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 D6B93C4320E for ; Fri, 30 Jul 2021 12:58:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF8BF60EBB for ; Fri, 30 Jul 2021 12:58:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238884AbhG3M66 (ORCPT ); Fri, 30 Jul 2021 08:58:58 -0400 Received: from foss.arm.com ([217.140.110.172]:41752 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230472AbhG3M64 (ORCPT ); Fri, 30 Jul 2021 08:58:56 -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 98C1F6D; Fri, 30 Jul 2021 05:58:51 -0700 (PDT) Received: from [10.57.86.111] (unknown [10.57.86.111]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0FD143F70D; Fri, 30 Jul 2021 05:58:49 -0700 (PDT) Subject: Re: [PATCH v2 05/10] coresight: trbe: Drop duplicate TRUNCATE flags To: Anshuman Khandual , 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> <0292cfc7-df67-aa45-4268-2ebc7f53420a@arm.com> From: Suzuki K Poulose Message-ID: <59ba694b-5bc3-1a51-38dc-7de90dff68ac@arm.com> Date: Fri, 30 Jul 2021 13:58:48 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: <0292cfc7-df67-aa45-4268-2ebc7f53420a@arm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 30/07/2021 05:47, Anshuman Khandual wrote: > > > 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); > Agreed, I will add this. Thanks Suzuki