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Re: [Qemu-devel] [PATCH 0/9] target-ppc: Rudimentary Support for Transac
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] [PATCH 0/9] target-ppc: Rudimentary Support for Transactional Memory |
Date: |
Thu, 18 Dec 2014 23:52:16 +0100 |
User-agent: |
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.3.0 |
On 18.12.14 17:34, Tom Musta wrote:
> This patch series introduces rudimentary support for the Transactional Memory
> (TM) feature of Power ISA V2.07. In a nutshell, software uses the feature by
> initiating a transaction via the tbegin instruction. Hardware then
> accumulates
> storage accesses until the transaction is committed via the tend
> instruction).
> At this point, either the instruction completes and all storage accesses are
> atomic with respect to other processors; or the transaction fails and
> processor
> state reverts to the point of tbegin. Transaction success or failure is
> recorded
> in CR[0] and the instruction immediately following tbegin is expected to
> inspect
> this field and provide an error path to properly handle failure.
>
> Accurately emulating such a feature in QEMU is quite difficult. Instead, the
> approach taken here simply fails the transaction at the point of tbegin and
> thus immediately takes software down the error handlling path. As such, this
> can
> be considered a toleration mode for any software that utilizes the TM feature.
> Valgrind has taken a similar approach. There are no immediate plans to
> implement
> a more sophisticated model.
>
> Currently, Power8 is the only Power processor that supports TM.
Thanks, applied all to ppc-next.
Alex
- Re: [Qemu-devel] [PATCH 5/9] target-ppc: Introduce TEXASRU Bit Fields, (continued)
[Qemu-devel] [PATCH 6/9] target-ppc: Introduce tbegin, Tom Musta, 2014/12/18
[Qemu-devel] [PATCH 7/9] target-ppc: Introduce TM Noops, Tom Musta, 2014/12/18
[Qemu-devel] [PATCH 8/9] target-ppc: Introduce tcheck, Tom Musta, 2014/12/18
[Qemu-devel] [PATCH 9/9] target-ppc: Introduce Privileged TM Noops, Tom Musta, 2014/12/18
Re: [Qemu-devel] [PATCH 0/9] target-ppc: Rudimentary Support for Transactional Memory,
Alexander Graf <=