From: Al Viro <viro@zeniv.linux.org.uk>
To: Pavel Begunkov <asml.silence@gmail.com>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fs: optimise generic_write_check_limits()
Date: Fri, 6 Aug 2021 13:46:28 +0000 [thread overview]
Message-ID: <YQ09NFOPz/K3sDV6@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <dc92d8ac746eaa95e5c22ca5e366b824c210a3f4.1628248828.git.asml.silence@gmail.com>
On Fri, Aug 06, 2021 at 12:22:10PM +0100, Pavel Begunkov wrote:
> Even though ->s_maxbytes is used by generic_write_check_limits() only in
> case of O_LARGEFILE, the value is loaded unconditionally, which is heavy
> and takes 4 indirect loads. Optimise it by not touching ->s_maxbytes,
> if it's not going to be used.
Out of curiosity - how much of improvement have you actually seen on that?
I can't say I hate the patch, but I'd like to see the data...
prev parent reply other threads:[~2021-08-06 13:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-06 11:22 [PATCH] fs: optimise generic_write_check_limits() Pavel Begunkov
2021-08-06 13:28 ` Matthew Wilcox
2021-08-07 10:05 ` Pavel Begunkov
2021-08-08 14:41 ` David Laight
2021-08-08 15:34 ` Matthew Wilcox
2021-08-06 13:46 ` Al Viro [this message]
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