Hi,

I noticed that FlushUnlockedBuffer() accepts io_object and io_context, but then 
ignores them and hardcodes IOOBJECT_RELATIONand IOCONTEXT_NORMAL instead:
```
static void
FlushUnlockedBuffer(BufferDesc *buf, SMgrRelation reln,
                                        IOObject io_object, IOContext 
io_context)
{
        Buffer          buffer = BufferDescriptorGetBuffer(buf);

        BufferLockAcquire(buffer, buf, BUFFER_LOCK_SHARE_EXCLUSIVE);
        FlushBuffer(buf, reln, IOOBJECT_RELATION, IOCONTEXT_NORMAL); // <== HERE
        BufferLockUnlock(buffer, buf);
}
```

Unless I am missing something, if a function accepts these parameters, they 
should generally be used.

FlushBuffer() seems to have the same issue. It takes both io_object and 
io_context:
```
static void
FlushBuffer(BufferDesc *buf, SMgrRelation reln, IOObject io_object,
         IOContext io_context)
```

but while io_context is used, io_object is ignored:
```
    pgstat_count_io_op_time(IOOBJECT_RELATION, io_context,
          IOOP_WRITE, io_start, 1, BLCKSZ);
```

For comparison, in AsyncReadBuffers(), where io_object is also available 
locally, it is passed through and used directly:
```
    pgstat_count_io_op_time(io_object, io_context, IOOP_READ,
          io_start, 1, io_buffers_len * BLCKSZ);
```

I raised the same point while reviewing patch [1], but that patch has not been 
updated yet.

This tiny patch just makes FlushUnlockedBuffer() and FlushBuffer() use the 
io_object and io_context values passed in by the caller.

[1] Discussion: 
https://postgr.es/m/[email protected]

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/




Attachment: v1-0001-bufmgr-pass-through-I-O-stats-context-in-FlushUnl.patch
Description: Binary data

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