Re: [PATCH 2/2] powerpc/mm: Enable page parallel initialisation
From: Michael Ellerman
Date: Tue Mar 08 2016 - 04:36:50 EST
On Tue, 2016-03-08 at 11:55 +0800, Li Zhang wrote:
> From: Li Zhang <zhlcindy@xxxxxxxxxxxxxxxxxx>
> Parallel initialisation has been enabled for X86, boot time is
> improved greatly. On Power8, it is improved greatly for small
> memory. Here is the result from my test on Power8 platform:
> For 4GB memory: 57% is improved, boot time as the following:
> with patch: 10s, without patch: 24.5s
This isn't worded quite right, and the numbers are a bit off.
old = 24.5
new = 10
So the improvement is 14.5 (seconds).
That means the improvement (14.5) as a percentage of the original boot time is:
= 14.5 / 24.5 * 100
So you would say:
For 4GB of memory, boot time is improved by 59%, from 24.5s to 10s.
> For 50GB memory: 22% is improved, boot time as the following:
> with patch: 43.8s, without patch: 56.8s
For 50GB memory, boot time is improved by 22%, from 56.8s to 43.8s.
> Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Li Zhang <zhlcindy@xxxxxxxxxxxxxxxxxx>
> * Add boot time details in change log.
> * Please apply this patch after [PATCH 1/2] mm: meminit: initialise
> more memory for inode/dentry hash tables in early boot, because
> [PATCH 1/2] is to fix a bug which can be reproduced on Power.
Given that, I think it would be best if Andrew merged both of these patches.
Because this patch is pretty trivial, whereas the patch to mm/ is less so.
Is that OK Andrew?
For this one:
Acked-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>