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: 763778 Received: from smtp-fw-9106.amazon.com (smtp-fw-9106.amazon.com [207.171.188.206]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEC5B2233E; Wed, 17 Jan 2024 14:50:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=207.171.188.206 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705503014; cv=none; b=GsMI7zn00Dxoffnqh+WS0NB/e4pWzDJLzDSXChqEWlf74CgsZUi11QEvDIN6bMAdy9caFRIuaOW/7TPKx1OZy9QdxmhqfNfdTg3fCYv8WDH7pCIJCY7eIY+iYxq2rao4bTYQ7dSb4GomcsGol7Rn+VJvw03s9MBibJheFure8MA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705503014; c=relaxed/simple; bh=UUfJqxwzaJfKgat15q/d3JONEvY5L8ZpIJR57kcne6I=; h=DKIM-Signature:X-IronPort-AV:Received:Received:Received: X-Farcaster-Flow-ID:Received:Received:From:To:CC:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: X-Originating-IP:X-ClientProxiedBy:Content-Type: Content-Transfer-Encoding; b=BJHvZqRhnG07OAsiFa+gPPSrhdWH6IVpqHbtbop8t94nsVh9EzCfwaY7b9YN4tqnGDyQgC3vQQg8zP3JKAns7grNGTf9g4kcmn2iJxuFf0NQtItdku2gHk/ImoJiC6DYcpqfNWdfykijpetUFO7RXqxjliBvcMI6NE+lZCU+TgQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.de; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=SY/xaT2i; arc=none smtp.client-ip=207.171.188.206 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="SY/xaT2i" 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> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: EX19D041UWB004.ant.amazon.com (10.13.139.143) To EX19D020UWC004.ant.amazon.com (10.13.138.149) 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