Mercurial > hg
view tests/test-hgweb-removed.t @ 30212:260af19891f2
changegroup: increase write buffer size to 128k
By default, Python defers to the operating system for choosing the
default buffer size on opened files. On my Linux machine, the default
is 4k, which is really small for 2016.
This patch bumps the write buffer size when writing
changegroups/bundles to 128k. This matches the 128k read buffer
we already use on revlogs.
It's worth noting that this only impacts when writing to an explicit
file (such as during `hg bundle`). Buffers when writing to bundle
files via the repo vfs or to a temporary file are not impacted.
When producing a none-v2 bundle file of the mozilla-unified repository,
this change caused the number of write() system calls to drop from
952,449 to 29,788. After this change, the most frequent system
calls are fstat(), read(), lseek(), and open(). There were
2,523,672 system calls after this patch (so a net decrease of
~950k is statistically significant).
This change shows no performance change on my system. But I have a
high-end system with a fast SSD. It is quite possible this change
will have a significant impact on network file systems, where
extra network round trips due to excessive I/O system calls could
introduce significant latency.
| author | Gregory Szorc <gregory.szorc@gmail.com> |
|---|---|
| date | Sun, 16 Oct 2016 13:35:23 -0700 |
| parents | 4b0fc75f9403 |
| children | eb7de21b15be |
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#require serve setting up repo $ hg init test $ cd test $ echo a > a $ hg ci -Ama adding a $ hg rm a $ hg ci -mdel set up hgweb $ hg serve -n test -p $HGPORT -d --pid-file=hg.pid -A access.log -E errors.log $ cat hg.pid >> $DAEMON_PIDS revision $ get-with-headers.py localhost:$HGPORT 'rev/tip' 200 Script output follows <!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" xml:lang="en-US"> <head> <link rel="icon" href="/static/hgicon.png" type="image/png" /> <meta name="robots" content="index, nofollow" /> <link rel="stylesheet" href="/static/style-paper.css" type="text/css" /> <script type="text/javascript" src="/static/mercurial.js"></script> <title>test: c78f6c5cbea9</title> </head> <body> <div class="container"> <div class="menu"> <div class="logo"> <a href="https://mercurial-scm.org/"> <img src="/static/hglogo.png" alt="mercurial" /></a> </div> <ul> <li><a href="/shortlog/tip">log</a></li> <li><a href="/graph/tip">graph</a></li> <li><a href="/tags">tags</a></li> <li><a href="/bookmarks">bookmarks</a></li> <li><a href="/branches">branches</a></li> </ul> <ul> <li class="active">changeset</li> <li><a href="/raw-rev/tip">raw</a></li> <li><a href="/file/tip">browse</a></li> </ul> <ul> </ul> <ul> <li><a href="/help">help</a></li> </ul> </div> <div class="main"> <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2> <h3> changeset 1:<a href="/rev/c78f6c5cbea9">c78f6c5cbea9</a> <span class="tag">tip</span> </h3> <form class="search" action="/log"> <p><input name="rev" id="search1" type="text" size="30" /></p> <div id="hint">Find changesets by keywords (author, files, the commit message), revision number or hash, or <a href="/help/revsets">revset expression</a>.</div> </form> <div class="description">del</div> <table id="changesetEntry"> <tr> <th class="author">author</th> <td class="author">test</td> </tr> <tr> <th class="date">date</th> <td class="date age">Thu, 01 Jan 1970 00:00:00 +0000</td> </tr> <tr> <th class="author">parents</th> <td class="author"><a href="/rev/cb9a9f314b8b">cb9a9f314b8b</a> </td> </tr> <tr> <th class="author">children</th> <td class="author"></td> </tr> <tr> <th class="files">files</th> <td class="files">a </td> </tr> <tr> <th class="diffstat">diffstat</th> <td class="diffstat"> 1 files changed, 0 insertions(+), 1 deletions(-) <a id="diffstatexpand" href="javascript:toggleDiffstat()">[<tt>+</tt>]</a> <div id="diffstatdetails" style="display:none;"> <a href="javascript:toggleDiffstat()">[<tt>-</tt>]</a> <table class="diffstat-table stripes2"> <tr> <td class="diffstat-file"><a href="#l1.1">a</a></td> <td class="diffstat-total" align="right">1</td> <td class="diffstat-graph"> <span class="diffstat-add" style="width:0.0%;"> </span> <span class="diffstat-remove" style="width:100.0%;"> </span> </td> </tr> </table> </div> </td> </tr> </table> <div class="overflow"> <div class="sourcefirst linewraptoggle">line wrap: <a class="linewraplink" href="javascript:toggleLinewrap()">on</a></div> <div class="sourcefirst"> line diff</div> <div class="stripes2 diffblocks"> <div class="bottomline inc-lineno"><pre class="sourcelines wrap"> <span id="l1.1" class="minusline">--- a/a Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.1"></a> <span id="l1.2" class="plusline">+++ /dev/null Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.2"></a> <span id="l1.3" class="atline">@@ -1,1 +0,0 @@</span><a href="#l1.3"></a> <span id="l1.4" class="minusline">-a</span><a href="#l1.4"></a></pre></div> </div> </div> </div> </div> <script type="text/javascript">process_dates()</script> </body> </html> diff removed file $ get-with-headers.py localhost:$HGPORT 'diff/tip/a' 200 Script output follows <!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" xml:lang="en-US"> <head> <link rel="icon" href="/static/hgicon.png" type="image/png" /> <meta name="robots" content="index, nofollow" /> <link rel="stylesheet" href="/static/style-paper.css" type="text/css" /> <script type="text/javascript" src="/static/mercurial.js"></script> <title>test: a diff</title> </head> <body> <div class="container"> <div class="menu"> <div class="logo"> <a href="https://mercurial-scm.org/"> <img src="/static/hglogo.png" alt="mercurial" /></a> </div> <ul> <li><a href="/shortlog/tip">log</a></li> <li><a href="/graph/tip">graph</a></li> <li><a href="/tags">tags</a></li> <li><a href="/bookmarks">bookmarks</a></li> <li><a href="/branches">branches</a></li> </ul> <ul> <li><a href="/rev/tip">changeset</a></li> <li><a href="/file/tip">browse</a></li> </ul> <ul> <li><a href="/file/tip/a">file</a></li> <li><a href="/file/tip/a">latest</a></li> <li class="active">diff</li> <li><a href="/comparison/tip/a">comparison</a></li> <li><a href="/annotate/tip/a">annotate</a></li> <li><a href="/log/tip/a">file log</a></li> <li><a href="/raw-file/tip/a">raw</a></li> </ul> <ul> <li><a href="/help">help</a></li> </ul> </div> <div class="main"> <h2 class="breadcrumb"><a href="/">Mercurial</a> </h2> <h3> diff a @ 1:<a href="/rev/c78f6c5cbea9">c78f6c5cbea9</a> <span class="tag">tip</span> </h3> <form class="search" action="/log"> <p></p> <p><input name="rev" id="search1" type="text" size="30" /></p> <div id="hint">Find changesets by keywords (author, files, the commit message), revision number or hash, or <a href="/help/revsets">revset expression</a>.</div> </form> <div class="description">del</div> <table id="changesetEntry"> <tr> <th>author</th> <td>test</td> </tr> <tr> <th>date</th> <td class="date age">Thu, 01 Jan 1970 00:00:00 +0000</td> </tr> <tr> <th>parents</th> <td><a href="/file/cb9a9f314b8b/a">cb9a9f314b8b</a> </td> </tr> <tr> <th>children</th> <td></td> </tr> </table> <div class="overflow"> <div class="sourcefirst linewraptoggle">line wrap: <a class="linewraplink" href="javascript:toggleLinewrap()">on</a></div> <div class="sourcefirst"> line diff</div> <div class="stripes2 diffblocks"> <div class="bottomline inc-lineno"><pre class="sourcelines wrap"> <span id="l1.1" class="minusline">--- a/a Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.1"></a> <span id="l1.2" class="plusline">+++ /dev/null Thu Jan 01 00:00:00 1970 +0000</span><a href="#l1.2"></a> <span id="l1.3" class="atline">@@ -1,1 +0,0 @@</span><a href="#l1.3"></a> <span id="l1.4" class="minusline">-a</span><a href="#l1.4"></a></pre></div> </div> </div> </div> </div> <script type="text/javascript">process_dates()</script> </body> </html> $ cd ..