GitHub pull request #3123 of commit 78d49f5e6296b5a6f56fdfeace0f087ff967af37, no merge conflicts.sha1origin/pr/3123/mergeghprbActualCommit78d49f5e6296b5a6f56fdfeace0f087ff967af37ghprbActualCommitAuthorghprbActualCommitAuthorEmailghprbAuthorRepoGitUrlhttps://github.com/alekseymmm/bcc.gitghprbTriggerAuthorghprbTriggerAuthorEmailghprbTriggerAuthorLoginyonghong-songghprbTriggerAuthorLoginMention@yonghong-songghprbPullId3123ghprbTargetBranchmasterghprbSourceBranchbioGIT_BRANCHbioghprbPullAuthorEmailalekseymmm@mail.rughprbPullAuthorLoginalekseymmmghprbPullAuthorLoginMention@alekseymmmghprbPullDescriptionGitHub pull request #3123 of commit 78d49f5e6296b5a6f56fdfeace0f087ff967af37, no merge conflicts.ghprbPullTitleadd latency tracing for bio-based block devicesghprbPullLinkhttps://github.com/iovisor/bcc/pull/3123ghprbPullLongDescriptionThe current behavior of biolatency.py is that it traces the submission and completion of requests in corresponding functions. Thus it only works for request-based block devices. This patch adds latency tracing for bio-based block devices. It is useful for Linux device mapper monitoring (like mdraid and lvm are common examples).\r\nI tested it on \r\n* mdraid raids\r\n* lvm volumes\r\n* null blk block devices created with queue_mode=0 (bio based)\r\n\r\nstatistics (collected with -D for example) looks like \r\n```\r\ndisk = b'dm-0'\r\n usecs : count distribution\r\n 0 -> 1 : 0 | |\r\n 2 -> 3 : 0 | |\r\n 4 -> 7 : 0 | |\r\n 8 -> 15 : 0 | |\r\n 16 -> 31 : 0 | |\r\n 32 -> 63 : 0 | |\r\n 64 -> 127 : 0 | |\r\n 128 -> 255 : 0 | |\r\n 256 -> 511 : 2 |* |\r\n 512 -> 1023 : 0 | |\r\n 1024 -> 2047 : 0 | |\r\n 2048 -> 4095 : 9 |******** |\r\n 4096 -> 8191 : 45 |****************************************|\r\n 8192 -> 16383 : 18 |**************** |\r\n```ghprbCommentBody[buildbot, test this please]ghprbGhRepositoryiovisor/bccghprbCredentialsId6d3daf13-69b8-48b1-9c8f-ec5353264113false<a title="add latency tracing for bio-based block devices" href="https://github.com/iovisor/bcc/pull/3123">PR #3123</a>: add latency tracing for bio...#70812822637460664bcc-pr #708708false7085672SUCCESS1602521775772https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/708/git708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=fc25/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=fc26/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=fc27/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=fc28/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=ubuntu1604/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=ubuntu1710/708/708https://buildbot.iovisor.org/jenkins/user/a.s.protopopov/my-views/view/all/job/bcc-pr/label=ubuntu1804/708/