From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C6BDC4360C for ; Sun, 6 Oct 2019 17:20:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FBBD2077B for ; Sun, 6 Oct 2019 17:20:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382438; bh=QWG0Sgk+7RWxv4CesJTL0WSeRDiYchbm4cUUMDSl1a0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gwA1+nZfsXAzWIkhXosr1vrlWYlsVFpjtIFo/tVTjkN+U1MQH0lDRWkwb48V69qb6 x/2qNyC/Q4Lkffzcx6uWQtUOmP+5sz9YFI7f4LjGKdQ7DYcr9xLFFp6je3/fH9l4AE IwVXWtcY4xIc3B020sfKe8ifFjUXXMMSs+VOZ528= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727268AbfJFRUh (ORCPT ); Sun, 6 Oct 2019 13:20:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:45632 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727233AbfJFRUg (ORCPT ); Sun, 6 Oct 2019 13:20:36 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B48602080F; Sun, 6 Oct 2019 17:20:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570382436; bh=QWG0Sgk+7RWxv4CesJTL0WSeRDiYchbm4cUUMDSl1a0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tc2tsgS2/S1uR5sRip2RGiZ5mHxCkmEJ1CB9201So0Rgpav+g+B+WlPg4kbX+0/T5 3Vv1NrH1Rz3vI94X+rDTJxm+W1wHZ29BCZF8Qlcm8E0wYSZ6bHiE8G/mRtRU619HE5 jJDQWIw1vg772V7s0Fqgrke4L8BBybYdsD3qyLgU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Corey Minyard , Sasha Levin Subject: [PATCH 4.4 03/36] ipmi_si: Only schedule continuously in the thread in maintenance mode Date: Sun, 6 Oct 2019 19:18:45 +0200 Message-Id: <20191006171042.264521960@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191006171038.266461022@linuxfoundation.org> References: <20191006171038.266461022@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Corey Minyard [ Upstream commit 340ff31ab00bca5c15915e70ad9ada3030c98cf8 ] ipmi_thread() uses back-to-back schedule() to poll for command completion which, on some machines, can push up CPU consumption and heavily tax the scheduler locks leading to noticeable overall performance degradation. This was originally added so firmware updates through IPMI would complete in a timely manner. But we can't kill the scheduler locks for that one use case. Instead, only run schedule() continuously in maintenance mode, where firmware updates should run. Signed-off-by: Corey Minyard Signed-off-by: Sasha Levin --- drivers/char/ipmi/ipmi_si_intf.c | 24 +++++++++++++++++++----- 1 file changed, 19 insertions(+), 5 deletions(-) diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c index 2f9abe0d04dcb..2f8ff63bbbe43 100644 --- a/drivers/char/ipmi/ipmi_si_intf.c +++ b/drivers/char/ipmi/ipmi_si_intf.c @@ -281,6 +281,9 @@ struct smi_info { */ bool irq_enable_broken; + /* Is the driver in maintenance mode? */ + bool in_maintenance_mode; + /* * Did we get an attention that we did not handle? */ @@ -1091,11 +1094,20 @@ static int ipmi_thread(void *data) spin_unlock_irqrestore(&(smi_info->si_lock), flags); busy_wait = ipmi_thread_busy_wait(smi_result, smi_info, &busy_until); - if (smi_result == SI_SM_CALL_WITHOUT_DELAY) + if (smi_result == SI_SM_CALL_WITHOUT_DELAY) { ; /* do nothing */ - else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) - schedule(); - else if (smi_result == SI_SM_IDLE) { + } else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait) { + /* + * In maintenance mode we run as fast as + * possible to allow firmware updates to + * complete as fast as possible, but normally + * don't bang on the scheduler. + */ + if (smi_info->in_maintenance_mode) + schedule(); + else + usleep_range(100, 200); + } else if (smi_result == SI_SM_IDLE) { if (atomic_read(&smi_info->need_watch)) { schedule_timeout_interruptible(100); } else { @@ -1103,8 +1115,9 @@ static int ipmi_thread(void *data) __set_current_state(TASK_INTERRUPTIBLE); schedule(); } - } else + } else { schedule_timeout_interruptible(1); + } } return 0; } @@ -1283,6 +1296,7 @@ static void set_maintenance_mode(void *send_info, bool enable) if (!enable) atomic_set(&smi_info->req_events, 0); + smi_info->in_maintenance_mode = enable; } static const struct ipmi_smi_handlers handlers = { -- 2.20.1