From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753707AbaEWRPI (ORCPT ); Fri, 23 May 2014 13:15:08 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3941 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753683AbaEWRPG (ORCPT ); Fri, 23 May 2014 13:15:06 -0400 Date: Fri, 23 May 2014 19:14:26 +0200 From: Jiri Olsa To: Don Zickus Cc: acme@ghostprotocols.net, peterz@infradead.org, LKML , namhyung@gmail.com, eranian@google.com, Andi Kleen Subject: Re: [PATCH 7/7] perf: Add dcacheline sort Message-ID: <20140523171426.GG1074@krava> References: <1400526833-141779-1-git-send-email-dzickus@redhat.com> <1400526833-141779-8-git-send-email-dzickus@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1400526833-141779-8-git-send-email-dzickus@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 19, 2014 at 03:13:53PM -0400, Don Zickus wrote: > In perf's 'mem-mode', one can get access to a whole bunch of details specific to a > particular sample instruction. A bunch of those details relate to the data > address. > > One interesting thing you can do with data addresses is to convert them into a unique > cacheline they belong too. Organizing these data cachelines into similar groups and sorting > them can reveal cache contention. > > This patch creates an alogorithm based on various sample details that can help group > entries together into data cachelines and allows 'perf report' to sort on it. > > The algorithm relies on having proper mmap2 support in the kernel to help determine > if the memory map the data address belongs to is private to a pid or globally shared. > > The alogortithm is as follows: > > o group cpumodes together > o group entries with discovered maps together > o sort on major, minor, inode and inode generation numbers > o if userspace anon, then sort on pid > o sort on cachelines based on data addresses > > The 'dcacheline' sort option in 'perf report' only works in 'mem-mode'. > > Sample output: > > # > # Samples: 206 of event 'cpu/mem-loads/pp' > # Total weight : 2534 > # Sort order : dcacheline,pid > # > # Overhead Samples Data Cacheline Command: Pid > # ........ ............ ...................................................................... .................. > # > 13.22% 1 [k] 0xffff88042f08ebc0 swapper: 0 > 9.27% 1 [k] 0xffff88082e8cea80 swapper: 0 > 3.59% 2 [k] 0xffffffff819ba180 swapper: 0 > 0.32% 1 [k] arch_trigger_all_cpu_backtrace_handler_na.23901+0xffffffffffffffe0 swapper: 0 > 0.32% 1 [k] timekeeper_seq+0xfffffffffffffff8 swapper: 0 > > Note: Added a '+1' to symlen size in hists__calc_col_len to prevent the next column > from prematurely tabbing over and mis-aligning. Not sure what the problem is. I think thats the extra '+' sign ;-) so +1 seems ok jirka