Re: Substituting Checksum Algorithm (was: Enabling Checksums) - Mailing list pgsql-hackers

From Simon Riggs
Subject Re: Substituting Checksum Algorithm (was: Enabling Checksums)
Date
Msg-id CA+U5nM+vAdcY3DK=spV04NmYNTq6XRXMbjie9mYrrT4MpP8svA@mail.gmail.com
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In response to Re: Substituting Checksum Algorithm (was: Enabling Checksums)  (Ants Aasma <ants@cybertec.at>)
List pgsql-hackers
On 30 April 2013 12:23, Ants Aasma <ants@cybertec.at> wrote:

>> ISTM that we also need this patch to put memory barriers in place
>> otherwise the code might be rearranged.
>
> The compiler and CPU both have to preserve correctness when
> rearranging code, so I don't think we care about it here. It might
> matter if these routine could be called concurrently by multiple
> backends for a single buffer, but in that case memory barriers won't
> be enough, we'd need full exclusion.

Certainly happy not to commit anything else...

Thanks to Ants and Andres.

--Simon Riggs                   http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training & Services



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