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=-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 400BAC433F5 for ; Thu, 23 Sep 2021 14:41:51 +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 0170F603E5 for ; Thu, 23 Sep 2021 14:41:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 0170F603E5 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=U/kuAjUgp3tQf2le0jr3N303rtmCYpDvjZGFp3cryig=; b=nmEWgQfCm8yevh qpThfvwQTntSbRdkawmJS7aNudOjaufatqPaKM5SAORIvgwJRKsEA2ahJf7Js5G/iUzo4rrX7hTlr p7LZ9AKotW3kmMBRSt0Hn2N32t05dphfmFrenfgB9AwY7dYzG0ELEyILJHPXN3xO9YFVJh13UWx+1 MclKGb245vBGE62NDWBp5wvjTqMJ21sBFFZgLcCpT+PAc9vJcxVLvOs6UQC5Tn6A1biAYgcCYlZn5 Y7CXRyckYCF3e1rwMoLZhFThmNv/19zVJvIEMX1bIog7fJ3Bp+44Ib7fF4FOYsVe7p/GTvXUL4Uou +MriyW1N00giUdO/vmKA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mTPtb-00BrH7-Cz; Thu, 23 Sep 2021 14:40:19 +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 1mTPsw-00Br9V-Lh for linux-arm-kernel@lists.infradead.org; Thu, 23 Sep 2021 14:39:41 +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 77719D6E; Thu, 23 Sep 2021 07:39:36 -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 27B303F718; Thu, 23 Sep 2021 07:39:35 -0700 (PDT) From: Suzuki K Poulose To: mathieu.poirier@linaro.org, linux-arm-kernel@lists.infradead.org Cc: anshuman.khandual@arm.com, mike.leach@linaro.org, leo.yan@linaro.org, coresight@lists.linaro.org, linux-kernel@vger.kernel.org, Suzuki K Poulose , Peter Zijlstra , Will Deacon Subject: [PATCH v4 4/5] coresight: trbe: End the AUX handle on truncation Date: Thu, 23 Sep 2021 15:39:18 +0100 Message-Id: <20210923143919.2944311-5-suzuki.poulose@arm.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20210923143919.2944311-1-suzuki.poulose@arm.com> References: <20210923143919.2944311-1-suzuki.poulose@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210923_073938_888998_0112E02D X-CRM114-Status: GOOD ( 15.41 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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, triggered from the kernel perf layer. 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 Reviewed-by: Anshuman Khandual Signed-off-by: Suzuki K Poulose --- drivers/hwtracing/coresight/coresight-trbe.c | 26 ++++++++++++-------- 1 file changed, 16 insertions(+), 10 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 0a9106c15639..4174300f1344 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -152,6 +152,7 @@ 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_output_end(handle, 0); *this_cpu_ptr(buf->cpudata->drvdata->handle) = NULL; } @@ -715,7 +716,7 @@ 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); @@ -739,9 +740,10 @@ 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) @@ -772,6 +774,7 @@ 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); @@ -796,24 +799,27 @@ 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; } -- 2.24.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel