Re: [PATCH v3 0/4] optimize memory hotplug

From: Ingo Molnar
Date: Wed Feb 14 2018 - 03:09:40 EST



* Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:

> On Tue, 13 Feb 2018 14:31:55 -0500 Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> wrote:
>
> > This patchset:
> > - Improves hotplug performance by eliminating a number of
> > struct page traverses during memory hotplug.
> >
> > - Fixes some issues with hotplugging, where boundaries
> > were not properly checked. And on x86 block size was not properly aligned
> > with end of memory
> >
> > - Also, potentially improves boot performance by eliminating condition from
> > __init_single_page().
> >
> > - Adds robustness by verifying that that struct pages are correctly
> > poisoned when flags are accessed.
>
> I'm now attempting to get a 100% review rate on MM patches, which is
> why I started adding my Reviewed-by: when I do that thing.
>
> I'm not familiar enough with this code to add my own Reviewed-by:, and
> we'll need to figure out what to do in such cases. I shall be sending
> out periodic review-status summaries.
>
> If you're able to identify a suitable reviewer for this work and to
> offer them beer, that would help. Let's see what happens as the weeks
> unfold.

The largest patch, fix patch #2, looks good to me and fixes a real bug.
Patch #1 and #3 also look good to me (assuming the runtime overhead
added by patch #3 is OK to you):

Reviewed-by: Ingo Molnar <mingo@xxxxxxxxxx>

(I suspect patch #1 and patch #2 should also get a Cc: stable.)

Patch #4 is too large to review IMO: it should be split up into as many patches as
practically possible. That will also help bisectability, should anything break.

Before applying these patches please fix changelog and code comment spelling.

But it's all good stuff AFAICS!

Thanks,

Ingo