From: Christoph Hellwig <hch@lst.de>
To: Kanchan Joshi <joshi.k@samsung.com>
Cc: kbusch@kernel.org, hch@lst.de, axboe@kernel.dk,
linux-block@vger.kernel.org, martin.petersen@oracle.com,
anuj20.g@samsung.com
Subject: Re: [PATCH] block: streamline meta bounce buffer handling
Date: Mon, 6 May 2024 08:05:09 +0200 [thread overview]
Message-ID: <20240506060509.GA5362@lst.de> (raw)
In-Reply-To: <20240506051047.4291-1-joshi.k@samsung.com>
Can we take a step back first?
Current the blk-map user buffer handling decided to either pin
the memory and use that directly or use the normal user copy helpers
through copy_page_to_iter/copy_page_from_iter.
Why do we even pin the memory here to then do an in-kernel copy instead
of doing the copy_from/to_user which is going to be a lot more efficient?
Sort of related to that is that this does driver the copy to user and
unpin from bio_integrity_free, which is a low-level routine. It really
should be driven from the highlevel blk-map code that is the I/O
submitter, just like the data side. Shoe-horning uaccess into the
low-level block layer plumbing is just going to get us into trouble.
next prev parent reply other threads:[~2024-05-06 6:05 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20240506051751epcas5p1ed84e21495e12c7bf41e94827aa85e33@epcas5p1.samsung.com>
2024-05-06 5:10 ` [PATCH] block: streamline meta bounce buffer handling Kanchan Joshi
2024-05-06 6:05 ` Christoph Hellwig [this message]
2024-05-06 12:46 ` Kanchan Joshi
2024-05-06 14:56 ` Christoph Hellwig
2024-05-06 20:36 ` Keith Busch
2024-05-07 5:45 ` Christoph Hellwig
2024-05-24 10:28 ` Kanchan Joshi
2024-05-28 7:59 ` Christoph Hellwig
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240506060509.GA5362@lst.de \
--to=hch@lst.de \
--cc=anuj20.g@samsung.com \
--cc=axboe@kernel.dk \
--cc=joshi.k@samsung.com \
--cc=kbusch@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=martin.petersen@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.