Re: [PATCH] mm: skip if required_kernelcore is larger than totalpages

[Tang Chen]

On 10/14/2015 11:28 AM, Xishi Qiu wrote:
> On 2015/10/14 10:50, Tang Chen wrote:
>
> > Hi, Qiu
> >
> > The patch seems OK to me. Only one little concern below.
> >
> > On 10/12/2015 09:37 AM, Xishi Qiu wrote:
> > > On 2015/10/9 23:41, Yasuaki Ishimatsu wrote:
> > >
> > > > On Thu, 8 Oct 2015 10:21:05 +0800
> > > > Xishi Qiu <qiuxishi@xxxxxxxxxx> wrote:
> > > >
> > > > > If kernelcore was not specified, or the kernelcore size is zero
> > > > > (required_movablecore >= totalpages), or the kernelcore size is larger
> > > > Why does required_movablecore become larger than totalpages, when the
> > > > kernelcore size is zero? I read the code but I could not find that you
> > > > mention.
> > > If user only set boot option movablecore, and the value is larger than
> > > totalpages, the calculation of kernelcore is zero, but we can't fill
> > > the zone only with kernelcore, so skip it.
> > >
> > > I have send a patch before this patch.
> > > "fix overflow in find_zone_movable_pfns_for_nodes()"
> > >          ...
> > >            required_movablecore =
> > >                roundup(required_movablecore, MAX_ORDER_NR_PAGES);
> > > +        required_movablecore = min(totalpages, required_movablecore);
> > >            corepages = totalpages - required_movablecore;
> > >          ...
> >
> > So if required_movablecore >= totalpages, there won't be any ZONE_MOVABLE.
> > How about add a warning or debug info to tell the user he has specified a
> > too large movablecore, and it is ignored ?
> >
> > Thanks.
> Yes, but I don't think is is necessary, user should know the total memory
> before he set the boot option.

Well, I'm just thinking if I set a too large movablecore, but I didn't 
realize it.
And when the system boots up, there is no ZONE_MOVABLE. It may confuse me.

Thanks.

> Thanks,
> Xishi Qiu
>
> .

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/