From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758657AbaDVVUG (ORCPT ); Tue, 22 Apr 2014 17:20:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54449 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757662AbaDVVT7 (ORCPT ); Tue, 22 Apr 2014 17:19:59 -0400 Message-ID: <5356DCEF.3050506@redhat.com> Date: Tue, 22 Apr 2014 17:19:43 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.3.0 MIME-Version: 1.0 To: Dave Hansen , x86@kernel.org CC: linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, mgorman@suse.de, ak@linux.intel.com, alex.shi@linaro.org, dave.hansen@linux.intel.com Subject: Re: [PATCH 4/6] x86: mm: trace tlb flushes References: <20140421182418.81CF7519@viggo.jf.intel.com> <20140421182425.93E696A3@viggo.jf.intel.com> In-Reply-To: <20140421182425.93E696A3@viggo.jf.intel.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/21/2014 02:24 PM, Dave Hansen wrote: > From: Dave Hansen > > We don't have any good way to figure out what kinds of flushes > are being attempted. Right now, we can try to use the vm > counters, but those only tell us what we actually did with the > hardware (one-by-one vs full) and don't tell us what was actually > _requested_. > > This allows us to select out "interesting" TLB flushes that we > might want to optimize (like the ranged ones) and ignore the ones > that we have very little control over (the ones at context > switch). > > Also, since we have a pair of tracepoint calls in > flush_tlb_mm_range(), we can time the deltas between them to make > sure that we got the "invlpg vs. global flush" balance correct in > practice. > > Signed-off-by: Dave Hansen Acked-by: Rik van Riel -- All rights reversed