linux-kernel - Re: [regression v4.0-rc1] mm: IPIs from TLB flushes causing significant performance degradation.

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-ID: <20150304235126.GB18360@dastard>
Date:	Thu, 5 Mar 2015 10:51:26 +1100
From:	Dave Chinner <david@...morbit.com>
To:	Ingo Molnar <mingo@...nel.org>
Cc:	Mel Gorman <mgorman@...e.de>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Matt B <jackdachef@...il.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	linux-mm <linux-mm@...ck.org>, xfs@....sgi.com
Subject: Re: [regression v4.0-rc1] mm: IPIs from TLB flushes causing
 significant performance degradation.

On Thu, Mar 05, 2015 at 12:35:45AM +0100, Ingo Molnar wrote:
> 
> * Dave Chinner <david@...morbit.com> wrote:
> 
> > > After going through the series again, I did not spot why there is 
> > > a difference. It's functionally similar and I would hate the 
> > > theory that this is somehow hardware related due to the use of 
> > > bits it takes action on.
> > 
> > I doubt it's hardware related - I'm testing inside a VM, [...]
> 
> That might be significant, I doubt Mel considered KVM's interpretation 
> of pte details?

I did actaully mention that before:

| I am running a fake-numa=4 config on this test VM so it's got 4
| nodes of 4p/4GB RAM each.

but I think it got snipped before Mel was cc'd.

Perhaps size of the nodes is relevant, too, because the steady state
phase 3 memory usage is 5-6GB when this problem first shows up, and
then continues into phase 4 where memory usage grows again and peaks
at ~10GB....

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com
--
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/