From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: Re: [patch V2 01/29] tracing: Cleanup stack trace code Date: Thu, 18 Apr 2019 17:24:43 -0400 Message-ID: <20190418172443.30ec83e3@gandalf.local.home> References: <20190418084119.056416939@linutronix.de> <20190418084253.142712304@linutronix.de> <20190418135721.5vwd6ngxagrrrrtt@treble> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" To: Thomas Gleixner Cc: Mike Snitzer , David Airlie , Catalin Marinas , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, dm-devel@redhat.com, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , Marek Szyprowski , linux-arch@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, Johannes Thumshirn , Andrey Ryabinin , Alexey Dobriyan , intel-gfx@lists.freedesktop.org, David Rientjes , Akinobu Mita , Josef Bacik , Mike Rapoport , Andy Lutomirski , Josh Poimboeuf , David Sterba , Dmitry Vyukov List-Id: iommu@lists.linux-foundation.org T24gVGh1LCAxOCBBcHIgMjAxOSAyMzoxNDo0NSArMDIwMCAoQ0VTVCkKVGhvbWFzIEdsZWl4bmVy IDx0Z2x4QGxpbnV0cm9uaXguZGU+IHdyb3RlOgoKPiBPbiBUaHUsIDE4IEFwciAyMDE5LCBKb3No IFBvaW1ib2V1ZiB3cm90ZToKPiAKPiA+IE9uIFRodSwgQXByIDE4LCAyMDE5IGF0IDEwOjQxOjIw QU0gKzAyMDAsIFRob21hcyBHbGVpeG5lciB3cm90ZTogIAo+ID4gPiAtIFJlbW92ZSB0aGUgZXh0 cmEgYXJyYXkgbWVtYmVyIG9mIHN0YWNrX2R1bXBfdHJhY2VbXS4gSXQncyBub3QgcmVxdWlyZWQg YXMKPiA+ID4gICB0aGUgc3RhY2sgdHJhY2VyIHN0b3JlcyBhdCBtYXggYXJyYXkgc2l6ZSAtIDEg ZW50cmllcyBzbyB0aGVyZSBpcyBzdGlsbAo+ID4gPiAgIGFuIGVtcHR5IHNsb3QuICAKPiA+IAo+ ID4gV2hhdCBpcyB0aGUgZW1wdHkgc2xvdCB1c2VkIGZvcj8gIAo+IAo+IEkgd2FzIHRyeWluZyB0 byBmaW5kIGFuIGFuc3dlciBidXQgZmFpbGVkLiBNYXliZSBpdCdzIGp1c3QgaGlzdG9yaWNhbAo+ IGxlZnRvdmVycyBvciBTdGV2ZW4ga25vd3Mgd2hlcmUgdGhlIG1hZ2ljIGlzIGluIHRoaXMgbWF6 ZS4KPgoKSSBiZWxpZXZlIGl0IHdhcyBmb3IgaGlzdG9yaWNhbCBsZWZ0b3ZlcnMgKHRoZXJlIHdh cyBhIHRpbWUgaXQgd2FzCnJlcXVpcmVkKSwgYW5kIGxlZnQgdGhlcmUgZm9yICJwYXJhbm9pZCIg c2FrZS4gQnV0IGxldCBtZSBhcHBseSB0aGUKcGF0Y2ggYW5kIHNlZSBpZiBpdCBpcyByZWFsbHkg bmVlZGVkLgoKLS0gU3RldmUKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX18KSW50ZWwtZ2Z4IG1haWxpbmcgbGlzdApJbnRlbC1nZnhAbGlzdHMuZnJlZWRlc2t0 b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vaW50 ZWwtZ2Z4 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 557F5C10F0E for ; Thu, 18 Apr 2019 21:25:13 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 27B55205ED for ; Thu, 18 Apr 2019 21:25:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 27B55205ED Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 2E8241D0D; Thu, 18 Apr 2019 21:25:12 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 5638118AB for ; Thu, 18 Apr 2019 21:24:50 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 5B558823 for ; Thu, 18 Apr 2019 21:24:49 +0000 (UTC) Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DB27A205ED; Thu, 18 Apr 2019 21:24:45 +0000 (UTC) Date: Thu, 18 Apr 2019 17:24:43 -0400 From: Steven Rostedt To: Thomas Gleixner Subject: Re: [patch V2 01/29] tracing: Cleanup stack trace code Message-ID: <20190418172443.30ec83e3@gandalf.local.home> In-Reply-To: References: <20190418084119.056416939@linutronix.de> <20190418084253.142712304@linutronix.de> <20190418135721.5vwd6ngxagrrrrtt@treble> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Cc: Mike Snitzer , David Airlie , Catalin Marinas , Joonas Lahtinen , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, dm-devel@redhat.com, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , linux-arch@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, Johannes Thumshirn , Andrey Ryabinin , Alexey Dobriyan , intel-gfx@lists.freedesktop.org, David Rientjes , Maarten Lankhorst , Akinobu Mita , Jani Nikula , Josef Bacik , Rodrigo Vivi , Mike Rapoport , Andy Lutomirski , Josh Poimboeuf , David Sterba , Dmitry Vyukov , Chris Mason , LKML , Pekka Enberg , iommu@lists.linux-foundation.org, Daniel Vetter , Andrew Morton , Robin Murphy , linux-btrfs@vger.kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190418212443.tMmxTXagXCdpOUKb20vQwXb85X9tIDd7OZYuftCKXGs@z> On Thu, 18 Apr 2019 23:14:45 +0200 (CEST) Thomas Gleixner wrote: > On Thu, 18 Apr 2019, Josh Poimboeuf wrote: > > > On Thu, Apr 18, 2019 at 10:41:20AM +0200, Thomas Gleixner wrote: > > > - Remove the extra array member of stack_dump_trace[]. It's not required as > > > the stack tracer stores at max array size - 1 entries so there is still > > > an empty slot. > > > > What is the empty slot used for? > > I was trying to find an answer but failed. Maybe it's just historical > leftovers or Steven knows where the magic is in this maze. > I believe it was for historical leftovers (there was a time it was required), and left there for "paranoid" sake. But let me apply the patch and see if it is really needed. -- Steve _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu