32)
          */
         if (totalram_pages < MB2PAGES(128))
                 min_pages = MB2PAGES(8) + (totalram_pages >> 1);
@@ -986,9 +986,9 @@ static unsigned long compute_balloon_floor(void)
         else if (totalram_pages < MB2PAGES(2048))
                 min_pages = MB2PAGES(104) + (totalram_pages >> 3);
         else if (totalram_pages < MB2PAGES(8192))
-                min_pages = MB2PAGES(256) + (totalram_pages >> 4);
+                min_pages = MB2PAGES(232) + (totalram_pages >> 4);
         else
-                min_pages = MB2PAGES(512) + (totalram_pages >> 5);
+                min_pages = MB2PAGES(488) + (totalram_pages >> 5);
 #undef MB2PAGES
         return min_pages;
 }