<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN"
"http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head><meta http-equiv="content-type" content="text/html; charset=utf-8" />
<title>[199454] releases/WebKitGTK/webkit-2.12/Source/bmalloc</title>
</head>
<body>
<style type="text/css"><!--
#msg dl.meta { border: 1px #006 solid; background: #369; padding: 6px; color: #fff; }
#msg dl.meta dt { float: left; width: 6em; font-weight: bold; }
#msg dt:after { content:':';}
#msg dl, #msg dt, #msg ul, #msg li, #header, #footer, #logmsg { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; }
#msg dl a { font-weight: bold}
#msg dl a:link { color:#fc3; }
#msg dl a:active { color:#ff0; }
#msg dl a:visited { color:#cc6; }
h3 { font-family: verdana,arial,helvetica,sans-serif; font-size: 10pt; font-weight: bold; }
#msg pre { overflow: auto; background: #ffc; border: 1px #fa0 solid; padding: 6px; }
#logmsg { background: #ffc; border: 1px #fa0 solid; padding: 1em 1em 0 1em; }
#logmsg p, #logmsg pre, #logmsg blockquote { margin: 0 0 1em 0; }
#logmsg p, #logmsg li, #logmsg dt, #logmsg dd { line-height: 14pt; }
#logmsg h1, #logmsg h2, #logmsg h3, #logmsg h4, #logmsg h5, #logmsg h6 { margin: .5em 0; }
#logmsg h1:first-child, #logmsg h2:first-child, #logmsg h3:first-child, #logmsg h4:first-child, #logmsg h5:first-child, #logmsg h6:first-child { margin-top: 0; }
#logmsg ul, #logmsg ol { padding: 0; list-style-position: inside; margin: 0 0 0 1em; }
#logmsg ul { text-indent: -1em; padding-left: 1em; }#logmsg ol { text-indent: -1.5em; padding-left: 1.5em; }
#logmsg > ul, #logmsg > ol { margin: 0 0 1em 0; }
#logmsg pre { background: #eee; padding: 1em; }
#logmsg blockquote { border: 1px solid #fa0; border-left-width: 10px; padding: 1em 1em 0 1em; background: white;}
#logmsg dl { margin: 0; }
#logmsg dt { font-weight: bold; }
#logmsg dd { margin: 0; padding: 0 0 0.5em 0; }
#logmsg dd:before { content:'\00bb';}
#logmsg table { border-spacing: 0px; border-collapse: collapse; border-top: 4px solid #fa0; border-bottom: 1px solid #fa0; background: #fff; }
#logmsg table th { text-align: left; font-weight: normal; padding: 0.2em 0.5em; border-top: 1px dotted #fa0; }
#logmsg table td { text-align: right; border-top: 1px dotted #fa0; padding: 0.2em 0.5em; }
#logmsg table thead th { text-align: center; border-bottom: 1px solid #fa0; }
#logmsg table th.Corner { text-align: left; }
#logmsg hr { border: none 0; border-top: 2px dashed #fa0; height: 1px; }
#header, #footer { color: #fff; background: #636; border: 1px #300 solid; padding: 6px; }
#patch { width: 100%; }
#patch h4 {font-family: verdana,arial,helvetica,sans-serif;font-size:10pt;padding:8px;background:#369;color:#fff;margin:0;}
#patch .propset h4, #patch .binary h4 {margin:0;}
#patch pre {padding:0;line-height:1.2em;margin:0;}
#patch .diff {width:100%;background:#eee;padding: 0 0 10px 0;overflow:auto;}
#patch .propset .diff, #patch .binary .diff {padding:10px 0;}
#patch span {display:block;padding:0 10px;}
#patch .modfile, #patch .addfile, #patch .delfile, #patch .propset, #patch .binary, #patch .copfile {border:1px solid #ccc;margin:10px 0;}
#patch ins {background:#dfd;text-decoration:none;display:block;padding:0 10px;}
#patch del {background:#fdd;text-decoration:none;display:block;padding:0 10px;}
#patch .lines, .info {color:#888;background:#fff;}
--></style>
<div id="msg">
<dl class="meta">
<dt>Revision</dt> <dd><a href="http://trac.webkit.org/projects/webkit/changeset/199454">199454</a></dd>
<dt>Author</dt> <dd>carlosgc@webkit.org</dd>
<dt>Date</dt> <dd>2016-04-13 02:39:38 -0700 (Wed, 13 Apr 2016)</dd>
</dl>
<h3>Log Message</h3>
<pre>Merge <a href="http://trac.webkit.org/projects/webkit/changeset/199246">r199246</a> - bmalloc: stress_aligned test fails if you increase smallMax
https://bugs.webkit.org/show_bug.cgi?id=156414
Reviewed by Oliver Hunt.
When size exceeds alignment and is a multiple of alignment and is not
a power of two, such as 24kB with 8kB alignment, the small allocator
did not always guarantee alignment. Let's fix that.
* bmalloc/Algorithm.h:
(bmalloc::divideRoundingUp): Math is hard.
* bmalloc/Allocator.cpp:
(bmalloc::Allocator::allocate): Align to the page size unconditionally.
Even if the page size is not a power of two, it might be a multiple of
a power of two, and we want alignment to that smaller power of two to
be guaranteed.</pre>
<h3>Modified Paths</h3>
<ul>
<li><a href="#releasesWebKitGTKwebkit212SourcebmallocChangeLog">releases/WebKitGTK/webkit-2.12/Source/bmalloc/ChangeLog</a></li>
<li><a href="#releasesWebKitGTKwebkit212SourcebmallocbmallocAlgorithmh">releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/Algorithm.h</a></li>
<li><a href="#releasesWebKitGTKwebkit212SourcebmallocbmallocVMHeapcpp">releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/VMHeap.cpp</a></li>
</ul>
</div>
<div id="patch">
<h3>Diff</h3>
<a id="releasesWebKitGTKwebkit212SourcebmallocChangeLog"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.12/Source/bmalloc/ChangeLog (199453 => 199454)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.12/Source/bmalloc/ChangeLog 2016-04-13 09:39:26 UTC (rev 199453)
+++ releases/WebKitGTK/webkit-2.12/Source/bmalloc/ChangeLog 2016-04-13 09:39:38 UTC (rev 199454)
</span><span class="lines">@@ -1,3 +1,23 @@
</span><ins>+2016-04-08 Geoffrey Garen <ggaren@apple.com>
+
+ bmalloc: stress_aligned test fails if you increase smallMax
+ https://bugs.webkit.org/show_bug.cgi?id=156414
+
+ Reviewed by Oliver Hunt.
+
+ When size exceeds alignment and is a multiple of alignment and is not
+ a power of two, such as 24kB with 8kB alignment, the small allocator
+ did not always guarantee alignment. Let's fix that.
+
+ * bmalloc/Algorithm.h:
+ (bmalloc::divideRoundingUp): Math is hard.
+
+ * bmalloc/Allocator.cpp:
+ (bmalloc::Allocator::allocate): Align to the page size unconditionally.
+ Even if the page size is not a power of two, it might be a multiple of
+ a power of two, and we want alignment to that smaller power of two to
+ be guaranteed.
+
</ins><span class="cx"> 2016-04-06 Geoffrey Garen <ggaren@apple.com>
</span><span class="cx">
</span><span class="cx"> bmalloc: handle aligned allocations on the fast path
</span></span></pre></div>
<a id="releasesWebKitGTKwebkit212SourcebmallocbmallocAlgorithmh"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/Algorithm.h (199453 => 199454)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/Algorithm.h 2016-04-13 09:39:26 UTC (rev 199453)
+++ releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/Algorithm.h 2016-04-13 09:39:38 UTC (rev 199454)
</span><span class="lines">@@ -87,7 +87,7 @@
</span><span class="cx"> return roundDownToMultipleOf(divisor, x);
</span><span class="cx"> }
</span><span class="cx">
</span><del>-template<typename T> void divideRoundingUp(T numerator, T denominator, T& quotient, T& remainder)
</del><ins>+template<typename T> inline void divideRoundingUp(T numerator, T denominator, T& quotient, T& remainder)
</ins><span class="cx"> {
</span><span class="cx"> // We expect the compiler to emit a single divide instruction to extract both the quotient and the remainder.
</span><span class="cx"> quotient = numerator / denominator;
</span><span class="lines">@@ -96,6 +96,11 @@
</span><span class="cx"> quotient += 1;
</span><span class="cx"> }
</span><span class="cx">
</span><ins>+template<typename T> inline T divideRoundingUp(T numerator, T denominator)
+{
+ return (numerator + denominator - 1) / denominator;
+}
+
</ins><span class="cx"> // Version of sizeof that returns 0 for empty classes.
</span><span class="cx">
</span><span class="cx"> template<typename T> inline constexpr size_t sizeOf()
</span></span></pre></div>
<a id="releasesWebKitGTKwebkit212SourcebmallocbmallocVMHeapcpp"></a>
<div class="modfile"><h4>Modified: releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/VMHeap.cpp (199453 => 199454)</h4>
<pre class="diff"><span>
<span class="info">--- releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/VMHeap.cpp 2016-04-13 09:39:26 UTC (rev 199453)
+++ releases/WebKitGTK/webkit-2.12/Source/bmalloc/bmalloc/VMHeap.cpp 2016-04-13 09:39:38 UTC (rev 199454)
</span><span class="lines">@@ -87,12 +87,9 @@
</span><span class="cx"> size_t pageSize = bmalloc::pageSize(pageClass);
</span><span class="cx"> size_t smallPageCount = pageSize / smallPageSize;
</span><span class="cx">
</span><del>- // If our page size is a power of two, we align to it in order to guarantee
- // that we can service aligned allocation requests at the same power of two.
- size_t alignment = vmPageSizePhysical();
- if (isPowerOfTwo(pageSize))
- alignment = pageSize;
- size_t metadataSize = roundUpToMultipleOf(alignment, sizeof(Chunk));
</del><ins>+ // We align to our page size in order to guarantee that we can service
+ // aligned allocation requests at equal and smaller powers of two.
+ size_t metadataSize = divideRoundingUp(sizeof(Chunk), pageSize) * pageSize;
</ins><span class="cx">
</span><span class="cx"> Object begin(chunk, metadataSize);
</span><span class="cx"> Object end(chunk, chunkSize);
</span></span></pre>
</div>
</div>
</body>
</html>