{"id":906,"date":"2017-08-03T08:12:35","date_gmt":"2017-08-03T12:12:35","guid":{"rendered":"https:\/\/www.devolve.net\/blog\/?p=906"},"modified":"2017-08-02T22:38:12","modified_gmt":"2017-08-03T02:38:12","slug":"kworker-using-cpu-on-an-otherwise-idle-system","status":"publish","type":"post","link":"https:\/\/www.devolve.local\/kworker-using-cpu-on-an-otherwise-idle-system\/","title":{"rendered":"kworker using cpu on an otherwise idle system"},"content":{"rendered":"<p>I have an old thin client that I upgraded to a home server by adding some additional RAM and storage. I noticed after a recent kernel upgrade that the system seemed sluggish at times, despite doing nothing in particular at the time. <code>top<\/code> showed that a kworker process was using CPU, not all of it, but perhaps 25 to 50% of the total CPU.<\/p>\n<p>I did a lot of searching to try and track down the offender. I used tools such as perf and iotop, read about various tunables under \/proc related to power management. Finally, I ran Intel&#8217;s powertop command. It showed that &#8220;Audio codec alsa&#8230;&#8221; was hammering on some event loop.<\/p>\n<p>I looked at the loaded kernel modules, and on a whim, I did <code>sudo rmmod snd_hda_intel<\/code> and that fixed the issue for me. <\/p>\n<p>Others may find that a kworker is running in a tight loop for some other reason. It could be some other misbehaving driver or an I\/O problem.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I have an old thin client that I upgraded to a home server by adding some additional RAM and storage. I noticed after a recent kernel upgrade that the system seemed sluggish at times, despite doing nothing in particular at the time. top showed that a kworker process was using CPU, not all of it, [&hellip;]<\/p>\n","protected":false},"author":3,"featured_media":910,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[6],"tags":[34,16,40,26],"_links":{"self":[{"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/posts\/906"}],"collection":[{"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/comments?post=906"}],"version-history":[{"count":2,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/posts\/906\/revisions"}],"predecessor-version":[{"id":911,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/posts\/906\/revisions\/911"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/media\/910"}],"wp:attachment":[{"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/media?parent=906"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/categories?post=906"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.devolve.local\/wp-json\/wp\/v2\/tags?post=906"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}