The three major memory costs to rendering webpages in Gecko are layout, the DOM, and JavaScript.\u00a0 Only the last of these has a detailed about:memory breakdown.\u00a0 Layout has a few subcategories, but likely as not, layout\/arenas<\/tt> is one big opaque number, and DOM just sits as a big blob-o-stuff.<\/p>\n
Over the past two weeks, I’ve been working to improve this state of affairs.\u00a0 DOM’s numbers have been made more transparent by splitting out the numbers by the type of DOM node<\/a>.\u00a0 Admittedly, this isn’t perfect, as now you have several semi-opaque blobs, but it gives you a slightly better idea where the memory is going.\u00a0 Additionally, a few more things are getting counted in those DOM numbers, like some on-the-side datastructures Gecko’s DOM engine keeps around<\/a>.<\/p>\n Layout has received the most work, however.\u00a0 We now display stats for individual frame types and common objects allocated in layout’s arenas<\/a>, which can be helpful in diagnosing page performance problems (bug 686795 comment 10<\/a> and comment 23<\/a>).\u00a0 Please note that in the stats for these frames and objects, we’re not measuring any substructures contained in them, some of which could be quite significant.\u00a0 That’s a (potentially tricky<\/a>) job for later.<\/p>\n","protected":false},"excerpt":{"rendered":" The three major memory costs to rendering webpages in Gecko are layout, the DOM, and JavaScript.\u00a0 Only the last of these has a detailed about:memory breakdown.\u00a0 Layout has a few subcategories, but likely as not, layout\/arenas is one big opaque number, and DOM just sits as a big blob-o-stuff. Over the past two weeks, I’ve […]<\/p>\n","protected":false},"author":320,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/posts\/66"}],"collection":[{"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/users\/320"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/comments?post=66"}],"version-history":[{"count":0,"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/posts\/66\/revisions"}],"wp:attachment":[{"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/media?parent=66"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/categories?post=66"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.mozilla.org\/nfroyd\/wp-json\/wp\/v2\/tags?post=66"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}