linux-kernel - Re: [PATCH 0/6] PM / Hibernate: Memory bitmap scalability improvements

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Sat, 19 Jul 2014 12:26:23 +0200
From:	Pavel Machek <pavel@....cz>
To:	Joerg Roedel <joro@...tes.org>
Cc:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	Len Brown <len.brown@...el.com>, linux-pm@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/6] PM / Hibernate: Memory bitmap scalability
 improvements

Hi!

> here is a patch set to improve the scalability of the memory
> bitmap implementation used for hibernation. The current
> implementation does not scale well to machines with several
> TB of memory. A resume on those machines may cause soft
> lockups to be reported.
> 
> These patches improve the data structure by adding a radix
> tree to the linked list structure to improve random access
> performance from O(n) to O(log_b(n)), where b depends on the
> architecture (b=512 on amd64, 1024 in i386).
> 
> A test on a 12TB machine showed an improvement in resume
> time from 76s with the old implementation to 2.4s with the
> radix tree and the improved swsusp_free function. See below
> for details of this test.

Ok, nice.

How did space requirements change?

In particular, do we need to reserve a bit more pages for hibernation
now?

Thanks,
									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/