From: Uladzislau Rezki <urezki@gmail.com>
To: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>,
LKML <linux-kernel@vger.kernel.org>, RCU <rcu@vger.kernel.org>,
linux-mm@kvack.org, "Paul E . McKenney" <paulmck@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
"Theodore Y . Ts'o" <tytso@mit.edu>,
Matthew Wilcox <willy@infradead.org>,
Joel Fernandes <joel@joelfernandes.org>,
Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Subject: Re: [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator
Date: Wed, 15 Jul 2020 21:02:43 +0200 [thread overview]
Message-ID: <20200715190243.GA26735@pc636> (raw)
In-Reply-To: <20200715185628.7b4k3o5efp4gnbla@linutronix.de>
On Wed, Jul 15, 2020 at 08:56:28PM +0200, Sebastian Andrzej Siewior wrote:
> On 2020-07-15 20:35:37 [+0200], Uladzislau Rezki (Sony) wrote:
> > @@ -3306,6 +3307,9 @@ kvfree_call_rcu_add_ptr_to_bulk(struct kfree_rcu_cpu *krcp, void *ptr)
> > if (IS_ENABLED(CONFIG_PREEMPT_RT))
> > return false;
> >
> > + preempt_disable();
> > + krc_this_cpu_unlock(*krcp, *flags);
>
> Now you enter memory allocator with disabled preemption. This isn't any
> better but we don't have a warning for this yet.
>
Please elaborate why it is not allowed? Consider the code:
<snip>
spin_lock();
__get_free_page(GFP_NOWAIT | __GFP_NOWARN);
spin_unlock();
<snip>
Also, please note we do it for regular kernel.
>
> What happened to the part where I asked for a spinlock_t?
>
What do you mean?
--
Vlad Rezki
next prev parent reply other threads:[~2020-07-15 19:02 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-15 18:35 [PATCH 1/1] rcu/tree: Drop the lock before entering to page allocator Uladzislau Rezki (Sony)
2020-07-15 18:56 ` Sebastian Andrzej Siewior
2020-07-15 19:02 ` Uladzislau Rezki [this message]
2020-07-15 19:32 ` Sebastian Andrzej Siewior
2020-07-15 19:36 ` Uladzislau Rezki
2020-07-15 22:14 ` Paul E. McKenney
2020-07-16 14:14 ` Sebastian Andrzej Siewior
2020-07-16 15:20 ` Paul E. McKenney
2020-07-16 15:36 ` Sebastian Andrzej Siewior
2020-07-16 16:36 ` Paul E. McKenney
2020-07-15 23:13 ` Joel Fernandes
2020-07-16 9:19 ` Uladzislau Rezki
2020-07-16 13:36 ` Joel Fernandes
2020-07-16 14:37 ` Uladzislau Rezki
2020-07-16 18:27 ` Joel Fernandes
2020-07-16 19:03 ` Uladzislau Rezki
2020-07-16 14:25 ` Sebastian Andrzej Siewior
2020-07-16 14:47 ` Uladzislau Rezki
2020-07-16 15:04 ` Sebastian Andrzej Siewior
2020-07-16 15:34 ` Uladzislau Rezki
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=20200715190243.GA26735@pc636 \
--to=urezki@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bigeasy@linutronix.de \
--cc=joel@joelfernandes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=oleksiy.avramchenko@sonymobile.com \
--cc=paulmck@kernel.org \
--cc=rcu@vger.kernel.org \
--cc=tytso@mit.edu \
--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).