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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 6/9] Drivers: hv: ring_buffer: remove stray smp_read_barrier_depends()
Date: Mon, 14 Dec 2015 19:01:58 -0800	[thread overview]
Message-ID: <1450148521-28447-6-git-send-email-kys@microsoft.com> (raw)
In-Reply-To: <1450148521-28447-1-git-send-email-kys@microsoft.com>

From: Vitaly Kuznetsov <vkuznets@redhat.com>

smp_read_barrier_depends() does nothing on almost all arcitectures
including x86 and having it in the beginning of
hv_get_ringbuffer_availbytes() does not provide any guarantees anyway.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 include/linux/hyperv.h |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index acd995b..179ff33 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -141,8 +141,6 @@ hv_get_ringbuffer_availbytes(struct hv_ring_buffer_info *rbi,
 {
 	u32 read_loc, write_loc, dsize;
 
-	smp_read_barrier_depends();
-
 	/* Capture the read/write indices before they changed */
 	read_loc = rbi->ring_buffer->read_index;
 	write_loc = rbi->ring_buffer->write_index;
-- 
1.7.4.1


  parent reply	other threads:[~2015-12-15  1:29 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-15  3:00 [PATCH 0/9] Drivers: hv: Cleanup ringbuffer code K. Y. Srinivasan
2015-12-15  3:01 ` [PATCH 1/9] Drivers: hv: utils: fix memory leak on on_msg() failure K. Y. Srinivasan
2015-12-15  3:01   ` [PATCH 2/9] Drivers: hv: utils: rename outmsg_lock K. Y. Srinivasan
2015-12-15  3:01   ` [PATCH 3/9] Drivers: hv: utils: introduce HVUTIL_TRANSPORT_DESTROY mode K. Y. Srinivasan
2015-12-15 12:14     ` Dexuan Cui
2015-12-15 17:10       ` Vitaly Kuznetsov
2015-12-15  3:01   ` [PATCH 4/9] Drivers: hv: utils: fix crash when device is removed from host side K. Y. Srinivasan
2015-12-15  3:01   ` [PATCH 5/9] Drivers: hv: ring_buffer.c: fix comment style K. Y. Srinivasan
2015-12-15  3:01   ` K. Y. Srinivasan [this message]
2015-12-15  3:01   ` [PATCH 7/9] Drivers: hv: ring_buffer: remove code duplication from hv_ringbuffer_peek/read() K. Y. Srinivasan
2015-12-15  3:02   ` [PATCH 8/9] Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw() K. Y. Srinivasan
2015-12-15  3:02   ` [PATCH 9/9] Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek() K. Y. Srinivasan

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