From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754592AbdBVKwO (ORCPT ); Wed, 22 Feb 2017 05:52:14 -0500 Received: from mx2.suse.de ([195.135.220.15]:50774 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753338AbdBVKwH (ORCPT ); Wed, 22 Feb 2017 05:52:07 -0500 Date: Wed, 22 Feb 2017 11:51:56 +0100 From: Jan Kara To: Ross Zwisler Cc: Andrew Morton , linux-kernel@vger.kernel.org, Jan Kara , Alexander Viro , Dan Williams , Ingo Molnar , Matthew Wilcox , Steven Rostedt , linux-fsdevel@vger.kernel.org, linux-nvdimm@ml01.01.org Subject: Re: [PATCH 0/6] second round of tracepoints for DAX Message-ID: <20170222105156.GC23312@quack2.suse.cz> References: <20170221195116.13278-1-ross.zwisler@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170221195116.13278-1-ross.zwisler@linux.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 21-02-17 12:51:10, Ross Zwisler wrote: > This second round of DAX tracepoint patches adds tracing to the PTE fault > path (dax_iomap_pte_fault(), dax_pfn_mkwrite(), dax_load_hole(), > dax_insert_mapping()) and to the writeback path > (dax_writeback_mapping_range(), dax_writeback_one()). > > The purpose of this tracing is to give us a high level view of what DAX is > doing, whether faults are being serviced by PMDs or PTEs, and by real > storage or by zero pages covering holes. > > I do have some patches nearly ready which also add tracing to > grab_mapping_entry() and dax_insert_mapping_entry(). These are more > targeted at logging how we are interacting with the radix tree, how we use > empty entries for locking, whether we "downgrade" huge zero pages to > 4k PTE sized allocations, etc. In the end it seemed to me that this might > be too detailed to have as constantly present tracepoints, but if anyone > sees value in having tracepoints like this in the DAX code permanently > (Jan?), please let me know and I'll add those last two patches. Yeah, for now I think it is too detailed and high-level logging is good enough. As we will debug problems, we may find places that are useful for more detailed tracepoints but for now what you added looks fine. > All these tracepoints were done to be consistent with the style of the XFS > tracepoints and with the existing DAX PMD tracepoints. > > This series applies cleanly to the current mmots/master: > > commit 35aa45ffe8d9 ("pci: test for unexpectedly disabled bridges") > > and I'm hoping that it'll end up going to Linus through akpm's -mm tree. I like the patches and they look fine to me. Feel free to add: Reviewed-by: Jan Kara Honza -- Jan Kara SUSE Labs, CR