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 499883769E7 for ; Fri, 16 Oct 2026 15:47:14 +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=1792165637; cv=none; b=YQQq6uBCJ1C1QJVfWGz3htes8vMwRmJz4egZeYQuttgmDO+Mz4sptTPaQuc70xU44eYFCKcf6zACN4nuXLg/edyQrbP/Xhp+u6Vzeva2ioZrUMTwDNHJknVMzjHNR+DV249/girGy5e33xriKw5xNN1V9DwHeIm1FPrCMndcQUw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792165637; c=relaxed/simple; bh=m/WWeFMJCrVGffwdMiKasd9xCWFIQH8QaNE4CBT7ZC0=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=Rlbl8if9iom1R8U2+6HKceaYNSO4h/Wbf758QEBTh8AMXDAyqAuqQcl4nAdTAfhTspwXFqIEMoO47sg0VvXQVmVd1pgbTg0+JydI6it7kK7FKAnF0++v9QwQ5XJTGltjhvf7iz3Xx6owc/9mScWUUtMc9ix0sBR3SEzh0c2+JvA= 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=ekhd9zlw; 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="ekhd9zlw" Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-4a1721559b4so941125e9.1 for ; Fri, 16 Oct 2026 08:47:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1792165632; x=1792770432; 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=tELJHcWYoIhgNUw8lDudD6kd7E8RuUtrVQulu2IZ7CY=; b=ekhd9zlwWXDP/sKPZ9kOhG5L93ZNzR27Elucsp90KDH7YIWX2pm9VdJUBLkrKigHTy kibM/RZHo5MdPAqnMZDinZAd24+i/5cWRjyZPSuyTvCLVUUEHgLo73EzUMHvSWdEEiBY BnKQVMCskjjJFvZ49uLVTVzzBjGD78KgTD49EzHOcE0tPORwruwg5eZRvZaYkUIj/vXL S4mR6lFoGssh+d/dz/eJapK0NEbJcnmHORlSlq3EuLR1UuXFsNxOOfZLBClVLmmmbviO fQNJhk7tpBSgCKFQ3/o2h9png0Aafm6S4oUa5EEKsHkHPNPBZjNPWyEOaChKRqCr4xAy 4GfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792165632; x=1792770432; 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=tELJHcWYoIhgNUw8lDudD6kd7E8RuUtrVQulu2IZ7CY=; b=2UEy0hqOajXCxPv8Y7K4IGwXA2kU+mdXTziYynsE9pDcNIkSBPDK1ZUQrE2TkuSdSk z18x79SULMZDa2c+xpZqOEK0yluweKO4M7AL1LEkgm8gCvzhJHChskYuu4sNmiG4DGZ1 aj4cVkqJwyQD1h+95chBUOtItEZmtncfXG9jweCHN+qfX/0mkbqijZMS1CN8L3FzmKuS +6XjkH1S4auFHvnA8DNMSWVA2i2Kf1x23FL/gEtPNHQRVrYWdky58l3+8IJbYV1uWI97 9iC+HaoOv0FMri6UWyCb6mvRECnHTRU70DGXmPRgcQ1K03JLoNls2oXYxUc2WoOsQgiG 6yiA== X-Forwarded-Encrypted: i=1; AKwUvByRfRIAhmQ7k1Y08O9V4IFzY1GbOT+UBOFgqLQPpK+u7nlJixDAeJoj6JBZYuR0RTOuoST51dqyaz12389/LWBT0VY=@vger.kernel.org X-Gm-Message-State: AFq9FYJTNTutbX7Mus8bfSHqyLMb1K/1ffkjaZz+4ThTyID/sU3qLJBR eTBVXBuS8P233UWT7NdR4lAROrNJMtUJoLY745Uc3vy2GPk+WlcBYSOZjU/2DqWxo/39LDztazf r4rSl8/PO3/Iyxh3naxTp7A== X-Received: from wmee11.prod.google.com ([2002:a05:600c:218b:b0:4a1:950e:148b]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:1d10:b0:4a1:6992:f861 with SMTP id 5b1f17b1804b1-4a1d75ce2e7mr5304445e9.1.1792165632352; Fri, 16 Oct 2026 08:47:12 -0700 (PDT) Date: Fri, 16 Oct 2026 16:47:07 +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 2.56.0.176.g3575e65682-goog Message-ID: <20261016154707.2125747-1-vdonnefort@google.com> Subject: [PATCH v1] ring-buffer: Use is_user_task() in __rb_allocate_pages() 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" Before allocating ring buffer pages, __rb_allocate_pages() checks the available memory with si_mem_available(). This is however only a rough estimate and may report memory that can't be used for this allocation. In the event of an OOM, we don't want to penalise another task with the OOM killer, so the allocating thread is marked as the OOM origin when it is a user task. Checking current->mm is however not sufficient to distinguish user from kernel tasks. Instead, use is_user_task(). Suggested-by: Steven Rostedt Signed-off-by: Vincent Donnefort --- kernel/trace/ring_buffer.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9c4e40847e43..bcc28d50c634 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -2468,7 +2468,7 @@ static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, if (i < (nr_pages << subbuf_order)) return -ENOMEM; - user_thread = current->mm != NULL; + user_thread = is_user_task(current); } /* base-commit: c47a7b11bcb3d45e29723afcf6336866476b1d08 -- 2.56.0.176.g3575e65682-goog