Re: [RFC PATCH v3 0/3] introduce io_uring_cmd_import_fixed_vec

[Mark Harmstone <maharmstone@meta.com>]

On 16/3/25 07:22, Pavel Begunkov wrote:
> > 
> On 3/15/25 17:23, Sidong Yang wrote:
>> This patche series introduce io_uring_cmd_import_vec. With this function,
>> Multiple fixed buffer could be used in uring cmd. It's vectored version
>> for io_uring_cmd_import_fixed(). Also this patch series includes a usage
>> for new api for encoded read/write in btrfs by using uring cmd.
>>
>> There was approximately 10 percent of performance improvements through 
>> benchmark.
>> The benchmark code is in
>> https://github.com/SidongYang/btrfs-encoded-io-test/blob/main/main.c
>> ./main -l
>> Elapsed time: 0.598997 seconds
>> ./main -l -f
>> Elapsed time: 0.540332 seconds
> 
> It's probably precise, but it's usually hard to judge about
> performance from such short runs. Mark, do we have some benchmark
> for the io_uring cmd?

Unfortunately not. My plan was to plug it in to btrfs-receive and to use 
that as a benchmark, but it turned out that the limiting factor there 
was the dentry locking.

Sidong, Pavel is right - your figures would be more useful if you ran it 
1,000 times or so.

Mark