From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752376AbdLFPUr (ORCPT ); Wed, 6 Dec 2017 10:20:47 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:2261 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751904AbdLFPUn (ORCPT ); Wed, 6 Dec 2017 10:20:43 -0500 Subject: Re: [RFC PATCH 2/5] perf jevents: add support for arch recommended events To: Jiri Olsa References: <1512490399-94107-1-git-send-email-john.garry@huawei.com> <1512490399-94107-3-git-send-email-john.garry@huawei.com> <20171206133607.GA12508@krava> CC: , , , , , , , , , , , , , , , From: John Garry Message-ID: Date: Wed, 6 Dec 2017 15:20:14 +0000 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <20171206133607.GA12508@krava> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12/2017 13:36, Jiri Olsa wrote: > On Wed, Dec 06, 2017 at 12:13:16AM +0800, John Garry wrote: >> For some architectures (like arm64), there are architecture- >> defined recommended events. Vendors may not be obliged to >> follow the recommendation and may implement their own pmu >> event for a specific event code. >> >> This patch adds support for parsing events from arch-defined >> recommended JSONs, and then fixing up vendor events when >> they have implemented these events as recommended. > > in the previous patch you added the vendor support, so > you have arch|vendor|platform key for the event list > and perf have the most current/local event list > > why would you need to fix it? if there's new event list, > the table gets updated, perf is rebuilt.. I'm clearly > missing something ;-) The 2 patches are quite separate. In the first patch, I just added support for the vendor subdirectory. So this patch is not related to rebuilding when adding a new event list or dependency checking. Here we are trying to allow the vendor to just specify that an event is supported as standard in their platform, without duplicating all the standard event fields in their JSON. When processing the vendor JSONs, the jevents tool can figure which events are standard and create the proper event entries in the pmu events table, referencing the architecture JSON. > >> In the vendor JSON, to specify that the event is supported >> according to the recommendation, only the event code is >> added to the JSON entry - no other event elements need be >> added, like below: >> [ >> { >> "EventCode": "0x40", >> }, >> >> ] >> >> The pmu event parsing will check for "BriefDescription" >> field presence only for this. >> >> If "BriefDescription" is present, then it is implied >> that the vendor has implemented their own custom event, >> and there is no fixup. Other fields are ignored. > > if we are going this way, please use some new token, > this list is supposed to be human readable A new token could work also, but it would be just a flag to mark the event "standard". Ideally we could reference another entry in another JSON, like a pointer, but I don't think that this is possible with JSONs; not unless we introduce some elaborate custom scheme to allow JSONs to be cross-referenced. Cheers, John > > thanks, > jirka > > . > From mboxrd@z Thu Jan 1 00:00:00 1970 From: john.garry@huawei.com (John Garry) Date: Wed, 6 Dec 2017 15:20:14 +0000 Subject: [RFC PATCH 2/5] perf jevents: add support for arch recommended events In-Reply-To: <20171206133607.GA12508@krava> References: <1512490399-94107-1-git-send-email-john.garry@huawei.com> <1512490399-94107-3-git-send-email-john.garry@huawei.com> <20171206133607.GA12508@krava> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/12/2017 13:36, Jiri Olsa wrote: > On Wed, Dec 06, 2017 at 12:13:16AM +0800, John Garry wrote: >> For some architectures (like arm64), there are architecture- >> defined recommended events. Vendors may not be obliged to >> follow the recommendation and may implement their own pmu >> event for a specific event code. >> >> This patch adds support for parsing events from arch-defined >> recommended JSONs, and then fixing up vendor events when >> they have implemented these events as recommended. > > in the previous patch you added the vendor support, so > you have arch|vendor|platform key for the event list > and perf have the most current/local event list > > why would you need to fix it? if there's new event list, > the table gets updated, perf is rebuilt.. I'm clearly > missing something ;-) The 2 patches are quite separate. In the first patch, I just added support for the vendor subdirectory. So this patch is not related to rebuilding when adding a new event list or dependency checking. Here we are trying to allow the vendor to just specify that an event is supported as standard in their platform, without duplicating all the standard event fields in their JSON. When processing the vendor JSONs, the jevents tool can figure which events are standard and create the proper event entries in the pmu events table, referencing the architecture JSON. > >> In the vendor JSON, to specify that the event is supported >> according to the recommendation, only the event code is >> added to the JSON entry - no other event elements need be >> added, like below: >> [ >> { >> "EventCode": "0x40", >> }, >> >> ] >> >> The pmu event parsing will check for "BriefDescription" >> field presence only for this. >> >> If "BriefDescription" is present, then it is implied >> that the vendor has implemented their own custom event, >> and there is no fixup. Other fields are ignored. > > if we are going this way, please use some new token, > this list is supposed to be human readable A new token could work also, but it would be just a flag to mark the event "standard". Ideally we could reference another entry in another JSON, like a pointer, but I don't think that this is possible with JSONs; not unless we introduce some elaborate custom scheme to allow JSONs to be cross-referenced. Cheers, John > > thanks, > jirka > > . >