linux-kernel - Re: [PATCH] vfs: only read fops once in fops

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Message-ID: <20240809-kompendium-zylinder-270cabc854d4@brauner>
Date: Fri,  9 Aug 2024 10:30:42 +0200
From: Christian Brauner <brauner@...nel.org>
To: Mateusz Guzik <mjguzik@...il.com>
Cc: Christian Brauner <brauner@...nel.org>,
	viro@...iv.linux.org.uk,
	jack@...e.cz,
	linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] vfs: only read fops once in fops_get/put

On Thu, 08 Aug 2024 17:54:28 +0200, Mateusz Guzik wrote:
> The compiler emits 2 access in fops_get(), put is patched to maintain some
> consistency.
> 
> This makes do_dentry_open() go down from 1177 to 1154 bytes.
> 
> This popped up due to false-sharing where loads from inode->i_fop end up
> bouncing a cacheline on parallel open. While this is going to be fixed,
> the spurious load does not need to be there.
> 
> [...]

Applied to the vfs.misc branch of the vfs/vfs.git tree.
Patches in the vfs.misc branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs.misc

[1/1] vfs: only read fops once in fops_get/put
      https://git.kernel.org/vfs/vfs/c/2a2dc5eb79c4