linux-kernel - Re: [PATCH] mm: clear 1G pages with streaming stores on x86

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 linux-cve-announce 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]

Message-ID: <20200309153325.GJ1454533@tassilo.jf.intel.com>
Date:   Mon, 9 Mar 2020 08:33:25 -0700
From:   Andi Kleen <ak@...ux.intel.com>
To:     "Kirill A. Shutemov" <kirill@...temov.name>
Cc:     Cannon Matthews <cannonmatthews@...gle.com>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Matthew Wilcox <willy@...radead.org>,
        Michal Hocko <mhocko@...nel.org>,
        David Rientjes <rientjes@...gle.com>,
        Greg Thelen <gthelen@...gle.com>,
        Salman Qazi <sqazi@...gle.com>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [PATCH] mm: clear 1G pages with streaming stores on x86

> > Tested:
> > 	Time to `mlock()` a 512GiB region on broadwell CPU
> > 				AVG time (s)	% imp.	ms/page
> > 	clear_page_erms		133.584		-	261
> > 	clear_page_nt		34.154		74.43%	67
> 
> Some macrobenchmark would be great too.

Yes especially something that actually uses the memory. I suspect you'll need
something like the below

> That patchset is somewhat more complex trying to keep the memory around
> the fault address hot in cache. In theory it should help to reduce latency
> on the first access to the memory.

-Andi