Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754751AbbLJIBf (ORCPT ); Thu, 10 Dec 2015 03:01:35 -0500 Received: from mail-wm0-f46.google.com ([74.125.82.46]:38649 "EHLO mail-wm0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754133AbbLJIBX (ORCPT ); Thu, 10 Dec 2015 03:01:23 -0500 Date: Thu, 10 Dec 2015 09:01:18 +0100 From: Ingo Molnar To: Namhyung Kim Cc: Arnaldo Carvalho de Melo , Peter Zijlstra , Jiri Olsa , LKML , David Ahern , Frederic Weisbecker , Andi Kleen , Stephane Eranian , Adrian Hunter Subject: Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Message-ID: <20151210080118.GA8664@gmail.com> References: <1449734015-9148-1-git-send-email-namhyung@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1449734015-9148-1-git-send-email-namhyung@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1179 Lines: 31 * Namhyung Kim wrote: > Hello, > > This patchset if an attempt to support multi-threading in perf top. > In fact, perf top already run on two threads - a worker thread and a > display thread. However processing all samples with a single thread > in a large machine can have scalability problems. > > This patchset extends it to have multiple worker threads to process > samples concurrently. Users can control the number of threads using > --num-thread option. And there's a collector thread for passing hist > entries from worker threads to the display thread. Could you please make the number of threads default to the number of CPUs? Since perf top is doing one perf event per CPU anyway, that's a pretty natural model. ( I think 'perf record' should use per CPU threads as well to receive events, to address the 'IO overload' problems with -g recording on larger CPU counts. ) Thanks, Ingo -- 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/