Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757110Ab2EXBrU (ORCPT ); Wed, 23 May 2012 21:47:20 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:46378 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755052Ab2EXBrT (ORCPT ); Wed, 23 May 2012 21:47:19 -0400 MIME-Version: 1.0 In-Reply-To: <1337793338.9783.38.camel@laptop> References: <1337782555-8088-1-git-send-email-alex.shi@intel.com> <1337782555-8088-9-git-send-email-alex.shi@intel.com> <4FBD18D20200007800085951@nat28.tlf.novell.com> <1337792984.9783.37.camel@laptop> <1337793338.9783.38.camel@laptop> From: Andrew Lutomirski Date: Wed, 23 May 2012 18:46:58 -0700 X-Google-Sender-Auth: eS4jcqCsUOoauEdFeC5_tBfYltQ Message-ID: Subject: Re: [PATCH v7 8/8] x86/tlb: just do tlb flush on one of siblings of SMT To: Peter Zijlstra Cc: Jan Beulich , Alex Shi , borislav.petkov@amd.com, arnd@arndb.de, akinobu.mita@gmail.com, eric.dumazet@gmail.com, fweisbec@gmail.com, rostedt@goodmis.org, hughd@google.com, jeremy@goop.org, len.brown@intel.com, tony.luck@intel.com, yongjie.ren@intel.com, kamezawa.hiroyu@jp.fujitsu.com, seto.hidetoshi@jp.fujitsu.com, penberg@kernel.org, yinghai@kernel.org, tglx@linutronix.de, akpm@linux-foundation.org, ak@linux.intel.com, avi@redhat.com, dhowells@redhat.com, mingo@redhat.com, riel@redhat.com, cpw@sgi.com, steiner@sgi.com, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk, hpa@zytor.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 980 Lines: 23 On Wed, May 23, 2012 at 10:15 AM, Peter Zijlstra wrote: > On Wed, 2012-05-23 at 19:09 +0200, Peter Zijlstra wrote: >> > There is no comment or anything else indicating that this is >> > suitable for dual-thread CPUs only - when there are more than >> > 2 threads per core, the intended effect won't be achieved. >> >> Why would that be? Won't higher thread count still share the same >> resources just more so? > > Ah, I see, you're saying his code is buggy for >2 threads. Agreed. > An evil knob to statically choose which SMT sibling gets the interrupt would be nice. Then my compute-intensive thread could be (mostly) unaffected by the other thread on a different core that calls munmap frequently. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/