{"id":2951,"date":"2014-07-15T10:28:54","date_gmt":"2014-07-14T23:28:54","guid":{"rendered":"http:\/\/blog.mozilla.org\/nnethercote\/?p=2951"},"modified":"2014-07-15T10:28:54","modified_gmt":"2014-07-14T23:28:54","slug":"poor-battery-life-on-the-flame-device","status":"publish","type":"post","link":"https:\/\/blog.mozilla.org\/nnethercote\/2014\/07\/15\/poor-battery-life-on-the-flame-device\/","title":{"rendered":"Poor battery life on the Flame device?"},"content":{"rendered":"<p>The new Firefox OS reference phone is called the <a href=\"https:\/\/developer.mozilla.org\/en-US\/Firefox_OS\/Developer_phone_guide\/Flame\">Flame<\/a>. I have one that I&#8217;m using as my day-to-day phone, and as soon as I got it I found that the battery life was terrible &#8212; I use my phone very lightly, but the battery was draining in only 24 hours or so.<\/p>\n<p>It turns out this was because a kernel daemon called <a href=\"https:\/\/www.kernel.org\/doc\/Documentation\/vm\/ksm.txt\">ksmd<\/a> (kernel samepage merging daemon) was constantly running and using about 3&#8211;7% of CPU. I detected this by running the following command which prints CPU usage stats for all running processes every five seconds.<\/p>\n<pre id=\"comment_text_0\" class=\"bz_comment_text\">adb shell top -m 5<\/pre>\n<p>ksmd doesn&#8217;t seem very useful for a device such as the Flame, and Alexandre Lissy kindly built me a new kernel with it disabled, which improved my battery life by at least 3x. Details are in the <a href=\"https:\/\/bugzilla.mozilla.org\/show_bug.cgi?id=1021400\">relevant bug<\/a>.<\/p>\n<p>It seems that plenty of other Flame users are not having problems with ksmd, but if your Flame&#8217;s battery life is poor it would be worth checking if this is the cause.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The new Firefox OS reference phone is called the Flame. I have one that I&#8217;m using as my day-to-day phone, and as soon as I got it I found that the battery life was terrible &#8212; I use my phone very lightly, but the battery was draining in only 24 hours or so. It turns [&hellip;]<\/p>\n","protected":false},"author":139,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4261],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/posts\/2951"}],"collection":[{"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/users\/139"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/comments?post=2951"}],"version-history":[{"count":0,"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/posts\/2951\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/media?parent=2951"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/categories?post=2951"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.mozilla.org\/nnethercote\/wp-json\/wp\/v2\/tags?post=2951"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}