From: Keir Fraser <keir.xen@gmail.com>
To: Jan Beulich <JBeulich@novell.com>
Cc: xen-devel@lists.xensource.com
Subject: Re: [xen-unstable test] 6947: regressions - trouble: broken/fail/pass
Date: Tue, 03 May 2011 15:09:10 +0100 [thread overview]
Message-ID: <C9E5CB16.17266%keir.xen@gmail.com> (raw)
In-Reply-To: <4DC02118020000780003F666@vpn.id2.novell.com>
On 03/05/2011 14:36, "Jan Beulich" <JBeulich@novell.com> wrote:
>> But the readers in irq context will call lookup_slot() without d->event_lock
>> held? In that case you do need an RCU-aware version of radix-tree.[ch],
>> because lookups can be occurring concurrently with insertions/deletions.
>
> No, in IRQ context we only need the irq -> pirq translation afaics, and
> that translation doesn't use an allocated object (it instead simply inserts
> the [non-zero] pirq as data item).
Ah well that makes things easier. :-) If a single lock protects all
operations (including lookups) on a particular radix tree then of course we
don't need RCU.
-- Keir
prev parent reply other threads:[~2011-05-03 14:09 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-01 19:56 [xen-unstable test] 6947: regressions - trouble: broken/fail/pass xen.org
2011-05-01 20:48 ` Keir Fraser
2011-05-02 9:01 ` Jan Beulich
2011-05-02 11:22 ` Keir Fraser
2011-05-02 12:00 ` Jan Beulich
2011-05-02 12:13 ` Keir Fraser
2011-05-02 12:24 ` Jan Beulich
2011-05-02 12:19 ` Keir Fraser
2011-05-02 12:29 ` Jan Beulich
2011-05-02 13:14 ` Keir Fraser
2011-05-02 13:39 ` Keir Fraser
2011-05-02 14:04 ` Jan Beulich
2011-05-02 15:45 ` Keir Fraser
2011-05-02 16:36 ` Dan Magenheimer
2011-05-02 17:07 ` Keir Fraser
2011-05-03 9:35 ` Jan Beulich
2011-05-03 10:09 ` Keir Fraser
2011-05-03 13:36 ` Jan Beulich
2011-05-03 14:09 ` Keir Fraser [this message]
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