From: "Michael S. Tsirkin" <mst@redhat.com>
To: David Miller <davem@davemloft.net>
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
arnd@arndb.de, linux-arch@vger.kernel.org,
andrew.cooper3@citrix.com,
virtualization@lists.linux-foundation.org,
stefano.stabellini@eu.citrix.com
Subject: Re: [PATCH 00/34] arch: barrier cleanup + __smp_xxx barriers for virt
Date: Wed, 30 Dec 2015 23:36:29 +0200 [thread overview]
Message-ID: <20151230224855-mutt-send-email-mst@redhat.com> (raw)
In-Reply-To: <20151230.154646.596597479469584255.davem@davemloft.net>
On Wed, Dec 30, 2015 at 03:46:46PM -0500, David Miller wrote:
> From: "Michael S. Tsirkin" <mst@redhat.com>
> Date: Wed, 30 Dec 2015 14:58:19 +0200
>
> > -. Patch 1 documents the __smp APIs, and explains why they are
> > useful for virt
>
> If virt is doing things like interacting with descriptors that are
> shared with a (potentially SMP) host, why don't we just annotate those
> specific cases?
Using a bunch of per-arch ifdefs in virtio?
That's fundamentally what we have now.
But basically the rework reduces the LOC count in kernel anyway
by moving all ifdef CONFIG_SMP hacks into asm-generic.
So why not let virt benefit?
Or do you mean wrappers for __smp_XXX that explicitly
say they are for talking to host?
E.g. pv_mb() pv_rmb() etc.
That sounds very reasonable to me.
__smp_XXX things then become an implementation detail.
> The other memory barriers in the kernel do not matter for SMP'ness
> when build UP.
next prev parent reply other threads:[~2015-12-30 21:36 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-12-30 12:58 [PATCH 00/34] arch: barrier cleanup + __smp_xxx barriers for virt Michael S. Tsirkin
2015-12-30 12:58 ` Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 00/34] arch: barrier cleanup + __smp_XXX " Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 01/34] Documentation/memory-barriers.txt: document __smb_mb() Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2016-01-04 11:08 ` Stefano Stabellini
2016-01-04 11:08 ` Stefano Stabellini
2016-01-04 11:27 ` Michael S. Tsirkin
2016-01-04 11:27 ` Michael S. Tsirkin
2016-01-04 11:08 ` Stefano Stabellini
2015-12-30 13:24 ` [PATCH 02/34] asm-generic: guard smp_store_release/load_acquire Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 03/34] ia64: rename nop->iosapic_nop Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 16:39 ` Luck, Tony
2015-12-30 16:39 ` Luck, Tony
2015-12-30 13:24 ` [PATCH 04/34] ia64: reuse asm-generic/barrier.h Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 16:41 ` Luck, Tony
2015-12-30 16:41 ` Luck, Tony
2015-12-30 13:24 ` [PATCH 05/34] powerpc: " Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 06/34] s390: " Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 07/34] sparc: " Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 17:56 ` David Miller
2015-12-30 17:56 ` David Miller
2015-12-30 19:55 ` Michael S. Tsirkin
2015-12-30 19:55 ` Michael S. Tsirkin
2015-12-30 19:55 ` Michael S. Tsirkin
2015-12-30 20:47 ` David Miller
2015-12-30 20:47 ` David Miller
2015-12-30 20:47 ` David Miller
2015-12-30 17:56 ` David Miller
2015-12-30 13:24 ` [PATCH 08/34] asm-generic: smp_store_mb should use smp_mb Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:44 ` Arnd Bergmann
2015-12-30 13:44 ` Arnd Bergmann
2015-12-30 20:30 ` Michael S. Tsirkin
2015-12-30 20:30 ` Michael S. Tsirkin
2015-12-30 22:43 ` Arnd Bergmann
2015-12-30 22:43 ` Arnd Bergmann
2015-12-30 13:24 ` [PATCH 09/34] arm: reuse asm-generic/barrier.h Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` [PATCH 10/34] arm64: " Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:24 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 11/34] metag: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 12/34] mips: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 13/34] x86/um: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 14/34] x86: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 15/34] asm-generic: add __smp_XXX wrappers Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 15/34] asm-generic: add __smp_xxx wrappers Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 16/34] powerpc: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 16/34] powerpc: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 16/34] powerpc: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 17/34] arm64: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 17/34] arm64: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 17/34] arm64: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 18/34] arm: " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 18/34] arm: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 18/34] arm: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 19/34] blackfin: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 19/34] blackfin: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 20/34] ia64: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 20/34] ia64: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 16:43 ` [PATCH 20/34] ia64: define __smp_XXX Luck, Tony
2015-12-30 13:25 ` [PATCH 21/34] metag: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 21/34] metag: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 22/34] mips: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 22/34] mips: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 22/34] mips: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 23/34] s390: " Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 23/34] s390: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 24/34] sh: define __smp_XXX, fix smp_store_mb for !SMP Michael S. Tsirkin
2015-12-30 13:25 ` [PATCH 24/34] sh: define __smp_xxx, " Michael S. Tsirkin
2015-12-30 13:25 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 25/34] sparc: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 25/34] sparc: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 26/34] tile: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 26/34] tile: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 27/34] xtensa: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 27/34] xtensa: define __smp_xxx Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 28/34] x86: define __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 28/34] x86: define __smp_xxX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 29/34] Revert "virtio_ring: Update weak barriers to use dma_wmb/rmb" Michael S. Tsirkin
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 30/34] virtio_ring: update weak barriers to use __smp_XXX Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 31/34] xenbus: use __smp_XXX barriers Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 31/34] xenbus: use __smp_xxx barriers Michael S. Tsirkin
2016-01-04 11:58 ` [PATCH 31/34] xenbus: use __smp_XXX barriers Stefano Stabellini
2016-01-04 11:58 ` Stefano Stabellini
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 32/34] xen/io: " Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 32/34] xen/io: use __smp_xxx barriers Michael S. Tsirkin
2016-01-04 11:59 ` [PATCH 32/34] xen/io: use __smp_XXX barriers Stefano Stabellini
2016-01-04 11:59 ` Stefano Stabellini
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 33/34] virtio: use __smp_load_acquire/__smp_store_release Michael S. Tsirkin
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:26 ` [PATCH 34/34] virtio_ring: use __smp_store_mb Michael S. Tsirkin
2015-12-30 13:26 ` Michael S. Tsirkin
2015-12-30 13:49 ` [PATCH 00/34] arch: barrier cleanup + __smp_XXX barriers for virt Arnd Bergmann
2015-12-30 21:45 ` [PATCH 00/34] arch: barrier cleanup + __smp_xxx " Michael S. Tsirkin
2015-12-30 22:45 ` Arnd Bergmann
2015-12-30 22:45 ` Arnd Bergmann
2015-12-30 21:45 ` Michael S. Tsirkin
2015-12-30 20:46 ` David Miller
2015-12-30 20:46 ` David Miller
2015-12-30 21:36 ` Michael S. Tsirkin [this message]
2015-12-30 21:59 ` David Miller
2015-12-30 21:59 ` David Miller
2015-12-30 21:36 ` Michael S. Tsirkin
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