From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (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 BFA4320DDB for ; Wed, 13 Mar 2024 20:56:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710363391; cv=none; b=QM3Eaa33tXZpEC+Fw54xzZOf7TbyLL84aFuuQV7FozDFAq4KQ9BrUWNansDnuvAVo/Y0/6iSYPaV9n7TYQGdirgvlYFtV1ffCsIyeDxQgQsFmP+j9Un0MzDLy3v8oUyqEkzRTwPy7mOF+zd6kx9Oreei02D0BREpWn3r3dFcFVo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710363391; c=relaxed/simple; bh=ombC87M/jDfVGex2UxCohkXM5I06cdOhxPkknjHKUX4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=b8zX3yIXjJ2x3drFUASXFHHp68x9tihdaIRpoUcHtVo6dDKCBf/HqKDSEINKkQMElrRFfJf45JuxHANivk/cnsQagtgka7LH/IT9FaU6WcprblfmOzSNcdHF+zgacFoJOmOMCvHEwh+pry3cu0vsfaTeZ3rqJntIJYLTaac1BTw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=L0Be1V/F; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="L0Be1V/F" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1710363381; bh=ombC87M/jDfVGex2UxCohkXM5I06cdOhxPkknjHKUX4=; h=From:To:Cc:Subject:Date:From; b=L0Be1V/F5E3uHHIK18kHDRKtGttorOPLvQ786BQ1vDLVwQAU05Ya82DAF7CFBXPVS HuQ+J1Y+UdsDAPfs7y4sXeCq3WhqkNVW0Q0d38ac0vdcJV6BMmm/1ZfkTSv7IGq897 BgIh5p3CPtbV+bC8wKW/4nm5GHeDUisQs8dptfHBz93bMQ0iDlSJJTowz3R5niePJ4 cBlmzbNd3BY8vz37TGu+zCsb1/lbkDkCpdAKhnXrA2wrCZHxcwYrZe8cUIDqzwvNcx frB9izs9s0woYijBIYQXGPtqZwswjaBLIufME2OgUboIHYqI9OdG4maLweULnokyTr w+YIp5+9m8ojg== Received: from thinkos.internal.efficios.com (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4Tw2qT3X1Dzjnn; Wed, 13 Mar 2024 16:56:21 -0400 (EDT) From: Mathieu Desnoyers To: Peter Oskolkov Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Peter Zijlstra , "Paul E . McKenney" , Boqun Feng , Andrew Hunter , Maged Michael , gromer@google.com, Avi Kivity , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Subject: [RFC PATCH 0/2] Introduce serialized smp_call_function APIs Date: Wed, 13 Mar 2024 16:56:20 -0400 Message-Id: <20240313205622.2179659-1-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit commit 944d5fe50f3f ("sched/membarrier: reduce the ability to hammer on sys_membarrier") introduces a mutex over all membarrier operations to reduce its ability to slow down the rest of the system. This RFC series has two objectives: 1) Move this mutex to the smp_call_function APIs so other system calls using smp_call_function IPIs are limited in the same way, 2) Restore scalability of MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ with MEMBARRIER_CMD_FLAG_CPU, which targets specific CPUs with IPIs. This may or may not be useful, and I would welcome benchmarks from users of this feature to figure out if this is worth it. This series applies on top of v6.8. Thanks, Mathieu Cc: Peter Zijlstra Cc: Paul E. McKenney Cc: Boqun Feng Cc: Andrew Hunter Cc: Maged Michael Cc: gromer@google.com Cc: Avi Kivity Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Peter Oskolkov Mathieu Desnoyers (2): smp: Implement serialized smp_call_function APIs sched/membarrier: Use serialized smp_call_function APIs include/linux/smp.h | 40 ++++++++++++++ kernel/sched/membarrier.c | 24 +++------ kernel/smp.c | 106 +++++++++++++++++++++++++++++++++----- 3 files changed, 141 insertions(+), 29 deletions(-) -- 2.39.2