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Fri, 4 Nov 2022 21:37:55 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas5p2.samsung.com (KnoxPortal) with ESMTPA id 20221104112440epcas5p24f13b6a1c3db0b38b8453a896fb31575~kXfew9FQd0031900319epcas5p2T; Fri, 4 Nov 2022 11:24:40 +0000 (GMT) Received: from epsmgms1p2.samsung.com (unknown [182.195.42.42]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20221104112440epsmtrp1f7045f8c67ab5faf0d82a4dc8101cae2~kXfewUd4J1354313543epsmtrp1c; Fri, 4 Nov 2022 11:24:40 +0000 (GMT) X-AuditID: b6c32a4b-5f7fe7000001dc20-4c-636507a32e41 Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgms1p2.samsung.com (Symantec Messaging Gateway) with SMTP id FA.34.18644.876F4636; Fri, 4 Nov 2022 20:24:40 +0900 (KST) Received: from test-zns.sa.corp.samsungelectronics.net (unknown [107.110.206.5]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20221104112438epsmtip294098ea2317d15f641dfde671be50118~kXfdS5LdT0554505545epsmtip2B; Fri, 4 Nov 2022 11:24:38 +0000 (GMT) From: Ankit Kumar To: axboe@kernel.dk Cc: fio@vger.kernel.org, vincentfu@gmail.com, Ankit Kumar Subject: [PATCH 0/2] slat and clat reporting with sqthread_poll Date: Fri, 4 Nov 2022 16:43:12 +0530 Message-Id: <20221104111314.25535-1-ankit.kumar@samsung.com> X-Mailer: git-send-email 2.17.1 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFtrDKsWRmVeSWpSXmKPExsWy7bCmuu5i9tRkg3mHpC3WXPnNbrH6bj+b xcdZL5gtNrQJOrB47Jx1l93j8tlSj74tqxg9Pm+SC2CJyrbJSE1MSS1SSM1Lzk/JzEu3VfIO jneONzUzMNQ1tLQwV1LIS8xNtVVy8QnQdcvMAVqopFCWmFMKFApILC5W0rezKcovLUlVyMgv LrFVSi1IySkwKdArTswtLs1L18tLLbEyNDAwMgUqTMjO2HLzEVPBU/6Knr/7mBoYD/F0MXJy SAiYSCw9fIe1i5GLQ0hgN6PE+1nfGSGcT4wSc59OZ4NwPjNKLJrwkRWmZf6lJewgtpDALkaJ p321EEWtTBK7frYwgSTYBLQlXr29wQxiiwgIS+zvaGUBsZkFQiVOXvsC1iwsYC8xd99UoDgH B4uAqsSui2AlvAI2Elubz7ND7JKXWL3hADPIfAmBfnaJK98/skAkXCSmLWmEsoUlXh3fAtUg JfGyvw3KzpbY9PAnE4RdIHHkRS8zhG0v0XqqnxlkL7OApsT6XfoQYVmJqafWMUGcySfR+/sJ VCuvxI55MLaqxN97t6HWSkvcfHcVyvaQOLlxCzRMYiU2fnzLPoFRdhbChgWMjKsYJVMLinPT U4tNC4zzUsvh8ZScn7uJEZyMtLx3MD568EHvECMTB+MhRgkOZiUR3k/bkpOFeFMSK6tSi/Lj i0pzUosPMZoCg2wis5Rocj4wHeaVxBuaWBqYmJmZmVgamxkqifMunqGVLCSQnliSmp2aWpBa BNPHxMEp1cCkUBx2xPUqz8u4GTP6lhzm5Tm1aWl3Uze3L/+SpCYLgc8qFaJfqrae7pgkVLuo aYNmBs+j0tMnnv17ejoukvu1ceycRpf+Ks4l+X/9Gne8kuvZs/yOWr//xrccRecvBW+/lD3j v77t+qwa23C181NfPp7JYfW78uGZWU8EZrz5v0ojYe4Nl6UJ+y7eW9NYGhYzw9HwyKNTc7N+ fzn/9WrYtd4Azcj1SserS3zehL34tHRycrJhp03lEkfFx7OmskiePVS55m6dWOhxPeYlVY9/ GGzdYtkqYlD//5B+5y0+lULb/xxsWTzib39f3ri0c+/nae8+z7v35cA67S7bb/uX/1u/6PHd XV87r70OVf4jGKjEUpyRaKjFXFScCADOaQL9zwMAAA== X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrOJMWRmVeSWpSXmKPExsWy7bCSvG7Ft5Rkg0PN4hZrrvxmt1h9t5/N 4uOsF8wWG9oEHVg8ds66y+5x+WypR9+WVYwenzfJBbBEcdmkpOZklqUW6dslcGVsufmIqeAp f0XP331MDYyHeLoYOTkkBEwk5l9awt7FyMUhJLCDUWJmw1TWLkYOoIS0xML1iRA1whIr/z2H qmlmkliy/w4jSIJNQFvi1dsbzCC2CFDR/o5WFhCbWSBcYvqByWA1wgL2EnP3TWUBmckioCqx 6yJYCa+AjcTW5vPsEPPlJVZvOMA8gZFnASPDKkbJ1ILi3PTcYsMCo7zUcr3ixNzi0rx0veT8 3E2M4LDQ0trBuGfVB71DjEwcjIcYJTiYlUR4P21LThbiTUmsrEotyo8vKs1JLT7EKM3BoiTO e6HrZLyQQHpiSWp2ampBahFMlomDU6qB6fQz/00sC8yb912+G7H36drkG2Erdq0767LpQcfu ncqTZc9E6ZrOW394wq7tH9uC13EwPyoLvbd0vYrw70TfutKpChunTAqS3ZS6Y/Las9Zmz/dO eXrdT4D5mH6i+3fWz/XNCfU1ByK6t8hY1vV4FjHEnf2hzx9dWbzS7lXAG/UO7m/b28/YiWo+ zf7xPWVZ9pWCILfNRmd2Nz/606zwTDOepdgheqq7o5fGnw4v9q2qvNN3WMso7lDew8MQ+nLh bu7ZtidFvBbpKOsePuyw7tIRnS+HpV6nnjGRCnPhfvfGN375tlbWT32Xi95/lPsYUHn8Wd2X UyFn3jN5vP94MO+j46rZts8W5dldnjzR6KASS3FGoqEWc1FxIgBlc5rdegIAAA== X-CMS-MailID: 20221104112440epcas5p24f13b6a1c3db0b38b8453a896fb31575 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20221104112440epcas5p24f13b6a1c3db0b38b8453a896fb31575 References: Precedence: bulk List-ID: X-Mailing-List: fio@vger.kernel.org When sqthread_poll is specified for io_uring and io_uring_cmd I/O engines, fio doesn't report submission latency and the completion latency is too big. Latency data before: fio --name=test --size=1M --rw=randread --ioengine=io_uring --sqthread_poll=1 clat (msec): min=1120.1k, max=1120.1k, avg=1120092.65, stdev= 8.32 lat (usec): min=104, max=5312, avg=132.81, stdev=325.05 clat percentiles (msec): | 1.00th=[17113], 5.00th=[17113], 10.00th=[17113], 20.00th=[17113], | 30.00th=[17113], 40.00th=[17113], 50.00th=[17113], 60.00th=[17113], | 70.00th=[17113], 80.00th=[17113], 90.00th=[17113], 95.00th=[17113], | 99.00th=[17113], 99.50th=[17113], 99.90th=[17113], 99.95th=[17113], | 99.99th=[17113] lat (msec) : >=2000=100.00% As kernel polling thread handles the submission, there is no way to know when the actual submission happened. We can only rely on the commit hook and measure the issue time. Latency data after the change: fio --name=test --size=1M --rw=randread --ioengine=io_uring --sqthread_poll=1 slat (nsec): min=50, max=2230, avg=146.68, stdev=138.08 clat (usec): min=105, max=5151, avg=132.98, stdev=314.89 lat (usec): min=105, max=5153, avg=133.13, stdev=315.03 clat percentiles (usec): | 1.00th=[ 106], 5.00th=[ 108], 10.00th=[ 109], 20.00th=[ 110], | 30.00th=[ 111], 40.00th=[ 113], 50.00th=[ 114], 60.00th=[ 115], | 70.00th=[ 117], 80.00th=[ 118], 90.00th=[ 119], 95.00th=[ 121], | 99.00th=[ 123], 99.50th=[ 123], 99.90th=[ 5145], 99.95th=[ 5145], | 99.99th=[ 5145] lat (usec) : 250=99.61% lat (msec) : 10=0.39% This fixes the issue: https://github.com/axboe/fio/issues/1484 Ankit Kumar (2): engines:io_uring: slat and clat calculation with sqthread_poll doc: update about sqthread_poll HOWTO.rst | 4 +++- engines/io_uring.c | 4 ++++ fio.1 | 4 +++- 3 files changed, 10 insertions(+), 2 deletions(-) -- 2.17.1