linux-kernel - Re: [PATCH 09/11] perf/x86/intel: Implement LRU monitoring ID allocation for CQM

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

Date:	Wed, 8 Oct 2014 11:51:09 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Matt Fleming <matt@...sole-pimps.org>
Cc:	Ingo Molnar <mingo@...nel.org>, Jiri Olsa <jolsa@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
	Matt Fleming <matt.fleming@...el.com>,
	Arnaldo Carvalho de Melo <acme@...hat.com>
Subject: Re: [PATCH 09/11] perf/x86/intel: Implement LRU monitoring ID
 allocation for CQM

On Wed, Sep 24, 2014 at 03:04:13PM +0100, Matt Fleming wrote:
> From: Matt Fleming <matt.fleming@...el.com>
> 
> It's possible to run into issues with re-using unused monitoring IDs
> because there may be stale cachelines associated with that ID from a
> previous allocation. This can cause the LLC occupancy values to be
> inaccurate.
> 
> To attempt to mitigate this problem we place the IDs on a least recently
> used list, essentially a FIFO. The basic idea is that the longer the
> time period between ID re-use the lower the probability that stale
> cachelines exist in the cache.

Do we want to provide a user configurable minumum guaranteed queue time?
--
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/