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=-15.4 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 31AA6C4338F for ; Fri, 30 Jul 2021 04:46:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 04BD460F01 for ; Fri, 30 Jul 2021 04:46:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231138AbhG3Eqp (ORCPT ); Fri, 30 Jul 2021 00:46:45 -0400 Received: from foss.arm.com ([217.140.110.172]:36388 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229609AbhG3Eqn (ORCPT ); Fri, 30 Jul 2021 00:46:43 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1440331B; Thu, 29 Jul 2021 21:46:39 -0700 (PDT) Received: from [10.163.66.9] (unknown [10.163.66.9]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5AFB73F73D; Thu, 29 Jul 2021 21:46:36 -0700 (PDT) Subject: Re: [PATCH v2 05/10] coresight: trbe: Drop duplicate TRUNCATE flags To: Suzuki K Poulose , coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, tamas.zsoldos@arm.com, al.grant@arm.com, leo.yan@linaro.org, mike.leach@linaro.org, mathieu.poirier@linaro.org, jinlmao@qti.qualcomm.com References: <20210723124611.3828908-1-suzuki.poulose@arm.com> <20210723124611.3828908-6-suzuki.poulose@arm.com> From: Anshuman Khandual Message-ID: <0292cfc7-df67-aa45-4268-2ebc7f53420a@arm.com> Date: Fri, 30 Jul 2021 10:17:25 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210723124611.3828908-6-suzuki.poulose@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/23/21 6:16 PM, Suzuki K Poulose wrote: > We mark the buffer as TRUNCATED when there is no space left > in the buffer. But we do it at different points. > __trbe_normal_offset() > and also, at all the callers of the above function via > compute_trbe_buffer_limit(), when the limit == base (i.e > offset = 0 as returned by the __trbe_normal_offset()). > > So, given that the callers already mark the buffer as TRUNCATED > drop the caller inside the __trbe_normal_offset(). > > This is in preparation to moving the handling of TRUNCATED > into a central place. > > Cc: Anshuman Khandual > Cc: Mathieu Poirier > Cc: Mike Leach > Cc: Leo Yan > Signed-off-by: Suzuki K Poulose > --- > drivers/hwtracing/coresight/coresight-trbe.c | 7 +------ > 1 file changed, 1 insertion(+), 6 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c > index 446f080f8320..62e1a08f73ff 100644 > --- a/drivers/hwtracing/coresight/coresight-trbe.c > +++ b/drivers/hwtracing/coresight/coresight-trbe.c > @@ -253,13 +253,9 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle) > * trbe_base trbe_base + nr_pages > * > * Perf aux buffer does not have any space for the driver to write into. > - * Just communicate trace truncation event to the user space by marking > - * it with PERF_AUX_FLAG_TRUNCATED. > */ > - if (!handle->size) { > - perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); > + if (!handle->size) > return 0; > - } > > /* Compute the tail and wakeup indices now that we've aligned head */ > tail = PERF_IDX2OFF(handle->head + handle->size, buf); > @@ -361,7 +357,6 @@ static unsigned long __trbe_normal_offset(struct perf_output_handle *handle) > return limit; > > trbe_pad_buf(handle, handle->size); > - perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); > return 0; > } What about in trbe_handle_spurious() path which used to set the flag via compute_trbe_buffer_limit(), but would not any more after this change. I guess following additional change would be required to preserve the past behaviour. --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -685,6 +685,7 @@ static void trbe_handle_spurious(struct perf_output_handle *handle) buf->trbe_write = buf->trbe_base + PERF_IDX2OFF(handle->head, buf); if (buf->trbe_limit == buf->trbe_base) { trbe_drain_and_disable_local(); + perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED); return; } trbe_enable_hw(buf);