{"id":1033,"date":"2026-04-01T21:26:10","date_gmt":"2026-04-01T10:26:10","guid":{"rendered":"https:\/\/securelang.net\/cms\/?p=1033"},"modified":"2026-04-01T21:26:10","modified_gmt":"2026-04-01T10:26:10","slug":"bug-hunting-day-500","status":"publish","type":"post","link":"https:\/\/securelang.net\/cms\/blog\/2026\/04\/01\/bug-hunting-day-500\/","title":{"rendered":"Bug Hunting, Day 500"},"content":{"rendered":"\n<p>It feels like I&#8217;ve been battling scheduler lockups forever.<\/p>\n\n\n\n<p>My scheduler bug is definitely due to missing some timer interrupts but it&#8217;s hard to tell exactly what&#8217;s going on as I think this only happens when booted via SBI. So the SBI firmware code manages setting up the timer, and I don&#8217;t know maybe the SBI interface is just not intended for the way I&#8217;m using it or maybe I&#8217;ve missed some other necessary initialisation on secondary cores.<\/p>\n\n\n\n<p>There is a fallback plan if I can&#8217;t get it working, which would be like a legacy mode that maxes out each CPU core in a hot loop with no interrupts. This mode would probably work okay on modern hardware and would be responsive enough in a multi-core setup but might not be useful outside of demos (would waste battery power on devices).<\/p>\n\n\n\n<p>In the longer term I need to finish the PLIC code to get all the interrupts set up properly, my short term approach will depend on whether I make a breakthrough soon or whether I get frustrated and revert to simpler ways of doing things.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>It feels like I&#8217;ve been battling scheduler lockups forever. My scheduler bug is definitely due to missing some timer interrupts but it&#8217;s hard to tell exactly what&#8217;s going on as I think this only happens when booted via SBI. So the SBI firmware code manages setting up the timer, and I don&#8217;t know maybe the [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"pagelayer_contact_templates":[],"_pagelayer_content":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-1033","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/posts\/1033","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/comments?post=1033"}],"version-history":[{"count":1,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/posts\/1033\/revisions"}],"predecessor-version":[{"id":1034,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/posts\/1033\/revisions\/1034"}],"wp:attachment":[{"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/media?parent=1033"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/categories?post=1033"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/securelang.net\/cms\/wp-json\/wp\/v2\/tags?post=1033"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}