From: Jan Kara <jack@suse.cz>
To: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>, Dan Williams <dan.j.williams@intel.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Boaz Harrosh <openosd@gmail.com>, stable <stable@vger.kernel.org>,
Robert Barror <robert.barror@intel.com>,
Seema Pandit <seema.pandit@intel.com>,
linux-nvdimm <linux-nvdimm@lists.01.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] dax: Fix missed PMD wakeups
Date: Thu, 11 Jul 2019 09:48:59 +0200 [thread overview]
Message-ID: <20190711074859.GA8727@quack2.suse.cz> (raw)
In-Reply-To: <20190711030855.GO32320@bombadil.infradead.org>
On Wed 10-07-19 20:08:55, Matthew Wilcox wrote:
> On Wed, Jul 10, 2019 at 09:02:04PM +0200, Jan Kara wrote:
> > @@ -848,7 +853,7 @@ static int dax_writeback_one(struct xa_state *xas, struct dax_device *dax_dev,
> > if (unlikely(dax_is_locked(entry))) {
> > void *old_entry = entry;
> >
> > - entry = get_unlocked_entry(xas);
> > + entry = get_unlocked_entry(xas, 0);
> >
> > /* Entry got punched out / reallocated? */
> > if (!entry || WARN_ON_ONCE(!xa_is_value(entry)))
>
> I'm not sure about this one. Are we sure there will never be a dirty
> PMD entry? Even if we can't create one today, it feels like a bit of
> a landmine to leave for someone who creates one in the future.
I was thinking about this but dax_writeback_one() doesn't really care what
entry it gets. Yes, in theory it could get a PMD when previously there was
PTE or vice-versa but we check that PFN's match and if they really do
match, there's no harm in doing the flushing whatever entry we got back...
And the checks are simpler this way.
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
next prev parent reply other threads:[~2019-07-11 7:57 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-03 7:24 [PATCH] dax: Fix missed PMD wakeups Dan Williams
2019-07-03 12:17 ` Matthew Wilcox
2019-07-03 17:01 ` Dan Williams
2019-07-03 19:53 ` Matthew Wilcox
2019-07-03 21:28 ` Dan Williams
2019-07-04 3:27 ` Matthew Wilcox
2019-07-04 13:00 ` Boaz Harrosh
2019-07-04 13:58 ` Matthew Wilcox
2019-07-04 14:32 ` Boaz Harrosh
2019-07-04 16:54 ` Jan Kara
2019-07-04 19:14 ` Matthew Wilcox
2019-07-04 23:27 ` Dan Williams
2019-07-05 19:10 ` Matthew Wilcox
2019-07-05 20:47 ` Dan Williams
2019-07-10 19:02 ` Jan Kara
2019-07-10 20:15 ` Matthew Wilcox
2019-07-10 20:26 ` Jan Kara
2019-07-11 14:13 ` Matthew Wilcox
2019-07-11 15:25 ` Matthew Wilcox
2019-07-11 15:41 ` Jan Kara
2019-07-17 3:39 ` Dan Williams
2019-07-29 12:02 ` Jan Kara
2019-07-29 15:18 ` Dan Williams
2019-07-11 3:08 ` Matthew Wilcox
2019-07-11 7:48 ` Jan Kara [this message]
2019-07-11 13:28 ` Matthew Wilcox
2019-07-11 3:35 ` Matthew Wilcox
2019-07-11 8:06 ` Jan Kara
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=20190711074859.GA8727@quack2.suse.cz \
--to=jack@suse.cz \
--cc=dan.j.williams@intel.com \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvdimm@lists.01.org \
--cc=openosd@gmail.com \
--cc=robert.barror@intel.com \
--cc=seema.pandit@intel.com \
--cc=stable@vger.kernel.org \
--cc=willy@infradead.org \
/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).