From: "K. Y. Srinivasan" <kys@microsoft.com>
To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com,
vkuznets@redhat.com, jasowang@redhat.com
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Subject: [PATCH 4/8] Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
Date: Fri, 26 Feb 2016 15:13:18 -0800 [thread overview]
Message-ID: <1456528402-21982-4-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1456528402-21982-1-git-send-email-kys@microsoft.com>
From: Vitaly Kuznetsov <vkuznets@redhat.com>
Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.
Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/hv/channel_mgmt.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 73a17be..38b682ba 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -605,7 +605,7 @@ static void vmbus_wait_for_unload(void)
bool unloaded = false;
while (1) {
- if (msg->header.message_type == HVMSG_NONE) {
+ if (READ_ONCE(msg->header.message_type) == HVMSG_NONE) {
mdelay(10);
continue;
}
--
1.7.4.1
next prev parent reply other threads:[~2016-02-26 21:35 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-26 23:13 [PATCH 0/8] Drivers: hv: Miscellaneous fixes K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 1/8] Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 2/8] Drivers: hv: vmbus: avoid wait_for_completion() on crash K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 3/8] Drivers: hv: vmbus: remove code duplication in message handling K. Y. Srinivasan
2016-02-26 23:13 ` K. Y. Srinivasan [this message]
2016-02-26 23:13 ` [PATCH 5/8] Drivers: hv: util: Pass the channel information during the init call K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 6/8] Drivers: hv: utils: Remove util transport handler from list if registration fails K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 7/8] Drivers: hv: vmbus: Support handling messages on multiple CPUs K. Y. Srinivasan
2016-02-26 23:13 ` [PATCH 8/8] Drivers: hv: vmbus: Support kexec on ws2012 r2 and above K. Y. Srinivasan
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