From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) (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 F043E42DFF5; Mon, 13 Jul 2026 14:29:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=216.40.44.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783952983; cv=none; b=iErLL7jdA468bFCUpGYUGl4XJudmf7V3CODdHjTNtB8DvjxRxcUs+7qWSPKA4npnBP+ulScTRy/6FqTqgV39ac/NHsNGBO+gN5/PKe32cVgkYMY+7veIdrNqZpChZW+Uk515IWIvafrLSl5pIF9cjZsACaoI9QCYbnVQVgQE2Uc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783952983; c=relaxed/simple; bh=Zc0pb295FxTx+p+5rA2U6FezXMgvUCpI5IcbT+Quidk=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xv/+Ejv3tUSLwqy7nSforEZSTmnVKHzjyTr6JpyPNf8KES7o+hdiVW2klIbDRc8cqfz0zUOo4n9o/7BHs9spqt7pVGud8rFKGv6hEy9t+fuYymHjutbEqcGy9ZhCMk1E5ZsfSp+6O9TMK/q5MfW1ARhawj99Z1WUr5VTjbQH1WY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org; spf=pass smtp.mailfrom=goodmis.org; arc=none smtp.client-ip=216.40.44.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=goodmis.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=goodmis.org Received: from omf18.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 585F1140182; Mon, 13 Jul 2026 14:23:44 +0000 (UTC) Received: from [HIDDEN] (Authenticated sender: rostedt@goodmis.org) by omf18.hostedemail.com (Postfix) with ESMTPA id 6A16F2E; Mon, 13 Jul 2026 14:23:42 +0000 (UTC) Date: Mon, 13 Jul 2026 10:23:43 -0400 From: Steven Rostedt To: "Masami Hiramatsu (Google)" Cc: Jeongho Choi , linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org, ji2yoon.jo@samsung.com, minki.jang@samsung.com, hajun.sung@samsung.com Subject: Re: [BUG] tracing: Too many tries to read user space Message-ID: <20260713102343.74baba5b@gandalf.local.home> In-Reply-To: <20260713121659.6c8549331474337511c4f442@kernel.org> References: <20260708123753.GB1386@KORCO121415.samsungds.net> <20260710122231.9bc9fae3dcfc72215f4a2dcd@kernel.org> <20260710083357.49e05ff6@gandalf.local.home> <20260713121659.6c8549331474337511c4f442@kernel.org> X-Mailer: Claws Mail 3.20.0git84 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: 8ihbmxdwerw519jd1br4ux6kfttdcjqy X-Rspamd-Server: rspamout02 X-Rspamd-Queue-Id: 6A16F2E X-Session-Marker: 726F737465647440676F6F646D69732E6F7267 X-Session-ID: U2FsdGVkX19j+2viTIVFKuXNv0kXF4pjH1Fr2n/lfHE= X-HE-Tag: 1783952622-739595 X-HE-Meta: U2FsdGVkX1/+vBPI06538byEyAnTzfCbJEEY71yFOlN8Copwm8FRZk7SLm1/E/3v56f7vMHo+5gGgtziu5YNhFCGWAiEf1SssRzJkKPlcBeV/Oo3752O0LLrE+m0Ox9YqMqpzIL6NTyLnnS9eaNM/W+ozKAtGvCd6AFQXYVdTISRBJPquMQwyjALAayb+PybThBsgX66eMyiALB9LWynXubHm6CNXlYv/Pa6rF17MhfxBbcss29yu+3EJdynnE2jWT/Qm+CacyIjNFoKNN8WotGKvxya5sfVb1CxXX2n9Sn25L9bO+vAowQkzSeO1f/u8gtGGa2p8XX6EPsa11UsWgV0aIkZqj8BgcUjdKDEsgIhFjwNrUzdFw== On Mon, 13 Jul 2026 12:16:59 +0900 Masami Hiramatsu (Google) wrote: > > I also kept this around in case it was needed. Looks like it may be needed. > > Hmm, it's not clear whether this is the result of a scheduling storm > caused by kernel threads. But maybe worth to try. I don't see what else it could be. > > Jeongho, can you try this patch? Or/and you maybe also try using > mlock the LMKD process memory which is passed to trace_marker. Yes, Jeongho, can you please test this patch and also see if mlocking the memory used by trace_marker would help too? -- Steve