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<a href=/index.xml target=_blank class=hob>RSS</a></nav></header><main role=main><article itemtype=http://schema.org/Article><h1 itemtype=headline>Golang profiling simplified</h1><p><cap>post</cap>, Mar 7, 2017 on <a href=https://mitjafelicijan.com>Mitja Felicijan's blog</a><div><p>Many posts have been written regarding profiling in Golang and I haven’t found
proper tutorial regarding this. Almost all of them are missing some part of
important information and it gets pretty frustrating when you have a deadline
and are not finding simple distilled solution.<p>Nevertheless, after searching and experimenting I have found a solution that
works for me and probably should also for you.<h2 id=where-are-my-pprof-files>Where are my pprof files?</h2><p>By default pprof files are generated in /tmp/ folder. You can override folder
where this files are generated programmatically in your golang code as we will
see below in example.<h2 id=why-is-my-cpu-profile-empty>Why is my CPU profile empty?</h2><p>I have found out that sometimes CPU profile is empty because program was not
executing long enough. Programs, that execute too quickly don’t produce pprof
file in my cases. Well, file is generated but only contains 4KB of information.<h2 id=profiling>Profiling</h2><p>As you can see from examples we are executing dummy_benchmark functions to
ensure some sort of execution. Memory profiling can be done without such a
“complex” function. But CPU profiling needs it.<p>Both memory and CPU profiling examples are almost the same. Only parameters in
main function when calling profile.Start are different. When we set
profile.ProfilePath(“.”) we tell profiler to store pprof files in the same
folder as our program.<h3 id=memory-profiling>Memory profiling</h3><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:#00f>package</span> main
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>import</span> (
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;fmt&#34;</span>
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;time&#34;</span>
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;github.com/pkg/profile&#34;</span>
</span></span><span style=display:flex><span>)
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>func</span> dummy_benchmark() {
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  fmt.Println(<span style=color:#a31515>&#34;first set ...&#34;</span>)
</span></span><span style=display:flex><span>  <span style=color:#00f>for</span> i := 0; i &lt; 918231333; i++ {
</span></span><span style=display:flex><span>    i *= 2
</span></span><span style=display:flex><span>    i /= 2
</span></span><span style=display:flex><span>  }
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  &lt;-time.After(time.Second*3)
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  fmt.Println(<span style=color:#a31515>&#34;sencond set ...&#34;</span>)
</span></span><span style=display:flex><span>  <span style=color:#00f>for</span> i := 0; i &lt; 9182312232; i++ {
</span></span><span style=display:flex><span>    i *= 2
</span></span><span style=display:flex><span>    i /= 2
</span></span><span style=display:flex><span>  }
</span></span><span style=display:flex><span>}
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>func</span> main() {
</span></span><span style=display:flex><span>  <span style=color:#00f>defer</span> profile.Start(profile.MemProfile, profile.ProfilePath(<span style=color:#a31515>&#34;.&#34;</span>), profile.NoShutdownHook).Stop()
</span></span><span style=display:flex><span>  dummy_benchmark()
</span></span><span style=display:flex><span>}
</span></span></code></pre><h3 id=cpu-profiling>CPU profiling</h3><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:#00f>package</span> main
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>import</span> (
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;fmt&#34;</span>
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;time&#34;</span>
</span></span><span style=display:flex><span>  <span style=color:#a31515>&#34;github.com/pkg/profile&#34;</span>
</span></span><span style=display:flex><span>)
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>func</span> dummy_benchmark() {
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  fmt.Println(<span style=color:#a31515>&#34;first set ...&#34;</span>)
</span></span><span style=display:flex><span>  <span style=color:#00f>for</span> i := 0; i &lt; 918231333; i++ {
</span></span><span style=display:flex><span>    i *= 2
</span></span><span style=display:flex><span>    i /= 2
</span></span><span style=display:flex><span>  }
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  &lt;-time.After(time.Second*3)
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span>  fmt.Println(<span style=color:#a31515>&#34;sencond set ...&#34;</span>)
</span></span><span style=display:flex><span>  <span style=color:#00f>for</span> i := 0; i &lt; 9182312232; i++ {
</span></span><span style=display:flex><span>    i *= 2
</span></span><span style=display:flex><span>    i /= 2
</span></span><span style=display:flex><span>  }
</span></span><span style=display:flex><span>}
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:#00f>func</span> main() {
</span></span><span style=display:flex><span>  <span style=color:#00f>defer</span> profile.Start(profile.CPUProfile, profile.ProfilePath(<span style=color:#a31515>&#34;.&#34;</span>), profile.NoShutdownHook).Stop()
</span></span><span style=display:flex><span>  dummy_benchmark()
</span></span><span style=display:flex><span>}
</span></span></code></pre><h3 id=generating-profiling-reports>Generating profiling reports</h3><pre tabindex=0 style=background-color:#fff><code><span style=display:flex><span><span style=color:green># memory profiling</span>
</span></span><span style=display:flex><span>go build mem.go
</span></span><span style=display:flex><span>./mem
</span></span><span style=display:flex><span>go tool pprof -pdf ./mem mem.pprof &gt; mem.pdf
</span></span><span style=display:flex><span>
</span></span><span style=display:flex><span><span style=color:green># cpu profiling</span>
</span></span><span style=display:flex><span>go build cpu.go
</span></span><span style=display:flex><span>./cpu
</span></span><span style=display:flex><span>go tool pprof -pdf ./cpu cpu.pprof &gt; cpu.pdf
</span></span></code></pre><p>This will generate PDF document with visualized profile.<ul><li><a href=/posts/go-profiling/golang-profiling-mem.pdf>Memory PDF profile example</a><li><a href=/posts/go-profiling/golang-profiling-cpu.pdf>CPU PDF profile example</a></ul></div></article></main><section><hr><h2>Posts from blogs I follow around the net</h2><ul><li><a href=https://utcc.utoronto.ca/~cks/space/blog/solaris/ZFSWhyNotDirectoryToFilesystem target=_blank rel=noopener>One reason that ZFS can't turn a directory into a filesystem</a> — <a href=https://utcc.utoronto.ca/~cks/space/blog/>Chris's Wiki :: blog</a><div>One of the wishes that I and other people frequently have for ZFS
is the ability to take an existing directory (and everything
underneath it) in a ZFS filesystem and turn it into a sub-filesystem
of its own. One reason for wanting this is that a number of things
are set and controlled on a per-filesyst…<li><a href=http://www.landley.net/notes-2023.html#28-10-2023 target=_blank rel=noopener>October 28, 2023</a> — <a href=http://www.landley.net/notes-2023.html>Rob Landley's Blog Thing for 2023</a><div>Oh good grief, two of my least favorite licensing people, Larry Rosen
and Bradley Kuhn, are interacting on the OSI's license-discuss
list where the're doing
bad computer history and insisting that a guy Larry Rosen
coincidentally interviewed for a book years ago is clearly the origin of
somethin…<li><a href="http://offbeatpursuit.com:80/blog/?id=25" target=_blank rel=noopener>A fix by any other name</a> — <a href=http://offbeatpursuit.com:80/blog/>WLOG - blog</a><div>tags:
i2c, plan9
Another month, another file system.
Well, if you can’t fix it in software, fix it in hardware (looking at
you, bme680, we’re not
done yet). The show must go on, as they say, and I would like my
experiments to go on.
So a “new” addition to the environmental sensor family connected to
the h…<li><a href=https://mirzapandzo.com/next-image-url-parameter-is-valid-but-upstream-response-is-invalid target=_blank rel=noopener>Next/Image "url" parameter is valid but upstream response is invalid</a> — <a href=https://mirzapandzo.com/>Mirza Pandzo's Blog</a><div>Getting "url" parameter is valid but upstream response is invalid error with Next/Image on WSL2<li><a href=https://drewdevault.com/2023/10/13/Going-off-script.html target=_blank rel=noopener>Going off-script</a> — <a href=https://drewdevault.com>Drew DeVault's blog</a><div>There is a phenomenon in society which I find quite bizarre. Upon our entry to
this mortal coil, we are endowed with self-awareness, agency, and free will.
Each of the 8 billion members of this human race represents a unique person, a
unique worldview, and a unique agency. Yet, many of us have the sam…<li><a href=https://szymonkaliski.com/writing/2023-10-02-building-a-diy-pen-plotter/ target=_blank rel=noopener>Building a DIY Pen Plotter</a> — <a href=http://github.com/dylang/node-rss>Szymon Kaliski</a><div>This article documents my learnings from designing and building a DIY Pen Plotter during the summer of 2023.
My ultimate goal is to build my…<li><a href=https://neil.computer/notes/chart-of-accounts-for-startups-and-saas-companies/ target=_blank rel=noopener>Chart of Accounts for Startups and SaaS Companies</a> — <a href=https://neil.computer/>Neil Panchal</a><div>Accounting is fundamental to starting a business. You need to have a basic understanding of accounting principles and essential bookkeeping. I had to learn it. There was no choice. For filing taxes, your CPA is going to ask you for an Income Statement (also known as P/L statement). If<li><a href=https://journal.valeriansaliou.name/deploy-a-nomad-cluster-on-alpine-linux-with-vultr/ target=_blank rel=noopener>Deploy a Nomad Cluster on Alpine Linux with Vultr</a> — <a href=https://journal.valeriansaliou.name/>Valerian Saliou</a><div>After spending countless hours trying to understand how to deploy my apps on Kubernetes for the first time to host Mirage, an AI API service that I run, I ended up making myself a promise that the next app I work on would be using a more productive & simpler<li><a href=https://jcs.org/2023/10/25/wifi_da target=_blank rel=noopener>BlueSCSI Wi-Fi Desk Accessory 1.0 Released</a> — <a href=https://jcs.org/>joshua stein</a><div>BlueSCSI Wi-Fi Desk Accessory
1.0 has been released:
wifi_da-1.0.sit
(StuffIt 3 archive)
SHA256: ccfc9d27dd5da7412d10cef73b81119a1fec3848e4d1d88ff652a07ffdc6a69aSHA1: ff124972f202ceda6d7fa4788110a67ccda6a13a
This is the initial public release of my BlueSCSI Wi-Fi Desk Accessory for
classic MacOS.<li><a href=https://michael.stapelberg.ch/posts/2023-10-25-my-all-flash-zfs-network-storage-build/ target=_blank rel=noopener>My 2023 all-flash ZFS NAS (Network Storage) build</a> — <a href=https://michael.stapelberg.ch/>Michael Stapelbergs Website</a><div>For over 10 years now, I run two self-built NAS (Network Storage) devices which serve media (currently via Jellyfin) and run daily backups of all my PCs and servers.
In this article, I describe my goals, which hardware I picked for my new build (and why) and how I set it up.
Design Goals
I use my netw…</ul><p>Generated with <a href=https://git.sr.ht/~sircmpwn/openring target=_blank rel=noopener>openring</a>.</section><footer><hr><p><big><strong>Want to comment or have something to add?</strong></big><p>You can write me an email
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