Re: [PATCH] use fallocate to create table

[Sergei Golubchik]

Hi, Sveta!

On Dec 27, Sveta Smirnova wrote:
> Dear Toshikuni,
> 
> >> I made a patch for MySQL 5.5.28 to speed up InnoDB table space
> >> creation.  I noticed that there are slow I/Os (consisting of many
> >> zero-fill writes and syncs) when creating tables.
> >>
> >> Linux kernels have the fallocate(2) system call, which guarantees
> >> that a given file region is zeroed and yields a performance
> >> improvement on supporting file systems.
> >>
> >> I measured a 10% speed up in table space creation in our
> >> application.
> >>
> >> Could you please accept my patch? If there is anything further I
> >> should do for this patch, please advise me.
> 
> We evaluated this option internally and, unfortunately, results were not 
> conclusive, so we decided not to implement the patch.

And why is that? What were the opinions? What were the arguments against
this patch?

Regards,
Sergei