From: "Paul E. McKenney" <paulmck@us.ibm.com>
To: Suzanne Wood <suzannew@cs.pdx.edu>
Cc: linux-kernel@vger.kernel.org, SteveW@ACM.org, walpole@cs.pdx.edu
Subject: Re: rcu read-side protection
Date: Tue, 16 Aug 2005 19:01:57 -0700 [thread overview]
Message-ID: <20050817020156.GF1319@us.ibm.com> (raw)
In-Reply-To: <000f01c5a2bf$f8e752d0$6401a8c0@woodworkxi42l4>
On Tue, Aug 16, 2005 at 05:09:29PM -0700, Suzanne Wood wrote:
[ . . . ]
> A read-side critical section is marked to protect the dereference of the
> dn_ptr and assignment to dn_db which is a pointer to a dn_dev. (struct
> net_device is defined in /linux/netdevice.h and its dn_ptr in
> /include/net/dn_dev.h) Should this rcu-protection be extended to the line
> following rcu_read_lock()? Even though use_long is a simple char, it
> appears to be a member of an rcu-protected structure.
Looks to me that this could indeed be a problem -- the structure
pointed to by dn_db could potentially be freed immediately after the
rcu_read_unlock(), unless there is some other non-obvious locking
mechanism protecting it. In which case, why the rcu_read_lock()
and rcu_read_unlock()...
Thanx, Paul
next prev parent reply other threads:[~2005-08-17 2:01 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-08-17 0:09 rcu read-side protection Suzanne Wood
2005-08-17 2:01 ` Paul E. McKenney [this message]
2005-08-17 8:25 ` Steven Whitehouse
2005-08-17 14:14 ` Paul E. McKenney
2005-08-17 14:45 ` Steven Whitehouse
2005-08-17 15:21 ` Patrick Caulfield
2005-08-17 19:05 ` David S. Miller
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=20050817020156.GF1319@us.ibm.com \
--to=paulmck@us.ibm.com \
--cc=SteveW@ACM.org \
--cc=linux-kernel@vger.kernel.org \
--cc=suzannew@cs.pdx.edu \
--cc=walpole@cs.pdx.edu \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.