[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianne
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness() |
Date: |
Thu, 27 Aug 2015 11:49:32 +0100 |
On 27 August 2015 at 05:50, Jason Wang <address@hidden> wrote:
> On 08/26/2015 10:51 PM, Greg Kurz wrote:
>> On Wed, 26 Aug 2015 15:21:59 +0100
>> Peter Maydell <address@hidden> wrote:
>>> This seems to me like a bug in the caller. Why would anything
>>> try to call into the memory subsystem to do a zero-size
>>> transaction?
>> Here's the patch which needs zero-size eventfd:
>>
>> http://patchwork.ozlabs.org/patch/509428/
> Yes, this is because we want to use wildcard mmio eventfd (which
> requires size to be zero) to speed up virtio 1.0 mmio.
But *why* does it require the size to be zero? I still think
the caller should just avoid trying to do zero-size memory
operations: they don't make sense. What is a zero size
operation supposed to mean?
-- PMM
- [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Jason Wang, 2015/08/26
- [Qemu-devel] [PATCH 2/2] pci: test-dev: try to test fast mmio bus for wildcard mmio event, Jason Wang, 2015/08/26
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Peter Maydell, 2015/08/26
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Greg Kurz, 2015/08/26
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Jason Wang, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(),
Peter Maydell <=
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Michael S. Tsirkin, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Peter Maydell, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Michael S. Tsirkin, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Peter Maydell, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Michael S. Tsirkin, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Peter Maydell, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Michael S. Tsirkin, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Peter Maydell, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Michael S. Tsirkin, 2015/08/27
- Re: [Qemu-devel] [PATCH 1/2] memory: allow zero size for adjust_endianness(), Greg Kurz, 2015/08/27