From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-172.mta0.migadu.com (out-172.mta0.migadu.com [91.218.175.172]) (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 015D9278E77 for ; Tue, 5 Aug 2025 15:49:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754408950; cv=none; b=nXrXHNt3NuDyuIckI6/X+VPWcIIHakTnpXOrCmbgElN+Tv8j1WhYzUaGymebI9LZcybOnF/YxBAuJRMFYLACNQqR/uotzYHzxSp2K6OW4m/KXuSFh6GIhWaVog8ffYSxtI5i7xw/0rs7iavV5hQl6V+Eg8J7bzvehWEgtDAWke8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754408950; c=relaxed/simple; bh=X2dfIZZ5Mq2RqlPfGxGJ4bSfulRv0axO5u2AT+yBECE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=MuXaGTjbCRmcwOddqjfH4TmqMwDTKzq0RAQKpCFbqV36c6V4cHtW6cDFHo53iXI7XIiUdD7hOhcLvQ+qyo5vI/yY9TDhQvnJJgk/14ksz/otd6ooydynR+AOb1XKcdZuseB33Qs65LZ+7WpR/ILb+2EjjtvWBLbHleWgdXgre/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=AgI9ANK2; arc=none smtp.client-ip=91.218.175.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="AgI9ANK2" Message-ID: <4348a5c5-8689-49a8-b59f-bf4ab2bbc74b@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1754408934; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=X2dfIZZ5Mq2RqlPfGxGJ4bSfulRv0axO5u2AT+yBECE=; b=AgI9ANK2dvdpxoFYlMskbC/MdROFC6Z8+fUVSU/pLKWFrXrBrM0kSG+OU3rc7IKb1YTI+4 kZ9tuoe5njMBhmW4xumfuFoTCtt3ry2E4nektzKuP6rPaagoLAjQ2DwNMJq2WPWRhFTUaZ TnjE6NP0M8gqHz/7ysKBAepmQ6Rr5B4= Date: Tue, 5 Aug 2025 08:48:47 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH bpf-next] bpf: Remove migrate_disable in kprobe_multi_link_prog_run Content-Language: en-GB To: Tao Chen , song@kernel.org, jolsa@kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, mattbobrowski@google.com, rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org References: <20250805122312.1890951-1-chen.dylane@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: <20250805122312.1890951-1-chen.dylane@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 8/5/25 5:23 AM, Tao Chen wrote: > bpf program should run under migration disabled, kprobe_multi_link_prog_run > called the way from graph tracer, which disables preemption in > function_graph_enter_regs, as Jiri and Yonghong suggested, there is no > need to use migrate_disable. As a result, some overhead maybe will be > reduced. > > Fixes: 0dcac2725406 ("bpf: Add multi kprobe link") > Signed-off-by: Tao Chen Acked-by: Yonghong Song