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 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 7F64AC04AB1 for ; Mon, 13 May 2019 11:12:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 506BB2146F for ; Mon, 13 May 2019 11:12:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729265AbfEMLMI (ORCPT ); Mon, 13 May 2019 07:12:08 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:55678 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728713AbfEMLMH (ORCPT ); Mon, 13 May 2019 07:12:07 -0400 Received: from DGGEMS412-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id 2AE843B18879504E3740; Mon, 13 May 2019 19:12:06 +0800 (CST) Received: from [127.0.0.1] (10.177.223.23) by DGGEMS412-HUB.china.huawei.com (10.3.19.212) with Microsoft SMTP Server id 14.3.439.0; Mon, 13 May 2019 19:11:57 +0800 Subject: Re: [PATCH v3 0/5] arm64: SPE ACPI enablement To: Sudeep Holla , Will Deacon CC: Jeremy Linton , , , , , , , , , , Hongbo Yao , "Alexander Shishkin" References: <20190503232407.37195-1-jeremy.linton@arm.com> <5eaa1607-4bf0-a320-e9cf-2d51eca912c6@huawei.com> <82032e5b-0cb5-e48f-ab51-ba5d5f9dceec@arm.com> <819de863-92ff-51c5-9c35-880db4f6a922@huawei.com> <20190508165149.GB21553@e107155-lin> <20190509092810.GC2667@brain-police> <20190509103559.GB8239@e107155-lin> From: Hanjun Guo Message-ID: Date: Mon, 13 May 2019 19:10:56 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20190509103559.GB8239@e107155-lin> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.223.23] X-CFilter-Loop: Reflected Sender: linux-acpi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org On 2019/5/9 18:35, Sudeep Holla wrote: > On Thu, May 09, 2019 at 10:28:11AM +0100, Will Deacon wrote: >> On Wed, May 08, 2019 at 05:51:49PM +0100, Sudeep Holla wrote: >>> On Wed, May 08, 2019 at 05:35:51PM +0800, Hanjun Guo wrote: [...] >>>>>> >>>>>> Adding this patch set on top of latest mainline kernel, >>>>>> and tested on D06 which has the SPE feature, in boot message >>>>>> shows it was probed successfully: >>>>>> >>>>>> arm_spe_pmu arm,spe-v1: probed for CPUs 0-95 [max_record_sz 128, align 4, features 0x7] >>>>>> >>>>>> but when I test it with spe events such as >>>>>> >>>>>> perf record -c 1024 -e arm_spe_0/branch_filter=0/ -o spe ls >>>>>> >>>>>> it fails with: >>>>>> failed to mmap with 12 (Cannot allocate memory), >>>>>> >>>>>> Confirmed that patch [0] is merged and other perf events are working >>>>>> fine. >>>>> >>>>> Its pretty easy to get into the weeds with this driver, does it work with examples like: >>>>> >>>>> https://lkml.org/lkml/2018/1/14/122 >>>> >>>> No, not work at all. >>>> >>>> SPE works on 5.0, but not work after 5.1-rc1, bisected to this commit: >>>> >>>> 5768402fd9c6 perf/ring_buffer: Use high order allocations for AUX buffers optimistically >>>> >>> >>> Indeed this patch breaks SPE. As mentioned in the patch, it uses high >>> order allocations for AUX buffers and SPE PMU setup_aux explicitly >>> fails with the warning "unexpected high-order page for auxbuf!" if >>> it encounters one. >>> >>> I don't know the intention of that check in SPE. Will ? >> >> Since SPE uses virtual addressing, we don't really care about the underlying >> page layout so there's no need to use higher-order allocations. I suppose we >> could theoretically map them at the pmd level in some cases, but ignoring >> them should also be harmless and I suspect you can delete the check. >> > > Yes, I did a quick look to see if we can do that, but couldn't find a clue. > Not sure if that's any optimisation, we can use order from page_private > and set the values accordingly ? > >> Does the patch below fix the problem? >> > > Yes it should help, I tried exactly the same thing yesterday and it does > fix the issue. Works for me too, thank you Sudeep and Will for looking into this issue. Best Regards Hanjun