From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99100437844 for ; Tue, 21 Jul 2026 10:36:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784630185; cv=none; b=KnGBdbgo8YPZUarNWeKOgWalxIfaCouW+gw0T2NYzX99QNFlRISNWxWAlMZR04Yqmh2S/lhUD3p1J1wrQYkRFc9+we1z0P/NGRC6Hk4sBfKXDZAWED7YLfC3++HKttVAQvABhRwsbT3Cfpi3d56pAU/UBI2xxHITuIbp9fWuOrg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784630185; c=relaxed/simple; bh=UBal+MUspsHlq0J61JV2zjLILte2l5BRU+SUqJaNMqc=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=o5zaXrFXYqcjsB2A9C84kJu43iU5NmGJxUUAZTu8vMLFYBwFju1ViNrCfKj3lobliVgmI+WLKm0Bg/a2XeWMxXNYV5MubV/vahK+GTlN6fFR7YDrNxKTC2RM8a+IB6O9ptJEXfPSqhuhHNwx2F+eJxDcsjaXOqNBOLCZTyrWTz8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=kMSMpHCe; arc=none smtp.client-ip=209.85.128.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--vdonnefort.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="kMSMpHCe" Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-4954dcd6131so35998225e9.3 for ; Tue, 21 Jul 2026 03:36:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784630181; x=1785234981; darn=vger.kernel.org; h=content-type:cc:to:from:subject:message-id:mime-version:date:from :to:cc:subject:date:message-id:reply-to:content-type; bh=F2vHuF7qw3o+XDYk1bRfnFG/zmMo9aEJv5/fWrgkpCg=; b=kMSMpHCekt87+jrnTxPFeOGO/v/6qOfsQv8x0jX/Z09h4YA/pu7+HJhnlC9z2ipM9G Oq7pA7IuC/RyQSr2j4e3ke7uvRXhOfCBRu6LiJ3QYrSsZhveH3+X9nuBalnHxa9Nt4Sd lkHwSJ84raY11j+J008JG9Ag7ba6Wi9pYdMa7zF0IgKQwpPw5QazCn1PyTdUupLkfAYb ce5vsvWP3xMSyomoNuyHWAJbmHzWaNPz6P6PHOylwuFCTrljjSmKsz/thlrh+AWKGYw9 mFfk/d4foKszKHrNDSqowCIkjr2iJz42zCyA05bzTU/N7nJRHFfPi/Y5WTDwjjAsTt3A +kmQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784630181; x=1785234981; h=content-type:cc:to:from:subject:message-id:mime-version:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=F2vHuF7qw3o+XDYk1bRfnFG/zmMo9aEJv5/fWrgkpCg=; b=Htey04eR3DtYQwQkfWFFIgwitoN/NofhxM8DWdiWfVrCUy6oYiGtOONup5YE5R3Jks 1NZDYD/ls4hjKUFhtFb8jFG6R7TLf1iM5w4VU54nrIPYtCpZQiLMipU/MsxFi/mRbj3x mSU/7byQTAcnnbYbGvVcUga7Qpz4plJEle+NXpVM3zDAvL7yFhEyPNdRUMak+xWhkxtW 48LR5RzTyeeq6r9aQLrcCEYTCsYwKIujt4tBirQJwV3LIwvA9G+dcDhYhzh6hVKYkg51 ZdyP9x5c3Sz3j7ascZf+e9YKU9qN7VBk0fj8t+zhJjMrnFNxIFI6MPjLlqPFKQEvduGm KeLg== X-Forwarded-Encrypted: i=1; AHgh+Rq5Fkm4ElfeT72rDUgsCsNQNPS8MV93hXSTl9ypHDueFpOv6WiWuKuRUji4bvYV1BGWvVox4W2MDRsopnn7CdZVQbQ=@vger.kernel.org X-Gm-Message-State: AOJu0YwSvqw/bm7fmE3QuKTqJ8XOFgVm+x0rfKylARaSLGbFPgNaAvF3 FxGJVCIBpDZXcjpmNy+u9sqeKsf3F12ONdKSqoUTzo0AEsyou9i0H2/olF0WnGw6+7iOeXAGYb1 XdTh82DSe2w2VDGd0xUm4Gg== X-Received: from wmpj5.prod.google.com ([2002:a05:600c:4885:b0:493:b328:830b]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1548:b0:493:c062:a533 with SMTP id 5b1f17b1804b1-4954a3e8fe1mr204300545e9.17.1784630180542; Tue, 21 Jul 2026 03:36:20 -0700 (PDT) Date: Tue, 21 Jul 2026 11:35:45 +0100 Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.55.0.229.g6434b31f56-goog Message-ID: <20260721103603.342266-1-vdonnefort@google.com> Subject: [PATCH v3 00/18] tracing/remotes: Add printk, dump_on_panic and boot parameters From: Vincent Donnefort To: rostedt@goodmis.org, mhiramat@kernel.org, linux-trace-kernel@vger.kernel.org Cc: mathieu.desnoyers@efficios.com, kernel-team@android.com, linux-kernel@vger.kernel.org, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" This series extends the recently introduced trace remotes infrastructure, bringing useful features for developers: * dump_on_panic: Dump the trace remote buffer on system panic. * dmesg: Redirect remote events to dmesg. * trace_remote=: Configure a trace_remote from the commandline. * poll_ms: Modify the polling period. It also brings a couple of optimisations: * In-header compressed length support for small events. * Single work thread for remote polling. And some misc improvements: * Use kstrtobool where possible * Free resources on remote registration failure v3: * Make sure dmesg and panic handlers are using null-terminated trace_seq. * Make struct trace_remote more compact * Fix dump_on_panic test unloaded case (Sashiko) * Rebase on 7.2-rc4 v2 (https://lore.kernel.org/all/20260605163825.1762953-1-vdonnefort@google.com/): Sashiko had a few spot-on comments on the v1 which forced me to heavily re-arrange the series, so I thought it'd be alright to send a v2 already including those changes. * dump_on_oops -> dump_on_panic * printk -> dmesg * Allow to configure poll_ms * Make the ring_buffer_iter functions panic-friendly * Gate tracefs .open on remote registration (Sashiko) * Use irqsave for reader lock (Sashiko) * Fix iter locking for TRI_DMESG (Sashiko) * Yield in the dmesg work (Sashiko) v1 (https://lore.kernel.org/all/20260602171146.2238998-1-vdonnefort@google.com/) Vincent Donnefort (18): tracing/remotes: Gate tracefs files opening on trace remote registration tracing/remotes: Release tracefs,eventfs on registration failure tracing/remotes: Use kstrtobool for boolean tracefs files tracing/remotes: Use a single per-remote polling work tracing/simple_ring_buffer: Add support for compressed length tracing/remotes: Add dmesg tracefs file tracing/remotes: selftests: Add a test for the dmesg tracefs file tracing/remotes: selftests: Prefix hypervisor folder ring-buffer: Use irqsave for the reader lock in ring_buffer_poll_remote ring-buffer: Use panic-friendly locking in ring_buffer_iter interface ring-buffer: Add ring_buffer_read_remote_meta_page() ring-buffer: Add kerneldoc for ring_buffer_poll_remote tracing/remotes: Add dump_on_panic tracefs file tracing/remotes: selftests: Add a test for the dump_on_panic tracefs file tracing/remotes: Add poll_ms tracefs file tracing/remotes: Add trace_remote cmdline options Documentation: tracing/remotes: Add detailed tracefs layout Documentation/kernel-parameters: Add trace_remote .../admin-guide/kernel-parameters.txt | 19 + Documentation/trace/remotes.rst | 66 +- include/linux/ring_buffer.h | 1 + kernel/trace/ring_buffer.c | 88 +- kernel/trace/simple_ring_buffer.c | 25 +- kernel/trace/trace_remote.c | 825 +++++++++++++++--- .../buffer_size.tc | 0 .../test.d/remotes/00hypervisor/dmesg.tc | 11 + .../remotes/00hypervisor/dump_on_panic.tc | 11 + .../{hypervisor => 00hypervisor}/hotplug.tc | 0 .../{hypervisor => 00hypervisor}/reset.tc | 0 .../{hypervisor => 00hypervisor}/trace.tc | 0 .../trace_pipe.tc | 0 .../{hypervisor => 00hypervisor}/unloading.tc | 0 .../selftests/ftrace/test.d/remotes/dmesg.tc | 72 ++ .../ftrace/test.d/remotes/dump_on_panic.tc | 51 ++ .../selftests/ftrace/test.d/remotes/functions | 2 + 17 files changed, 1031 insertions(+), 140 deletions(-) rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/buffer_size.tc (100%) create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dmesg.tc create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/00hypervisor/dump_on_panic.tc rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/hotplug.tc (100%) rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/reset.tc (100%) rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/trace.tc (100%) rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/trace_pipe.tc (100%) rename tools/testing/selftests/ftrace/test.d/remotes/{hypervisor => 00hypervisor}/unloading.tc (100%) create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/dmesg.tc create mode 100644 tools/testing/selftests/ftrace/test.d/remotes/dump_on_panic.tc base-commit: 1590cf0329716306e948a8fc29f1d3ee87d3989f -- 2.55.0.229.g6434b31f56-goog