From: Matthew Wilcox <willy@infradead.org>
To: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org,
nvdimm@lists.linux.dev, linux-mm@kvack.org,
linux-fsdevel@vger.kernel.org, dm-devel@redhat.com,
darrick.wong@oracle.com, dan.j.williams@intel.com,
david@fromorbit.com, hch@lst.de, agk@redhat.com,
snitzer@redhat.com, rgoldwyn@suse.de
Subject: Re: [PATCH v5 5/9] mm: Introduce mf_dax_kill_procs() for fsdax case
Date: Mon, 28 Jun 2021 12:49:41 +0100 [thread overview]
Message-ID: <YNm3VeeWuI0m4Vcx@casper.infradead.org> (raw)
In-Reply-To: <20210628000218.387833-6-ruansy.fnst@fujitsu.com>
On Mon, Jun 28, 2021 at 08:02:14AM +0800, Shiyang Ruan wrote:
> +/*
> + * dax_load_pfn - Load pfn of the DAX entry corresponding to a page
> + * @mapping: The file whose entry we want to load
> + * @index: offset where the DAX entry located in
> + *
> + * Return: pfn number of the DAX entry
> + */
This is an externally visible function; why not add the second '*' and
make this kernel-doc?
> +unsigned long dax_load_pfn(struct address_space *mapping, unsigned long index)
> +{
> + XA_STATE(xas, &mapping->i_pages, index);
> + void *entry;
> + unsigned long pfn;
> +
> + xas_lock_irq(&xas);
> + entry = xas_load(&xas);
> + pfn = dax_to_pfn(entry);
> + xas_unlock_irq(&xas);
Why do you need the i_pages lock to do this? is the rcu_read_lock()
insufficient? For that matter, why use the xas functions? Why not
simply:
void *entry = xa_load(&mapping->i_pages, index);
return dax_to_pfn(entry);
Looking at it more though, how do you know this is a PFN entry?
It could be locked, for example. Or the zero page, or empty.
But I think this is unnecessary; why not just pass the PFN into
mf_dax_kill_procs?
next prev parent reply other threads:[~2021-06-28 11:50 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-28 0:02 [PATCH v5 0/9] fsdax: introduce fs query to support reflink Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 1/9] pagemap: Introduce ->memory_failure() Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 2/9] dax: Introduce holder for dax_device Shiyang Ruan
2021-07-19 15:17 ` Christoph Hellwig
2021-07-20 10:37 ` ruansy.fnst
2021-06-28 0:02 ` [PATCH v5 3/9] mm: factor helpers for memory_failure_dev_pagemap Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 4/9] pmem,mm: Implement ->memory_failure in pmem driver Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 5/9] mm: Introduce mf_dax_kill_procs() for fsdax case Shiyang Ruan
2021-06-28 3:23 ` kernel test robot
2021-06-28 11:49 ` Matthew Wilcox [this message]
2021-06-29 7:49 ` ruansy.fnst
2021-06-29 11:46 ` Matthew Wilcox
2021-07-16 6:32 ` ruansy.fnst
2021-06-28 0:02 ` [PATCH v5 6/9] xfs: Implement ->corrupted_range() for XFS Shiyang Ruan
2021-06-28 2:02 ` kernel test robot
2021-06-28 3:05 ` kernel test robot
2021-06-28 0:02 ` [PATCH v5 7/9] dm: Introduce ->rmap() to find bdev offset Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 8/9] md: Implement dax_holder_operations Shiyang Ruan
2021-06-28 0:02 ` [PATCH v5 9/9] fs/dax: Remove useless functions Shiyang Ruan
2021-07-19 15:18 ` 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=YNm3VeeWuI0m4Vcx@casper.infradead.org \
--to=willy@infradead.org \
--cc=agk@redhat.com \
--cc=dan.j.williams@intel.com \
--cc=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=dm-devel@redhat.com \
--cc=hch@lst.de \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-xfs@vger.kernel.org \
--cc=nvdimm@lists.linux.dev \
--cc=rgoldwyn@suse.de \
--cc=ruansy.fnst@fujitsu.com \
--cc=snitzer@redhat.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).