)]}'
{"id":"userspace-rcu~8446","triplet_id":"userspace-rcu~master~I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2","project":"userspace-rcu","branch":"master","topic":"fix-futex-race","attention_set":{},"removed_from_attention_set":{"1000009":{"account":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"last_update":"2022-06-27 14:30:14.000000000","reason":"Change was submitted"}},"hashtags":[],"change_id":"I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2","subject":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups","status":"MERGED","created":"2022-06-22 20:50:52.000000000","updated":"2022-06-27 14:30:14.000000000","submitted":"2022-06-27 14:30:14.000000000","submitter":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"total_comment_count":0,"unresolved_comment_count":0,"has_review_started":true,"submission_id":"8441-fix-futex-race","meta_rev_id":"2f16961fd37f23e1b6a1851cdbea799aeb1272e7","_number":8446,"virtual_id_number":8446,"owner":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"actions":{},"labels":{"Code-Review":{"all":[{"value":0,"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},{"value":0,"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]}],"values":{"-2":"This shall not be merged","-1":"I would prefer this is not merged as is"," 0":"No score","+1":"Looks good to me, but someone else must approve","+2":"Looks good to me, approved"},"description":"","default_value":0,"optional":true},"Verified":{"rejected":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"all":[{"value":0,"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},{"tag":"autogenerated:jenkins-gerrit-trigger","value":-2,"date":"2022-06-27 14:30:14.000000000","permitted_voting_range":{"min":-2,"max":2},"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]}],"values":{"-2":"Failure","-1":"Not built"," 0":"No score","+1":"Unstable","+2":"Success"},"description":"CI Build results","default_value":0,"optional":true},"CI-Build":{"approved":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"all":[{"value":1,"date":"2022-06-27 14:30:14.000000000","_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},{"value":0,"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]}],"values":{" 0":"No score","+1":"Trigger a CI build"},"description":"Trigger CI builds","default_value":0,"optional":true},"Smoke-Build-Lvl1":{"all":[{"value":0,"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},{"value":0,"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]}],"values":{" 0":"No score","+1":"Trigger a level 1 smoke build"},"description":"Trigger Level 1 Smoke builds","default_value":0,"optional":true},"Smoke-Build-Lvl2":{"all":[{"value":0,"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},{"value":0,"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]}],"values":{" 0":"No score","+1":"Trigger a level 2 smoke build"},"description":"Trigger Level 2 Smoke builds","default_value":0,"optional":true}},"removable_reviewers":[],"reviewers":{"REVIEWER":[{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]}]},"pending_reviewers":{},"reviewer_updates":[{"updated":"2022-06-23 20:37:18.000000000","updated_by":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"reviewer":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"state":"CC"},{"updated":"2022-06-24 03:11:43.000000000","updated_by":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"reviewer":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"state":"REVIEWER"}],"messages":[{"id":"9fe84306dd6d05e80d796460086f3829ab02bcd4","tag":"autogenerated:gerrit:newPatchSet","author":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"date":"2022-06-22 20:50:52.000000000","message":"Uploaded patch set 1.","accounts_in_message":[],"_revision_number":1},{"id":"7635fd3921d2d46ad9ac1574e9b919b00056af6e","tag":"autogenerated:gerrit:newPatchSet","author":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"date":"2022-06-23 19:09:31.000000000","message":"Uploaded patch set 2: Commit message was updated.","accounts_in_message":[],"_revision_number":2},{"id":"db434be7bea70283cf101afc4db3e9cae98001a5","tag":"autogenerated:gerrit:newPatchSet","author":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"date":"2022-06-23 19:56:57.000000000","message":"Uploaded patch set 3: Patch Set 2 was rebased.","accounts_in_message":[],"_revision_number":3},{"id":"b3f51d6fc709d1c71c94352ba2e4d6f6470be90e","author":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"date":"2022-06-23 20:37:12.000000000","message":"Patch Set 3: CI-Build+1","accounts_in_message":[],"_revision_number":3},{"id":"5de04fab12d8d99ea735b40e922734dfb2f79f85","tag":"autogenerated:jenkins-gerrit-trigger","author":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"date":"2022-06-23 20:37:18.000000000","message":"Patch Set 3:\n\nBuild Started https://ci.lttng.org/job/dev_gerrit_liburcu_build/91/ (1/2)","accounts_in_message":[],"_revision_number":3},{"id":"f127f79444a986ec14a46b34afab8c5b72831625","tag":"autogenerated:jenkins-gerrit-trigger","author":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"date":"2022-06-23 20:37:18.000000000","message":"Patch Set 3:\n\nBuild Started https://ci.lttng.org/job/dev_gerrit_liburcu_portbuild/91/ (2/2)","accounts_in_message":[],"_revision_number":3},{"id":"33efca17fec894a8df73e273c5cf5cba72a49120","tag":"autogenerated:jenkins-gerrit-trigger","author":{"_account_id":1000002,"name":"jenkins","email":"jenkins@lttng.org","username":"jenkins","avatars":[{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/e3f1da3d4191917309975c0380f40764.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}],"tags":["SERVICE_USER"]},"date":"2022-06-24 03:11:43.000000000","message":"Patch Set 3: Verified-2\n\nBuild Failed \n\nhttps://ci.lttng.org/job/dev_gerrit_liburcu_build/91/ : FAILURE\n\nhttps://ci.lttng.org/job/dev_gerrit_liburcu_portbuild/91/ : UNSTABLE","accounts_in_message":[],"_revision_number":3},{"id":"2f16961fd37f23e1b6a1851cdbea799aeb1272e7","tag":"autogenerated:gerrit:merged","author":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"date":"2022-06-27 14:30:14.000000000","message":"Change has been successfully pushed.","accounts_in_message":[],"_revision_number":4}],"current_revision_number":4,"current_revision":"4974ad5f21d2cb17d313504f8d1252738526d588","revisions":{"837b24f931b48c6e8b9fc0d4b9548676e5ff09ee":{"kind":"REWORK","_number":1,"created":"2022-06-22 20:50:52.000000000","uploader":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"ref":"refs/changes/46/8446/1","fetch":{"anonymous http":{"url":"https://review.lttng.org/userspace-rcu","ref":"refs/changes/46/8446/1","commands":{"Branch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/1 \u0026\u0026 git checkout -b change-8446 FETCH_HEAD","Checkout":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/1 \u0026\u0026 git checkout FETCH_HEAD","Cherry Pick":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/1 \u0026\u0026 git cherry-pick FETCH_HEAD","Format Patch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/1 \u0026\u0026 git format-patch -1 --stdout FETCH_HEAD","Pull":"git pull https://review.lttng.org/userspace-rcu refs/changes/46/8446/1","Reset To":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/1 \u0026\u0026 git reset --hard FETCH_HEAD"}}},"commit":{"parents":[{"commit":"0238ccf481c21f93929392012005b4ef7faf27ed","subject":"Fix: defer_rcu: futex wait: handle spurious futex wakeups","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d0238ccf481c21f93929392012005b4ef7faf27ed"}]}],"author":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-22 20:49:11.000000000","tz":-240},"committer":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-22 20:49:11.000000000","tz":-240},"subject":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups","message":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups\n\nFrom futex(5):\n\n       FUTEX_WAIT\n              Returns 0 if the caller was woken up.  Note that a  wake-up  can\n              also  be caused by common futex usage patterns in unrelated code\n              that happened to have previously used the  futex  word\u0027s  memory\n              location  (e.g., typical futex-based implementations of Pthreads\n              mutexes can cause this under some conditions).  Therefore, call‐\n              ers should always conservatively assume that a return value of 0\n              can mean a spurious wake-up, and  use  the  futex  word\u0027s  value\n              (i.e.,  the user-space synchronization scheme) to decide whether\n              to continue to block or not.\n\nWe therefore need to validate whether the value differs from -1 in\nuser-space after the call to FUTEX_WAIT returns 0.\n\nSigned-off-by: Mathieu Desnoyers \u003cmathieu.desnoyers@efficios.com\u003e\nChange-Id: I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2\n","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d837b24f931b48c6e8b9fc0d4b9548676e5ff09ee"}],"resolve_conflicts_web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d837b24f931b48c6e8b9fc0d4b9548676e5ff09ee"}]},"branch":"refs/heads/master"},"428e3c5c3704dc107d97e9335af830503beb8a65":{"kind":"NO_CODE_CHANGE","_number":2,"created":"2022-06-23 19:09:31.000000000","uploader":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"ref":"refs/changes/46/8446/2","fetch":{"anonymous http":{"url":"https://review.lttng.org/userspace-rcu","ref":"refs/changes/46/8446/2","commands":{"Branch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/2 \u0026\u0026 git checkout -b change-8446 FETCH_HEAD","Checkout":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/2 \u0026\u0026 git checkout FETCH_HEAD","Cherry Pick":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/2 \u0026\u0026 git cherry-pick FETCH_HEAD","Format Patch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/2 \u0026\u0026 git format-patch -1 --stdout FETCH_HEAD","Pull":"git pull https://review.lttng.org/userspace-rcu refs/changes/46/8446/2","Reset To":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/2 \u0026\u0026 git reset --hard FETCH_HEAD"}}},"commit":{"parents":[{"commit":"d7568d3b513f442b24e5152713ecfa8393daf686","subject":"Fix: urcu: futex wait: handle spurious futex wakeups","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003dd7568d3b513f442b24e5152713ecfa8393daf686"}]}],"author":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-22 20:49:11.000000000","tz":-240},"committer":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-23 19:09:31.000000000","tz":-240},"subject":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups","message":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups\n\nObserved issue\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nThe urcu-qsbr wait_gp() implements a futex wait/wakeup scheme identical to\nthe workqueue code, which has an issue with spurious wakeups.\n\nA spurious wakeup on wait_gp can cause wait_gp to return with a\nurcu_qsbr_gp.futex state of -1, which is unexpected. It would cause the\nfollowing loops in wait_for_readers() to decrement the\nurcu_qsbr_gp.futex to values below -1, thus actively using CPU as values\nwill be decremented to very low negative values until it reaches 0\nthrough underflow, or until the input_readers list is found to be empty.\nThe state is restored to 0 when the input_readers list is found to be\nempty, which restores the futex state to a correct state for the\nfollowing calls to wait_for_readers().\n\nThis issue will cause spurious unexpected high CPU use, but will not\nlead to data corruption.\n\nCause\n\u003d\u003d\u003d\u003d\u003d\n\nFrom futex(5):\n\n       FUTEX_WAIT\n              Returns 0 if the caller was woken up.  Note that a  wake-up  can\n              also  be caused by common futex usage patterns in unrelated code\n              that happened to have previously used the  futex  word\u0027s  memory\n              location  (e.g., typical futex-based implementations of Pthreads\n              mutexes can cause this under some conditions).  Therefore, call‐\n              ers should always conservatively assume that a return value of 0\n              can mean a spurious wake-up, and  use  the  futex  word\u0027s  value\n              (i.e.,  the user-space synchronization scheme) to decide whether\n              to continue to block or not.\n\nSolution\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nWe therefore need to validate whether the value differs from -1 in\nuser-space after the call to FUTEX_WAIT returns 0.\n\nKnown drawbacks\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nNone.\n\nSigned-off-by: Mathieu Desnoyers \u003cmathieu.desnoyers@efficios.com\u003e\nChange-Id: I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2\n","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d428e3c5c3704dc107d97e9335af830503beb8a65"}],"resolve_conflicts_web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d428e3c5c3704dc107d97e9335af830503beb8a65"}]},"branch":"refs/heads/master"},"010b6c54ed78d503d14389c8b8a84f163c1a9e26":{"kind":"TRIVIAL_REBASE","_number":3,"created":"2022-06-23 19:56:57.000000000","uploader":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"ref":"refs/changes/46/8446/3","fetch":{"anonymous http":{"url":"https://review.lttng.org/userspace-rcu","ref":"refs/changes/46/8446/3","commands":{"Branch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/3 \u0026\u0026 git checkout -b change-8446 FETCH_HEAD","Checkout":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/3 \u0026\u0026 git checkout FETCH_HEAD","Cherry Pick":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/3 \u0026\u0026 git cherry-pick FETCH_HEAD","Format Patch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/3 \u0026\u0026 git format-patch -1 --stdout FETCH_HEAD","Pull":"git pull https://review.lttng.org/userspace-rcu refs/changes/46/8446/3","Reset To":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/3 \u0026\u0026 git reset --hard FETCH_HEAD"}}},"commit":{"parents":[{"commit":"4be1856d8fe7f37c8515302848cc944ed7a53e49","subject":"Fix: urcu: futex wait: handle spurious futex wakeups","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d4be1856d8fe7f37c8515302848cc944ed7a53e49"}]}],"author":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-22 20:49:11.000000000","tz":-240},"committer":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-23 19:56:50.000000000","tz":-240},"subject":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups","message":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups\n\nObserved issue\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nThe urcu-qsbr wait_gp() implements a futex wait/wakeup scheme identical to\nthe workqueue code, which has an issue with spurious wakeups.\n\nA spurious wakeup on wait_gp can cause wait_gp to return with a\nurcu_qsbr_gp.futex state of -1, which is unexpected. It would cause the\nfollowing loops in wait_for_readers() to decrement the\nurcu_qsbr_gp.futex to values below -1, thus actively using CPU as values\nwill be decremented to very low negative values until it reaches 0\nthrough underflow, or until the input_readers list is found to be empty.\nThe state is restored to 0 when the input_readers list is found to be\nempty, which restores the futex state to a correct state for the\nfollowing calls to wait_for_readers().\n\nThis issue will cause spurious unexpected high CPU use, but will not\nlead to data corruption.\n\nCause\n\u003d\u003d\u003d\u003d\u003d\n\nFrom futex(5):\n\n       FUTEX_WAIT\n              Returns 0 if the caller was woken up.  Note that a  wake-up  can\n              also  be caused by common futex usage patterns in unrelated code\n              that happened to have previously used the  futex  word\u0027s  memory\n              location  (e.g., typical futex-based implementations of Pthreads\n              mutexes can cause this under some conditions).  Therefore, call‐\n              ers should always conservatively assume that a return value of 0\n              can mean a spurious wake-up, and  use  the  futex  word\u0027s  value\n              (i.e.,  the user-space synchronization scheme) to decide whether\n              to continue to block or not.\n\nSolution\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nWe therefore need to validate whether the value differs from -1 in\nuser-space after the call to FUTEX_WAIT returns 0.\n\nKnown drawbacks\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nNone.\n\nSigned-off-by: Mathieu Desnoyers \u003cmathieu.desnoyers@efficios.com\u003e\nChange-Id: I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2\n","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d010b6c54ed78d503d14389c8b8a84f163c1a9e26"}],"resolve_conflicts_web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d010b6c54ed78d503d14389c8b8a84f163c1a9e26"}]},"branch":"refs/heads/master"},"4974ad5f21d2cb17d313504f8d1252738526d588":{"kind":"NO_CHANGE","_number":4,"created":"2022-06-27 14:30:14.000000000","uploader":{"_account_id":1000009,"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","username":"compudj","avatars":[{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d32","height":32},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d56","height":56},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d100","height":100},{"url":"https://www.gravatar.com/avatar/7326b3e1d32b971a5e69d9730228c428.jpg?d\u003dretro\u0026r\u003dr\u0026s\u003d120","height":120}]},"ref":"refs/changes/46/8446/4","fetch":{"anonymous http":{"url":"https://review.lttng.org/userspace-rcu","ref":"refs/changes/46/8446/4","commands":{"Branch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/4 \u0026\u0026 git checkout -b change-8446 FETCH_HEAD","Checkout":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/4 \u0026\u0026 git checkout FETCH_HEAD","Cherry Pick":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/4 \u0026\u0026 git cherry-pick FETCH_HEAD","Format Patch":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/4 \u0026\u0026 git format-patch -1 --stdout FETCH_HEAD","Pull":"git pull https://review.lttng.org/userspace-rcu refs/changes/46/8446/4","Reset To":"git fetch https://review.lttng.org/userspace-rcu refs/changes/46/8446/4 \u0026\u0026 git reset --hard FETCH_HEAD"}}},"commit":{"parents":[{"commit":"a18d0428065b301086d4e8a85bc057dc39946891","subject":"Fix: urcu: futex wait: handle spurious futex wakeups","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003da18d0428065b301086d4e8a85bc057dc39946891"}]}],"author":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-22 20:49:11.000000000","tz":-240},"committer":{"name":"Mathieu Desnoyers","email":"mathieu.desnoyers@efficios.com","date":"2022-06-27 14:30:13.000000000","tz":-240},"subject":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups","message":"Fix: urcu-qsbr: futex wait: handle spurious futex wakeups\n\nObserved issue\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nThe urcu-qsbr wait_gp() implements a futex wait/wakeup scheme identical to\nthe workqueue code, which has an issue with spurious wakeups.\n\nA spurious wakeup on wait_gp can cause wait_gp to return with a\nurcu_qsbr_gp.futex state of -1, which is unexpected. It would cause the\nfollowing loops in wait_for_readers() to decrement the\nurcu_qsbr_gp.futex to values below -1, thus actively using CPU as values\nwill be decremented to very low negative values until it reaches 0\nthrough underflow, or until the input_readers list is found to be empty.\nThe state is restored to 0 when the input_readers list is found to be\nempty, which restores the futex state to a correct state for the\nfollowing calls to wait_for_readers().\n\nThis issue will cause spurious unexpected high CPU use, but will not\nlead to data corruption.\n\nCause\n\u003d\u003d\u003d\u003d\u003d\n\nFrom futex(5):\n\n       FUTEX_WAIT\n              Returns 0 if the caller was woken up.  Note that a  wake-up  can\n              also  be caused by common futex usage patterns in unrelated code\n              that happened to have previously used the  futex  word\u0027s  memory\n              location  (e.g., typical futex-based implementations of Pthreads\n              mutexes can cause this under some conditions).  Therefore, call‐\n              ers should always conservatively assume that a return value of 0\n              can mean a spurious wake-up, and  use  the  futex  word\u0027s  value\n              (i.e.,  the user-space synchronization scheme) to decide whether\n              to continue to block or not.\n\nSolution\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nWe therefore need to validate whether the value differs from -1 in\nuser-space after the call to FUTEX_WAIT returns 0.\n\nKnown drawbacks\n\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\u003d\n\nNone.\n\nSigned-off-by: Mathieu Desnoyers \u003cmathieu.desnoyers@efficios.com\u003e\nChange-Id: I87f7cd3b02820cefe850c3bdb8da27fb2f9be9b2\n","web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d4974ad5f21d2cb17d313504f8d1252738526d588"}],"resolve_conflicts_web_links":[{"name":"gitweb","tooltip":"Open in GitWeb","url":"/gitweb?p\u003duserspace-rcu.git;a\u003dcommit;h\u003d4974ad5f21d2cb17d313504f8d1252738526d588"}]},"branch":"refs/heads/master"}},"requirements":[],"submit_records":[],"submit_requirements":[]}