From: David Vrabel <david.vrabel@citrix.com>
To: "Michael S. Tsirkin" <mst@redhat.com>, linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org,
linux-sh@vger.kernel.org, Peter Zijlstra <peterz@infradead.org>,
virtualization@lists.linux-foundation.org,
"H. Peter Anvin" <hpa@zytor.com>,
sparclinux@vger.kernel.org,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
linux-arch@vger.kernel.org, linux-s390@vger.kernel.org,
Arnd Bergmann <arnd@arndb.de>,
x86@kernel.org, xen-devel@lists.xenproject.org,
Ingo Molnar <mingo@elte.hu>,
linux-xtensa@linux-xtensa.org,
user-mode-linux-devel@lists.sourceforge.net,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
adi-buildroot-devel@lists.sourceforge.net,
Thomas Gleixner <tglx@linutronix.de>,
linux-metag@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
Andrew Cooper <andrew.cooper3@citrix.com>,
David Vrabel <david.vrabel@citrix.com>,
linuxppc-dev@lists.ozlabs.org, David Miller <davem@d>
Subject: Re: [Xen-devel] [PATCH v2 33/34] xenbus: use virt_xxx barriers
Date: Mon, 04 Jan 2016 11:32:00 +0000 [thread overview]
Message-ID: <568A5830.9000501@citrix.com> (raw)
In-Reply-To: <1451572003-2440-34-git-send-email-mst@redhat.com>
On 31/12/15 19:10, Michael S. Tsirkin wrote:
> drivers/xen/xenbus/xenbus_comms.c uses
> full memory barriers to communicate with the other side.
>
> For guests compiled with CONFIG_SMP, smp_wmb and smp_mb
> would be sufficient, so mb() and wmb() here are only needed if
> a non-SMP guest runs on an SMP host.
>
> Switch to virt_xxx barriers which serve this exact purpose.
Acked-by: David Vrabel <david.vrabel@citrix.com>
If you're feeling particularly keen there's a rmb() consume_one_event()
in drivers/xen/events/events_fifo.c that can be converted to virt_rmb()
as well.
David
next prev parent reply other threads:[~2016-01-04 11:32 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-31 19:05 [PATCH v2 00/34] arch: barrier cleanup + barriers for virt Michael S. Tsirkin
2015-12-31 19:05 ` [PATCH v2 01/32] lcoking/barriers, arch: Use smp barriers in smp_store_release() Michael S. Tsirkin
2015-12-31 19:05 ` [PATCH v2 02/32] asm-generic: guard smp_store_release/load_acquire Michael S. Tsirkin
2015-12-31 19:06 ` [PATCH v2 03/32] ia64: rename nop->iosapic_nop Michael S. Tsirkin
2015-12-31 19:06 ` [PATCH v2 04/32] ia64: reuse asm-generic/barrier.h Michael S. Tsirkin
2015-12-31 19:06 ` [PATCH v2 05/32] powerpc: " Michael S. Tsirkin
2015-12-31 19:06 ` [PATCH v2 06/32] s390: " Michael S. Tsirkin
2016-01-04 13:20 ` Peter Zijlstra
2016-01-04 15:03 ` Martin Schwidefsky
2016-01-04 20:42 ` Michael S. Tsirkin
2016-01-05 8:03 ` Martin Schwidefsky
2016-01-04 20:34 ` Michael S. Tsirkin
2015-12-31 19:06 ` [PATCH v2 07/32] sparc: " Michael S. Tsirkin
2015-12-31 19:43 ` David Miller
2015-12-31 19:06 ` [PATCH v2 08/32] arm: " Michael S. Tsirkin
2016-01-02 11:20 ` Russell King - ARM Linux
2015-12-31 19:06 ` [PATCH v2 09/32] arm64: " Michael S. Tsirkin
[not found] ` <1451572003-2440-1-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2015-12-31 19:07 ` [PATCH v2 10/32] metag: " Michael S. Tsirkin
2016-01-04 23:24 ` James Hogan
2015-12-31 19:07 ` [PATCH v2 12/32] x86/um: " Michael S. Tsirkin
[not found] ` <1451572003-2440-13-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-01-05 23:12 ` Richard Weinberger
2015-12-31 19:07 ` [PATCH v2 14/32] asm-generic: add __smp_xxx wrappers Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 20/32] metag: define __smp_xxx Michael S. Tsirkin
2016-01-04 13:41 ` Peter Zijlstra
2016-01-04 15:25 ` James Hogan
2016-01-04 15:30 ` Peter Zijlstra
2016-01-04 16:04 ` James Hogan
2016-01-05 0:09 ` James Hogan
[not found] ` <20160105000929.GM17861-4bYivNCBEGTR3KXKvIWQxtm+Uo4AYnCiHZ5vskTnxNA@public.gmane.org>
2016-01-11 11:10 ` Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 27/32] x86: " Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 31/32] sh: support a 2-byte smp_store_mb Michael S. Tsirkin
2016-01-04 14:05 ` Peter Zijlstra
2016-01-05 23:27 ` Rich Felker
2016-01-06 11:19 ` Michael S. Tsirkin
2016-01-06 11:40 ` Peter Zijlstra
2016-01-06 11:52 ` Michael S. Tsirkin
2016-01-06 14:32 ` Peter Zijlstra
2016-01-06 15:42 ` Rob Landley
2016-01-06 16:57 ` Peter Zijlstra
2016-01-06 20:21 ` Rob Landley
2016-01-06 18:57 ` Geert Uytterhoeven
2016-01-06 18:23 ` Rich Felker
2016-01-06 20:23 ` Michael S. Tsirkin
2016-01-06 23:53 ` Rich Felker
2016-01-07 13:37 ` Peter Zijlstra
2016-01-07 19:05 ` Rich Felker
2016-01-07 15:50 ` Michael S. Tsirkin
2016-01-07 17:48 ` Michael S. Tsirkin
2016-01-07 19:10 ` Rich Felker
2016-01-07 22:41 ` Michael S. Tsirkin
2016-01-08 4:25 ` Rich Felker
2016-01-08 7:23 ` Michael S. Tsirkin
2016-01-06 22:14 ` Michael S. Tsirkin
2015-12-31 19:10 ` [PATCH v2 33/34] xenbus: use virt_xxx barriers Michael S. Tsirkin
2016-01-04 11:32 ` David Vrabel [this message]
2016-01-04 12:03 ` Stefano Stabellini
[not found] ` <1451572003-2440-34-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-01-04 14:09 ` Peter Zijlstra
2015-12-31 19:07 ` [PATCH v2 11/32] mips: reuse asm-generic/barrier.h Michael S. Tsirkin
[not found] ` <1451572003-2440-12-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-01-04 13:26 ` Peter Zijlstra
2015-12-31 19:07 ` [PATCH v2 13/32] x86: " Michael S. Tsirkin
2015-12-31 19:07 ` [PATCH v2 15/32] powerpc: define __smp_xxx Michael S. Tsirkin
2016-01-05 1:36 ` Boqun Feng
[not found] ` <20160105013648.GA1256-nNqVUaWX1rAq6Sbylg4iGasjOiXwFzmk@public.gmane.org>
2016-01-05 8:51 ` Michael S. Tsirkin
2016-01-05 9:53 ` Boqun Feng
[not found] ` <20160105095341.GA5321-nNqVUaWX1rAq6Sbylg4iGasjOiXwFzmk@public.gmane.org>
2016-01-05 16:16 ` Michael S. Tsirkin
2016-01-06 1:51 ` Boqun Feng
[not found] ` <20160106015152.GA14605-nNqVUaWX1rAq6Sbylg4iGasjOiXwFzmk@public.gmane.org>
2016-01-06 20:23 ` Michael S. Tsirkin
2016-01-07 0:43 ` Boqun Feng
2015-12-31 19:07 ` [PATCH v2 16/32] arm64: " Michael S. Tsirkin
2015-12-31 19:07 ` [PATCH v2 17/32] arm: " Michael S. Tsirkin
2016-01-02 11:24 ` Russell King - ARM Linux
2016-01-03 9:12 ` Michael S. Tsirkin
2016-01-04 13:36 ` Peter Zijlstra
2016-01-04 13:54 ` Peter Zijlstra
2016-01-04 13:59 ` Russell King - ARM Linux
2016-01-05 14:38 ` Michael S. Tsirkin
2016-01-04 20:39 ` Michael S. Tsirkin
2016-01-04 20:12 ` Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 18/32] blackfin: " Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 19/32] ia64: " Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 21/32] mips: " Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 22/32] s390: " Michael S. Tsirkin
2016-01-04 13:45 ` Peter Zijlstra
2016-01-04 20:18 ` Michael S. Tsirkin
2016-01-05 8:13 ` Martin Schwidefsky
2016-01-05 9:30 ` Michael S. Tsirkin
2016-01-05 12:08 ` Martin Schwidefsky
2016-01-05 13:04 ` Michael S. Tsirkin
2016-01-05 14:21 ` Martin Schwidefsky
[not found] ` <20160105105335-mutt-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-01-05 15:39 ` Christian Borntraeger
2016-01-05 16:04 ` Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 23/32] sh: define __smp_xxx, fix smp_store_mb for !SMP Michael S. Tsirkin
2015-12-31 19:08 ` [PATCH v2 24/32] sparc: define __smp_xxx Michael S. Tsirkin
2015-12-31 19:44 ` David Miller
2015-12-31 19:09 ` [PATCH v2 25/32] tile: " Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 26/32] xtensa: " Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 28/32] asm-generic: implement virt_xxx memory barriers Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 29/32] Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" Michael S. Tsirkin
2015-12-31 19:09 ` [PATCH v2 32/32] virtio_ring: use virt_store_mb Michael S. Tsirkin
2016-01-01 17:23 ` Sergei Shtylyov
[not found] ` <5686B622.6070600-M4DtvfQ/ZS1MRgGoP+s0PdBPR1lH4CV8@public.gmane.org>
2016-01-03 9:01 ` Michael S. Tsirkin
2015-12-31 19:10 ` [PATCH v2 34/34] xen/io: use virt_xxx barriers Michael S. Tsirkin
2016-01-04 11:32 ` [Xen-devel] " David Vrabel
[not found] ` <1451572003-2440-35-git-send-email-mst-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2016-01-04 12:05 ` Stefano Stabellini
2016-01-01 9:39 ` [PATCH v2 30/32] virtio_ring: update weak barriers to use __smp_xxx Michael S. Tsirkin
2016-01-01 10:21 ` Michael S. Tsirkin
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