Re: [PATCH 0/6 v2] PM / Hibernate: Memory bitmap scalability improvements

From: Pavel Machek
Date: Tue Jul 22 2014 - 06:58:29 EST


On Tue 2014-07-22 12:34:44, Joerg Roedel wrote:
> On Tue, Jul 22, 2014 at 02:41:29AM +0200, Rafael J. Wysocki wrote:
> > It looks like some specific need motivated the Joerg's work, however,
> > so let's just not dismiss the use case lightly without knowing it.
>
> The motivation was to optimize the data structures for machines with
> large amounts of RAM without penalizing average machines. On a 12TB
> machine you are close to 100000 pages just for one bitmap. Scanning
> through that linearly to find a given bit just doesnt scale anymore in
> this case.

Can you produce backtrace where 12TB machine spends time during boot
with resume= parameter but no suspend image?

AFAICT swsusp_check() does not play with bitmaps.
Pavel
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