From patchwork Wed Jan 17 14:47:03 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Graf X-Patchwork-Id: 13521851 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 051E6C47DA2 for ; Wed, 17 Jan 2024 14:50:57 +0000 (UTC) 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=yMBXyCk7L2APCuOUo2w+XmqDLyCws/15Ab1H/yzUgF0=; b=izNSdSempqE37L mwQ/RASY9vyZiUV524/qjUpsOTz2NTfLWc7QquSbW8uLk+dyaXl2jo/i/qeISB+Rg7ufJJXle6pT3 UCN/w50fn8eniv6xUWK1JCC7SLLt3GOgL9yIVne6kjNgWrasTDLLJaC8zcfQFa8LGftytVsScVom6 dbPvj6t8ppSTrT/lsDgpEf0jwkgAGbKU/RmrlUUVWb7fDDhocgqn2vQQ34LM5xv14sYqFSokFQr6h iRNiKzoYn61ZYX+AIALsAVPaAUivbvRAtZVnmLD4+9ErCCskXkAKeMAhp+aoQ3W75ME5+kQAyUx1X ROqleh17GUf4OvSjPXXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1rQ7FJ-00HJLA-1f; Wed, 17 Jan 2024 14:50:25 +0000 Received: from smtp-fw-9106.amazon.com ([207.171.188.206]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1rQ7F6-00HJ9N-2b; Wed, 17 Jan 2024 14:50:18 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1705503013; x=1737039013; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=K22H13Upw8ZJvq6V1e5pgkkFku3zAKlZ1ZPbskJJqpo=; b=SY/xaT2i20T4hrpzetlE1V0HFVckm5+tLUPrJfEIJk19tXYpiYqwI0iG Pfq16mALcaNfH6/ZbPe3RRQkqp+lZpzreg/O9xXNPwyT+Sdx7IJzwVX33 KxKnXwlXj3bPZPUgR06plYhZ/u1axC+vHRPYYWde5yKuSVUQ7EL09ivoq g=; X-IronPort-AV: E=Sophos;i="6.05,200,1701129600"; d="scan'208";a="697789089" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-pdx-2a-m6i4x-1197e3af.us-west-2.amazon.com) ([10.25.36.210]) by smtp-border-fw-9106.sea19.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Jan 2024 14:50:12 +0000 Received: from smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev (pdx2-ws-svc-p26-lb5-vlan2.pdx.amazon.com [10.39.38.66]) by email-inbound-relay-pdx-2a-m6i4x-1197e3af.us-west-2.amazon.com (Postfix) with ESMTPS id B58F8100FC5; Wed, 17 Jan 2024 14:50:03 +0000 (UTC) Received: from EX19MTAUWA001.ant.amazon.com [10.0.21.151:29526] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.41.57:2525] with esmtp (Farcaster) id bc9be742-cddd-4430-a2bc-c8966b4ce96c; Wed, 17 Jan 2024 14:50:03 +0000 (UTC) X-Farcaster-Flow-ID: bc9be742-cddd-4430-a2bc-c8966b4ce96c Received: from EX19D020UWC004.ant.amazon.com (10.13.138.149) by EX19MTAUWA001.ant.amazon.com (10.250.64.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Wed, 17 Jan 2024 14:50:02 +0000 Received: from dev-dsk-graf-1a-5ce218e4.eu-west-1.amazon.com (10.253.83.51) by EX19D020UWC004.ant.amazon.com (10.13.138.149) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.40; Wed, 17 Jan 2024 14:49:58 +0000 From: Alexander Graf To: CC: , , , , , , , Eric Biederman , "H . Peter Anvin" , Andy Lutomirski , Peter Zijlstra , Steven Rostedt , Andrew Morton , Mark Rutland , "Tom Lendacky" , Ashish Kalra , James Gowans , Stanislav Kinsburskii , , , , Anthony Yznaga , Usama Arif , David Woodhouse , Benjamin Herrenschmidt , Rob Herring , Krzysztof Kozlowski Subject: [PATCH v3 16/17] tracing: Add config option for kexec handover Date: Wed, 17 Jan 2024 14:47:03 +0000 Message-ID: <20240117144704.602-17-graf@amazon.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240117144704.602-1-graf@amazon.com> References: <20240117144704.602-1-graf@amazon.com> MIME-Version: 1.0 X-Originating-IP: [10.253.83.51] X-ClientProxiedBy: EX19D041UWB004.ant.amazon.com (10.13.139.143) To EX19D020UWC004.ant.amazon.com (10.13.138.149) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240117_065012_983073_7F2A2C26 X-CRM114-Status: GOOD ( 14.39 ) 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 Now that all bits are in place to allow ftrace to pass its trace data into the next kernel on kexec, let's give users a kconfig option to enable the functionality. Signed-off-by: Alexander Graf --- v1 -> v2: - Select crc32 --- kernel/trace/Kconfig | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 61c541c36596..418a5ae11aac 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -1169,6 +1169,20 @@ config HIST_TRIGGERS_DEBUG If unsure, say N. +config FTRACE_KHO + bool "Ftrace Kexec handover support" + depends on KEXEC_KHO + select CRC32 + help + Enable support for ftrace to pass metadata across kexec so the new + kernel continues to use the previous kernel's trace buffers. + + This can be useful when debugging kexec performance or correctness + issues: The new kernel can dump the old kernel's trace buffer which + contains all events until reboot. + + If unsure, say N. + source "kernel/trace/rv/Kconfig" endif # FTRACE