From patchwork Fri Jul 23 12:46:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Suzuki K Poulose X-Patchwork-Id: 12396049 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=-18.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 F19F8C4338F for ; Fri, 23 Jul 2021 12:51:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 BFF2060E53 for ; Fri, 23 Jul 2021 12:51:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org BFF2060E53 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=mbHckjsAH9kn0HVmMAOEMFKzM4yPDHz/9NVs6hkES3I=; b=yxWUx5tzjfJAft AUTRXNEm2T2gvZby6rB9ejPHZj+VnBT8Xm5QNVRCnCaXdUEJFGkvBOaYwQbYOAXA71uAOjaTendF1 rcKCeyrkb9CDitexyP2He+Sijfagwil9hEX9oXnqaeRMOUJLDJ/z+qqLPKqwGrwJbjC1OTKHrnEcC 4nAGEPHunvFey/I3M7MfC6Gqx4H+J52c9geexTYGpSqVrSM2cNprRUaFu8ug+xmdQF6IzCw4IQ1Yc 4VMR+JNwTwHl4lGlzt2jG06hDYPFzv4w6xVyDIjk5y7zPvvt3r60Ckkk1zsMHrPeAchQszIo2IztH xovMtm14CwK0328s6fNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6ucV-004gZq-JQ; Fri, 23 Jul 2021 12:49:39 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m6uZX-004fB2-Te for linux-arm-kernel@lists.infradead.org; Fri, 23 Jul 2021 12:46:37 +0000 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 8CB051063; Fri, 23 Jul 2021 05:46:35 -0700 (PDT) Received: from ewhatever.cambridge.arm.com (ewhatever.cambridge.arm.com [10.1.197.1]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DFF213F694; Fri, 23 Jul 2021 05:46:33 -0700 (PDT) From: Suzuki K Poulose To: 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, suzuki.poulose@arm.com, anshuman.khandual@arm.com, jinlmao@qti.qualcomm.com, Peter Zijlstra , Will Deacon Subject: [PATCH v2 09/10] coresight: trbe: End the AUX handle on truncation Date: Fri, 23 Jul 2021 13:46:10 +0100 Message-Id: <20210723124611.3828908-10-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210723124611.3828908-1-suzuki.poulose@arm.com> References: <20210723124611.3828908-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210723_054636_133702_4AC5CBC2 X-CRM114-Status: GOOD ( 15.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org When we detect that there isn't enough space left to start a meaningful session, we disable the TRBE, marking the buffer as TRUNCATED. But we delay the notification to the perf layer by perf_aux_output_end() until the event is scheduled out. This will cause significant black outs in the trace. Now that the CoreSight PMU layer can handle a closed "AUX" handle properly, we can close the handle as soon as we detect the case, allowing the userspace to collect and re-enable the event. Also, while in the IRQ handler, move the irq_work_run() after we have updated the handle, to make sure the "TRUNCATED" flag causes the event to be disabled as soon as possible. Cc: Anshuman Khandual Cc: Mathieu Poirier Cc: Mike Leach Cc: Leo Yan Cc: Peter Zijlstra (Intel) Cc: Will Deacon Signed-off-by: Suzuki K Poulose Reviewed-by: Anshuman Khandual --- drivers/hwtracing/coresight/coresight-trbe.c | 25 ++++++++++++-------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 6d6aad171c72..e7567727e8fc 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -134,6 +134,7 @@ static void trbe_stop_and_truncate_event(struct perf_output_handle *handle) trbe_drain_and_disable_local(); perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED | PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW); + perf_aux_output_end(handle, 0); *this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL; } @@ -699,7 +700,7 @@ static void trbe_handle_spurious(struct perf_output_handle *handle) isb(); } -static void trbe_handle_overflow(struct perf_output_handle *handle) +static int trbe_handle_overflow(struct perf_output_handle *handle) { struct perf_event *event = handle->event; struct trbe_buf *buf = etm_perf_sink_config(handle); @@ -728,10 +729,10 @@ static void trbe_handle_overflow(struct perf_output_handle *handle) */ trbe_drain_and_disable_local(); *this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL; - return; + return -EINVAL; } - __arm_trbe_enable(buf, handle); + return __arm_trbe_enable(buf, handle); } static bool is_perf_trbe(struct perf_output_handle *handle) @@ -762,6 +763,7 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev) struct perf_output_handle *handle = *handle_ptr; enum trbe_fault_action act; u64 status; + bool truncated = false; /* Reads to TRBSR_EL1 is fine when TRBE is active */ status = read_sysreg_s(SYS_TRBSR_EL1); @@ -786,24 +788,27 @@ static irqreturn_t arm_trbe_irq_handler(int irq, void *dev) if (!is_perf_trbe(handle)) return IRQ_NONE; - /* - * Ensure perf callbacks have completed, which may disable - * the trace buffer in response to a TRUNCATION flag. - */ - irq_work_run(); - act = trbe_get_fault_act(status); switch (act) { case TRBE_FAULT_ACT_WRAP: - trbe_handle_overflow(handle); + truncated = !!trbe_handle_overflow(handle); break; case TRBE_FAULT_ACT_SPURIOUS: trbe_handle_spurious(handle); break; case TRBE_FAULT_ACT_FATAL: trbe_stop_and_truncate_event(handle); + truncated = true; break; } + + /* + * If the buffer was truncated, ensure perf callbacks + * have completed, which will disable the event. + */ + if (truncated) + irq_work_run(); + return IRQ_HANDLED; }