From: Thomas Gleixner <tglx@linutronix.de>
To: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] genirq: add mutex and rcu locking to irq_desc_tree
Date: Tue, 31 Oct 2017 23:29:59 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.20.1710312322190.1942@nanos> (raw)
In-Reply-To: <1509416928-7450-1-git-send-email-yamada.masahiro@socionext.com>
On Tue, 31 Oct 2017, Masahiro Yamada wrote:
> Add a mutex to prevent concurrency on the updater side of the
> irq_desc radix tree.
The callers of insert/delete are already serialized by sparse_irq_lock. SO
why would we need yet another mutex?
> Add rcu_read_lock/unlock to the reader side so that lifetimes of
> leaf pointers of the radix tree are correctly managed.
That rcu protection is only needed for callers which have special life time
requirements and they have that already. For the bulk of the callers rcu
read lock is not required unless I'm missing something.
Thanks,
tglx
prev parent reply other threads:[~2017-10-31 22:30 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-31 2:28 Masahiro Yamada
2017-10-31 22:29 ` Thomas Gleixner [this message]
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=alpine.DEB.2.20.1710312322190.1942@nanos \
--to=tglx@linutronix.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=yamada.masahiro@socionext.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
all inboxes | Powered by JetHome®