From nobody Sun Nov 24 20:50:01 2024 Received: from msa.smtpout.orange.fr (out-68.smtpout.orange.fr [193.252.22.68]) (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 A9FE01E2828; Fri, 1 Nov 2024 21:49:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.252.22.68 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730497748; cv=none; b=RViMq2I4+OezglbPpx+wG9JVYqPgWa2LYLNwDCRdUHX4qujAl1lAC70B5hN8JUZO/30BPyvnO0X7VJ+Nczqusws6K6GWEGz8rFrWU/4yYaawSnVq/nOeBYPdyfmoGjmRbAszihdOl8Np06u0Sp7cXe6jOzwtOx7dpoE28R68LCU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730497748; c=relaxed/simple; bh=lOOo4ZXdmdikkhGGJEt2LgdpZPz5E/NO8DC+U+ixe3Q=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Rpi7fOj2j4m8ygsEbfjl36nffmHsmQi0xUo7xp1bXQEkmID1XJCAWPOfExn/+AmW4uuP8tnrlb34O1tDYnGzCfRZSoSEqRhWwD3PjzVTIErVt7/Q9daS0ZKB9yLkr5olChFAKGw8B0pCeaMKuc/aeQNHsMZFnvKawi4O3tNmJ8A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wanadoo.fr; spf=pass smtp.mailfrom=wanadoo.fr; dkim=pass (2048-bit key) header.d=wanadoo.fr header.i=@wanadoo.fr header.b=h7g00QC+; arc=none smtp.client-ip=193.252.22.68 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=wanadoo.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wanadoo.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=wanadoo.fr header.i=@wanadoo.fr header.b="h7g00QC+" Received: from localhost.localdomain ([90.11.132.44]) by smtp.orange.fr with ESMTPA id 6yxjtTrloA7fH6yxktswpK; Fri, 01 Nov 2024 22:13:45 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wanadoo.fr; s=t20230301; t=1730495625; bh=EYi+7zxC4m12VG02hrYZtY36xLPuD6WgT3l4MPN+hD4=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=h7g00QC+zuN+TfEujN3s0xj8P9ecv5kWshswogVhEBqlPfZh/5/INCFkppQxLjtaK J/yQKYKmTRBZ/+zEKj/SEqMKUCMBhs8diO8eXo8ZdhhGaspr1SGriH8XxBZgittLdM JYjl4pMkaV3lDjm5FCfjJ52YL7lxfUU7Ns3TQ/chqT0TUnveQcZ5hLQS6Jc5TWBaid jzH8KS/maKtrVap8iEYlvhwSXs36KaWLjtzF6+imsOyseL2lecsek6QevAiErLt8nF +9z7IzsNJJIf5McHQAjPl1MjUcl5PlhHaUz3jL538KD8aWGhxHaO4W+KPyzB+vambK GYv1+9O7lX8Hg== X-ME-Helo: localhost.localdomain X-ME-Auth: Y2hyaXN0b3BoZS5qYWlsbGV0QHdhbmFkb28uZnI= X-ME-Date: Fri, 01 Nov 2024 22:13:45 +0100 X-ME-IP: 90.11.132.44 From: Christophe JAILLET To: Masami Hiramatsu , Oleg Nesterov , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET , linux-trace-kernel@vger.kernel.org Subject: [PATCH] uprobes: Re-order struct uprobe_task to save some space Date: Fri, 1 Nov 2024 22:13:33 +0100 Message-ID: X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" On x86_64, with allmodconfig, struct uprobe_task is 72 bytes long, with a hole and some padding. /* size: 72, cachelines: 2, members: 7 */ /* sum members: 64, holes: 1, sum holes: 4 */ /* padding: 4 */ /* forced alignments: 1, forced holes: 1, sum forced holes: 4 */ /* last cacheline: 8 bytes */ Reorder the structure to fill the hole and avoid the padding. This way, the whole structure fits in a single cacheline and some memory is saved when it is allocated. /* size: 64, cachelines: 1, members: 7 */ /* forced alignments: 1 */ Signed-off-by: Christophe JAILLET Acked-by: Masami Hiramatsu (Google) --- Compile tested only --- include/linux/uprobes.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index dbaf04189548..c684a470477f 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -73,6 +73,9 @@ enum uprobe_task_state { struct uprobe_task { enum uprobe_task_state state; =20 + unsigned int depth; + struct return_instance *return_instances; + union { struct { struct arch_uprobe_task autask; @@ -89,9 +92,6 @@ struct uprobe_task { unsigned long xol_vaddr; =20 struct arch_uprobe *auprobe; - - struct return_instance *return_instances; - unsigned int depth; }; =20 struct return_consumer { --=20 2.47.0