From: Peter Zijlstra <peterz@infradead.org>
To: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org, Alexei Starovoitov <ast@kernel.org>,
Christian Brauner <christian@brauner.io>,
Daniel Borkmann <daniel@iogearbox.net>,
David Ahern <dsahern@gmail.com>,
"David S. Miller" <davem@davemloft.net>,
Ido Schimmel <idosch@mellanox.com>,
Ingo Molnar <mingo@redhat.com>,
"moderated list:INTEL ETHERNET DRIVERS"
<intel-wired-lan@lists.osuosl.org>,
Jakub Kicinski <jakub.kicinski@netronome.com>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
Jesper Dangaard Brouer <hawk@kernel.org>,
John Fastabend <john.fastabend@gmail.com>,
Josh Triplett <josh@joshtriplett.org>,
keescook@chromium.org, Lai Jiangshan <jiangshanlai@gmail.com>,
Martin KaFai Lau <kafai@fb.com>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
netdev@vger.kernel.org,
"Paul E. McKenney" <paulmck@linux.ibm.com>,
rcu@vger.kernel.org, Song Liu <songliubraving@fb.com>,
Steven Rostedt <rostedt@goodmis.org>,
xdp-newbies@vger.kernel.org, Yonghong Song <yhs@fb.com>
Subject: Re: [PATCH RFC 5/5] rcuwait: Replace rcu_assign_pointer() with WRITE_ONCE
Date: Thu, 21 Feb 2019 10:20:20 +0100 [thread overview]
Message-ID: <20190221092020.GZ32477@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20190221054942.132388-6-joel@joelfernandes.org>
On Thu, Feb 21, 2019 at 12:49:42AM -0500, Joel Fernandes (Google) wrote:
> This suppresses a sparse error generated due to the recently added
> rcu_assign_pointer sparse check below. It seems WRITE_ONCE should be
> sufficient here.
>
> >> kernel//locking/percpu-rwsem.c:162:9: sparse: error: incompatible
> types in comparison expression (different address spaces)
>
> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> ---
> include/linux/rcuwait.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/rcuwait.h b/include/linux/rcuwait.h
> index 90bfa3279a01..9e5b4760e6c2 100644
> --- a/include/linux/rcuwait.h
> +++ b/include/linux/rcuwait.h
> @@ -44,7 +44,7 @@ extern void rcuwait_wake_up(struct rcuwait *w);
> */ \
> WARN_ON(current->exit_state); \
> \
> - rcu_assign_pointer((w)->task, current); \
> + WRITE_ONCE((w)->task, current); \
> for (;;) { \
> /* \
> * Implicit barrier (A) pairs with (B) in \
Distinct lack of justification for loosing the RELEASE again.
prev parent reply other threads:[~2019-02-21 9:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-21 5:49 [PATCH RFC 0/5] RCU fixes for rcu_assign_pointer() usage Joel Fernandes (Google)
2019-02-21 5:49 ` [PATCH RFC 1/5] net: rtnetlink: Fix incorrect RCU API usage Joel Fernandes (Google)
2019-02-21 5:49 ` [PATCH RFC 2/5] ixgbe: " Joel Fernandes (Google)
2019-02-21 5:49 ` [PATCH RFC 3/5] sched/cpufreq: " Joel Fernandes (Google)
2019-02-21 9:18 ` Peter Zijlstra
2019-02-21 15:21 ` Joel Fernandes
2019-02-21 15:31 ` Peter Zijlstra
2019-02-21 15:52 ` Paul E. McKenney
2019-02-21 16:11 ` Peter Zijlstra
2019-02-21 17:13 ` Joel Fernandes
2019-02-21 17:29 ` Paul E. McKenney
2019-02-21 16:17 ` Steven Rostedt
2019-02-21 23:05 ` Rafael J. Wysocki
2019-02-21 5:49 ` [PATCH RFC 4/5] sched/topology: Annonate RCU pointers properly Joel Fernandes (Google)
2019-02-21 9:19 ` Peter Zijlstra
2019-02-21 15:10 ` Joel Fernandes
2019-02-21 15:29 ` Peter Zijlstra
2019-02-21 17:17 ` Joel Fernandes
2019-02-21 5:49 ` [PATCH RFC 5/5] rcuwait: Replace rcu_assign_pointer() with WRITE_ONCE Joel Fernandes (Google)
2019-02-21 9:20 ` Peter Zijlstra [this message]
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