From: Cristy <urban-warrior@imagemagick.org>
Date: Tue, 4 Apr 2017 11:51:41 +0000 (-0400)
Subject: Align small memory allocations on the cache line
X-Git-Tag: 7.0.5-5~52
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e0a2d73c8d3717f4c414907807b81dc3f3f8c0b0;p=imagemagick

Align small memory allocations on the cache line
---

diff --git a/MagickCore/memory.c b/MagickCore/memory.c
index 318f7274f..985ab26a3 100644
--- a/MagickCore/memory.c
+++ b/MagickCore/memory.c
@@ -220,7 +220,7 @@ static MagickBooleanType
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  AcquireAlignedMemory() returns a pointer to a block of memory at least size
-%  bytes whose address is aligned on a page boundary.
+%  bytes whose address is aligned on a cache line or page boundary.
 %
 %  The format of the AcquireAlignedMemory method is:
 %
@@ -249,8 +249,10 @@ MagickExport void *AcquireAlignedMemory(const size_t count,const size_t quantum)
   if (HeapOverflowSanityCheck(count,quantum) != MagickFalse)
     return((void *) NULL);
   memory=NULL;
-  alignment=GetMagickPageSize();
   size=count*quantum;
+  alignment=CACHE_LINE_SIZE;
+  if (size > (GetMagickPageSize() >> 1))
+    alignment=GetMagickPageSize();
   extent=AlignedExtent(size,CACHE_LINE_SIZE);
   if ((size == 0) || (extent < size))
     return((void *) NULL);