On Thu, Mar 13, 2025 at 08:57:45AM +0000, Pavel Begunkov wrote: > On 3/12/25 14:23, 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 in btrfs by using uring cmd. > > Pretty much same thing, we're still left with 2 allocations in the > hot path. What I think we can do here is to add caching on the > io_uring side as we do with rw / net, but that would be invisible > for cmd drivers. And that cache can be reused for normal iovec imports. > > https://github.com/isilence/linux.git regvec-import-cmd > (link for convenience) > https://github.com/isilence/linux/tree/regvec-import-cmd > > Not really target tested, no btrfs, not any other user, just an idea. > There are 4 patches, but the top 3 are of interest. Thanks, I justed checked the commits now. I think cache is good to resolve this without allocation if cache hit. Let me reimpl this idea and test it for btrfs. > > Another way would be to cache in btrfs, but then btrfs would need to > care about locking for the cache and some other bits, and we wouldn't > be able to reuse it for other drivers. Agreed, it could be better to reuse it for other driver. Thanks, Sidong > > -- > Pavel Begunkov >
