From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753245AbaE1Rtg (ORCPT ); Wed, 28 May 2014 13:49:36 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:49351 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751413AbaE1Rtf (ORCPT ); Wed, 28 May 2014 13:49:35 -0400 Date: Wed, 28 May 2014 19:49:27 +0200 From: Peter Zijlstra To: Andi Kleen Cc: Stephane Eranian , "Yan, Zheng" , LKML , "mingo@elte.hu" Subject: Re: [RFC PATCH 6/7] perf, x86: large PEBS interrupt threshold Message-ID: <20140528174927.GY30445@twins.programming.kicks-ass.net> References: <1401257890-30535-1-git-send-email-zheng.z.yan@intel.com> <1401257890-30535-7-git-send-email-zheng.z.yan@intel.com> <20140528081053.GP11096@twins.programming.kicks-ass.net> <20140528145831.GH29957@tassilo.jf.intel.com> <20140528165144.GK29957@tassilo.jf.intel.com> <20140528171243.GL29957@tassilo.jf.intel.com> <20140528171957.GW30445@twins.programming.kicks-ass.net> <20140528174545.GN29957@tassilo.jf.intel.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="PlWN2or5MzbGPm4Y" Content-Disposition: inline In-Reply-To: <20140528174545.GN29957@tassilo.jf.intel.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --PlWN2or5MzbGPm4Y Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, May 28, 2014 at 10:45:45AM -0700, Andi Kleen wrote: > > So the window is fairly large for another to slip in, esp if you have a > > fast (say inst-ret) and a slow (say br-misp) event. >=20 > yes, but unless you have really small periods it's still very unlikely > that they synchronize, so it will only happen very rarely. And the > rare cases won't affect the statistics very much. Sure, but it might be an information leak... Not sure how severe these are, but again.. it blows to have to worry about this when it would've been 'trivial' to actually fix. --PlWN2or5MzbGPm4Y Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJThiGnAAoJEHZH4aRLwOS6MZIP/08dAfAbfRAas5XC15Tkn4M3 hRJFnMwZYZNAuNWy7CXKtRrSWNmt7xdy0tUtQeQNFKTKZfY5FE0ET8Mg37Vqw74N ovlPY/o+bCXoFD1JKBA/w0ScBmI1mNma5Egs5WW60ZWz0GuU9b4OBjT1+Lyqat1L ty/9nFQH/1MooYVudZkXhg6TpptkIOMI4oDyNwuVcwyez48/FaQ+dETCyM6S/aCV nsvM7LZvXcRu5xAwx3GQQVt8ms7vETHmYvWw0D1sSI/w/QQp13QBZMIfRB8pp3GD cVPuWiG4qTi2OPgu8CABHGZuWrJtMdcOtheVm/8YVwDvvHBU4btDbxEhnPLljAtw xqvG3Q60n32j9vwKjuXacSvyj6jJuF4wj8uchhy7Yviu4Zee9zC7D+7LwgEuUXqZ septmtV6MqyTY9NgrpDvCyTZemWtbVcpavnv6gmzEsAlUaZcby/k6ELUvoh55BOF P78YxqX9/tNTbiZWU/mitp3s/k4JIiH+loINIOPgMOEu/prA2nGFfQF+HS8xdwAQ Vm3esLVEmzgZ62QQ0NL6ZOE9sRllwRSx0XYnWJo6Md/r8Cqav88SxzRuWkk3dzoT h6+bE8/BPULEoQD+YScir0qLzSLIWDaxBkuoO15leKFrhBK8YKPoTVSDLGxJjplW rpllDss3o6nxK3h0bhbn =hAM2 -----END PGP SIGNATURE----- --PlWN2or5MzbGPm4Y--