linux-kernel - Re: [PATCH] io_uring/rsrc: skip atomic refcount for uncloned buffers

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Message-Id: <175149834929.467027.590610605534865564.b4-ty@kernel.dk>
Date: Wed, 02 Jul 2025 17:19:09 -0600
From: Jens Axboe <axboe@...nel.dk>
To: Caleb Sander Mateos <csander@...estorage.com>
Cc: io-uring@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] io_uring/rsrc: skip atomic refcount for uncloned
 buffers


On Thu, 19 Jun 2025 08:34:34 -0600, Caleb Sander Mateos wrote:
> io_buffer_unmap() performs an atomic decrement of the io_mapped_ubuf's
> reference count in case it has been cloned into another io_ring_ctx's
> registered buffer table. This is an expensive operation and unnecessary
> in the common case that the io_mapped_ubuf is only registered once.
> Load the reference count first and check whether it's 1. In that case,
> skip the atomic decrement and immediately free the io_mapped_ubuf.
> 
> [...]

Applied, thanks!

[1/1] io_uring/rsrc: skip atomic refcount for uncloned buffers
      commit: daa01d954b13a178c216b6a91f8451a7b83b3bf6

Best regards,
-- 
Jens Axboe