From: Daniel H <[email protected]>
To: [email protected]
Subject: Ring Setup Question
Date: Thu, 23 Apr 2020 10:38:28 -0400 [thread overview]
Message-ID: <CAAUBs7+nziOz02XPaBsP_6-4wgT3fV+VzAzgwOGAkui3K=czRQ@mail.gmail.com> (raw)
I'm working on a implementation of for the Go language and I've been running
into a failed test case that I can't understand. The test is setup in the
following manner; first write some data into a file and then read the data
back using the io_uring. The simple test case of reading back all the bytes
passes. However, when using two reads to read half the amount of data what I
observe is the second time the ring is entered (after the first read completes
successfully) is that the resulting CQE doesn't match the UserData. The test
uses a monotonically increasing value for UserData and the following debug
messages show that each entry has a unique UserData field. I'm guessing
the ring is setup properly, however I'm not sure how to proceed.
=== RUN TestRingFileReadWriterRead
pre enter
sq head: 0 tail: 1
sq entries: [{Opcode:22 Flags:2 Ioprio:0 Fd:8 Offset:0
Addr:824634362160 Len:7 UFlags:0 UserData:1 Anon0:[0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0]} {Opcode:0 Flags:0 Ioprio:0 Fd:0 Offset:0
Addr:0 Len:0 UFlags:0 UserData:0 Anon0:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0]}]
cq head: 0 tail: 0
cq entries: [{UserData:0 Res:0 Flags:0} {UserData:0 Res:0 Flags:0}]
enter complete
sq head: 1 tail: 1
sq entries: [{Opcode:22 Flags:2 Ioprio:0 Fd:8 Offset:0
Addr:824634362160 Len:7 UFlags:0 UserData:1 Anon0:[0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0]} {Opcode:0 Flags:0 Ioprio:0 Fd:0 Offset:0
Addr:0 Len:0 UFlags:0 UserData:0 Anon0:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0]}]
cq head: 1 tail: 1
cq entries: [{UserData:1 Res:7 Flags:0} {UserData:0 Res:0 Flags:0}]
pre enter
sq head: 1 tail: 2
sq entries: [{Opcode:22 Flags:2 Ioprio:0 Fd:8 Offset:0
Addr:824634362160 Len:7 UFlags:0 UserData:1 Anon0:[0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0]} {Opcode:22 Flags:2 Ioprio:0 Fd:8
Offset:7 Addr:824634363240 Len:7 UFlags:0 UserData:2 Anon0:[0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]}]
cq head: 1 tail: 1
cq entries: [{UserData:1 Res:7 Flags:0} {UserData:0 Res:0 Flags:0}]
enter complete
sq head: 2 tail: 2
sq entries: [{Opcode:22 Flags:2 Ioprio:0 Fd:8 Offset:0
Addr:824634362160 Len:7 UFlags:0 UserData:1 Anon0:[0 0 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0 0 0]} {Opcode:22 Flags:2 Ioprio:0 Fd:8
Offset:7 Addr:824634363240 Len:7 UFlags:0 UserData
:2 Anon0:[0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0]}]
cq head: 1 tail: 2
cq entries: [{UserData:1 Res:7 Flags:0} {UserData:1 Res:7 Flags:0}]
next reply other threads:[~2020-04-23 14:38 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-23 14:38 Daniel H [this message]
2020-04-23 15:24 ` Ring Setup Question Jens Axboe
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