From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
qemu-devel@nongnu.org, David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH 13/13] iommu: Add a memory barrier to DMA RW function
Date: Thu, 17 May 2012 07:12:40 +1000 [thread overview]
Message-ID: <1337202760.30558.15.camel@pasglop> (raw)
In-Reply-To: <1337202645.30558.13.camel@pasglop>
On Thu, 2012-05-17 at 07:10 +1000, Benjamin Herrenschmidt wrote:
> I have a long experience with dealing with ordering issues on large SMP
> systems and believe me, anything "fine grained" is really really hard to
> generally get right, and the resulting bugs are really nasty to track
> down and even identify. So I have a strong bias toward the big hammer
> approach that is guaranteed to avoid the problem for anything using the
> right DMA accessors.
BTW, this is going to also hurt SMP ARMs ... ARM is getting increasingly
out of order as well.
Cheers,
Ben.
next prev parent reply other threads:[~2012-05-16 21:12 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-05-10 4:48 [Qemu-devel] [PATCH 00/13] IOMMU infrastructure Benjamin Herrenschmidt
2012-05-10 4:48 ` [Qemu-devel] [PATCH 01/13] Better support for dma_addr_t variables Benjamin Herrenschmidt
2012-05-10 4:48 ` [Qemu-devel] [PATCH 02/13] Implement cpu_physical_memory_zero() Benjamin Herrenschmidt
2012-05-15 0:42 ` Anthony Liguori
2012-05-15 1:23 ` David Gibson
2012-05-15 2:03 ` Anthony Liguori
2012-05-10 4:48 ` [Qemu-devel] [PATCH 03/13] iommu: Add universal DMA helper functions Benjamin Herrenschmidt
2012-05-10 4:48 ` [Qemu-devel] [PATCH 04/13] usb-ohci: Use " Benjamin Herrenschmidt
2012-05-10 4:48 ` [Qemu-devel] [PATCH 05/13] iommu: Make sglists and dma_bdrv helpers use new universal DMA helpers Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 06/13] ide/ahci: Use universal DMA helper functions Benjamin Herrenschmidt
2012-05-21 1:51 ` [Qemu-devel] [PATCH 06/13 - UPDATED] " Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 07/13] usb: Convert usb_packet_{map, unmap} to universal DMA helpers Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 08/13] iommu: Introduce IOMMU emulation infrastructure Benjamin Herrenschmidt
2012-05-15 0:49 ` Anthony Liguori
2012-05-15 1:42 ` David Gibson
2012-05-15 2:03 ` Anthony Liguori
2012-05-15 2:32 ` Benjamin Herrenschmidt
2012-05-15 2:50 ` Anthony Liguori
2012-05-15 3:02 ` Benjamin Herrenschmidt
2012-05-15 14:02 ` Anthony Liguori
2012-05-15 21:55 ` Benjamin Herrenschmidt
2012-05-15 22:02 ` Anthony Liguori
2012-05-15 23:08 ` Benjamin Herrenschmidt
2012-05-15 23:58 ` Anthony Liguori
2012-05-16 0:41 ` Benjamin Herrenschmidt
2012-05-16 0:54 ` Anthony Liguori
2012-05-16 1:20 ` Benjamin Herrenschmidt
2012-05-16 19:36 ` Anthony Liguori
2012-05-10 4:49 ` [Qemu-devel] [PATCH 09/13] iommu: Add facility to cancel in-use dma memory maps Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 10/13] pseries: Convert sPAPR TCEs to use generic IOMMU infrastructure Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 11/13] iommu: Allow PCI to use " Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 12/13] pseries: Implement IOMMU and DMA for PAPR PCI devices Benjamin Herrenschmidt
2012-05-10 4:49 ` [Qemu-devel] [PATCH 13/13] iommu: Add a memory barrier to DMA RW function Benjamin Herrenschmidt
2012-05-15 0:52 ` Anthony Liguori
2012-05-15 1:11 ` Benjamin Herrenschmidt
2012-05-15 1:44 ` David Gibson
2012-05-16 4:35 ` Benjamin Herrenschmidt
2012-05-16 5:51 ` David Gibson
2012-05-16 19:39 ` Anthony Liguori
2012-05-16 21:10 ` Benjamin Herrenschmidt
2012-05-16 21:12 ` Benjamin Herrenschmidt [this message]
2012-05-17 0:07 ` Benjamin Herrenschmidt
2012-05-17 0:24 ` Benjamin Herrenschmidt
2012-05-17 0:52 ` [Qemu-devel] [RFC/PATCH] Add a memory barrier to guest memory access functions Benjamin Herrenschmidt
2012-05-17 2:28 ` Anthony Liguori
2012-05-17 2:44 ` Benjamin Herrenschmidt
2012-05-17 22:09 ` Anthony Liguori
2012-05-18 1:04 ` David Gibson
2012-05-18 1:16 ` Benjamin Herrenschmidt
2012-05-17 3:35 ` David Gibson
2012-05-18 6:53 ` [Qemu-devel] [PATCH 13/13] iommu: Add a memory barrier to DMA RW function Paolo Bonzini
2012-05-18 8:18 ` Benjamin Herrenschmidt
2012-05-18 8:57 ` Paolo Bonzini
2012-05-18 22:26 ` Benjamin Herrenschmidt
2012-05-19 7:24 ` Paolo Bonzini
2012-05-20 21:36 ` Benjamin Herrenschmidt
2012-05-21 1:56 ` [Qemu-devel] [PATCH] Add a memory barrier to guest memory access functions Benjamin Herrenschmidt
2012-05-21 8:11 ` Paolo Bonzini
2012-05-21 8:31 ` Michael S. Tsirkin
2012-05-21 8:58 ` Benjamin Herrenschmidt
2012-05-21 9:07 ` Benjamin Herrenschmidt
2012-05-21 9:16 ` Benjamin Herrenschmidt
2012-05-21 9:34 ` Michael S. Tsirkin
2012-05-21 9:53 ` Benjamin Herrenschmidt
2012-05-21 10:31 ` Michael S. Tsirkin
2012-05-21 11:45 ` Benjamin Herrenschmidt
2012-05-21 12:18 ` Michael S. Tsirkin
2012-05-21 15:16 ` Paolo Bonzini
2012-05-21 21:58 ` [Qemu-devel] [PATCH] Add a memory barrier to guest memory access function Benjamin Herrenschmidt
2012-05-21 22:22 ` Michael S. Tsirkin
2012-05-21 22:56 ` Benjamin Herrenschmidt
2012-05-22 5:11 ` Michael S. Tsirkin
2012-05-22 0:00 ` Benjamin Herrenschmidt
2012-05-22 4:19 ` Rusty Russell
2012-05-21 22:18 ` [Qemu-devel] [PATCH] Add a memory barrier to guest memory access functions Anthony Liguori
2012-05-21 22:26 ` Benjamin Herrenschmidt
2012-05-21 22:31 ` Anthony Liguori
2012-05-21 22:44 ` Michael S. Tsirkin
2012-05-21 23:02 ` Benjamin Herrenschmidt
2012-05-22 4:34 ` [Qemu-devel] [PATCH] Add a memory barrier to DMA functions Benjamin Herrenschmidt
2012-05-22 4:51 ` Benjamin Herrenschmidt
2012-05-22 7:17 ` Benjamin Herrenschmidt
2012-05-22 11:14 ` Michael S. Tsirkin
2012-05-22 11:41 ` Benjamin Herrenschmidt
2012-05-22 12:03 ` Michael S. Tsirkin
2012-05-22 21:24 ` Benjamin Herrenschmidt
2012-05-22 21:40 ` Anthony Liguori
2012-05-21 22:37 ` [Qemu-devel] [PATCH] Add a memory barrier to guest memory access functions Michael S. Tsirkin
2012-05-15 0:52 ` [Qemu-devel] [PATCH 00/13] IOMMU infrastructure Anthony Liguori
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