From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org
Cc: Juergen Gross <jgross@suse.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Stefano Stabellini <sstabellini@kernel.org>
Subject: [PATCH 7/7] xen/evtchn: read producer index only once
Date: Sat, 6 Feb 2021 11:49:32 +0100 [thread overview]
Message-ID: <20210206104932.29064-8-jgross@suse.com> (raw)
In-Reply-To: <20210206104932.29064-1-jgross@suse.com>
In evtchn_read() use READ_ONCE() for reading the producer index in
order to avoid the compiler generating multiple accesses.
Signed-off-by: Juergen Gross <jgross@suse.com>
---
drivers/xen/evtchn.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c
index 421382c73d88..f6b199b597bf 100644
--- a/drivers/xen/evtchn.c
+++ b/drivers/xen/evtchn.c
@@ -211,7 +211,7 @@ static ssize_t evtchn_read(struct file *file, char __user *buf,
goto unlock_out;
c = u->ring_cons;
- p = u->ring_prod;
+ p = READ_ONCE(u->ring_prod);
if (c != p)
break;
--
2.26.2
next prev parent reply other threads:[~2021-02-06 10:53 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-06 10:49 [PATCH 0/7] xen/events: bug fixes and some diagnostic aids Juergen Gross
2021-02-06 10:49 ` [PATCH 1/7] xen/events: reset affinity of 2-level event initially Juergen Gross
2021-02-06 11:20 ` Julien Grall
2021-02-06 12:09 ` Jürgen Groß
2021-02-06 12:19 ` Julien Grall
2021-02-06 10:49 ` [PATCH 2/7] xen/events: don't unmask an event channel when an eoi is pending Juergen Gross
2021-02-08 10:06 ` Jan Beulich
2021-02-08 10:21 ` Jürgen Groß
2021-02-08 10:15 ` Ross Lagerwall
2021-02-06 10:49 ` [PATCH 3/7] xen/events: fix lateeoi irq acknowledgment Juergen Gross
2021-02-06 10:49 ` [PATCH 4/7] xen/events: link interdomain events to associated xenbus device Juergen Gross
2021-02-08 23:26 ` Boris Ostrovsky
2021-02-09 13:55 ` Wei Liu
2021-02-06 10:49 ` [PATCH 5/7] xen/events: add per-xenbus device event statistics and settings Juergen Gross
2021-02-08 23:35 ` Boris Ostrovsky
2021-02-06 10:49 ` [PATCH 6/7] xen/evtch: use smp barriers for user event ring Juergen Gross
2021-02-08 9:38 ` Jan Beulich
2021-02-08 9:41 ` Jürgen Groß
2021-02-08 9:44 ` Andrew Cooper
2021-02-08 9:50 ` Jan Beulich
2021-02-08 10:23 ` Andrew Cooper
2021-02-08 10:25 ` Jürgen Groß
2021-02-08 10:31 ` Andrew Cooper
2021-02-08 10:36 ` Jan Beulich
2021-02-08 10:45 ` Andrew Cooper
2021-02-06 10:49 ` Juergen Gross [this message]
2021-02-08 9:48 ` [PATCH 7/7] xen/evtchn: read producer index only once Jan Beulich
2021-02-08 10:41 ` Jürgen Groß
2021-02-08 10:51 ` Jan Beulich
2021-02-08 10:59 ` Jürgen Groß
2021-02-08 11:50 ` Julien Grall
2021-02-08 11:54 ` Jan Beulich
2021-02-08 12:15 ` Jürgen Groß
2021-02-08 12:23 ` Jan Beulich
2021-02-08 12:26 ` Jürgen Groß
2021-02-08 11:40 ` Julien Grall
2021-02-08 11:48 ` Jürgen Groß
2021-02-08 12:03 ` Julien Grall
2021-02-06 18:46 ` [PATCH 0/7] xen/events: bug fixes and some diagnostic aids Julien Grall
2021-02-07 12:58 ` Jürgen Groß
2021-02-08 9:11 ` Julien Grall
2021-02-08 9:41 ` Jürgen Groß
2021-02-08 9:54 ` Julien Grall
2021-02-08 10:22 ` Jürgen Groß
2021-02-08 10:40 ` Julien Grall
2021-02-08 12:14 ` Jürgen Groß
2021-02-08 12:16 ` Julien Grall
2021-02-08 12:31 ` Jürgen Groß
2021-02-08 13:09 ` Julien Grall
2021-02-08 13:58 ` Jürgen Groß
2021-02-08 14:20 ` Julien Grall
2021-02-08 14:35 ` Julien Grall
2021-02-08 14:50 ` Jürgen Groß
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