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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 888D4C35640 for ; Fri, 21 Feb 2020 08:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55DC2206DB for ; Fri, 21 Feb 2020 08:44:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582274647; bh=wIqsMrdKLb+D/TuHlWfbWthZCsYzOhhbmcyKf/OfsBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YJpvPdqZT9+iQ8pUKx1Cs+GV6/8qvQNqUHhfx5HX52appjOwU91sbG9ZkZLhsQKnO /+pyLVo5JiQSSqcInxmnKQGehAAmuER5y/FaOiXybOLKFRrNdfjl1bgNA+DW6UyJ1w sMSQ4ZRgTN102jH64/tVgt9keHz0Cj+0UgrB2xYs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729763AbgBUHws (ORCPT ); Fri, 21 Feb 2020 02:52:48 -0500 Received: from mail.kernel.org ([198.145.29.99]:50814 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728953AbgBUHws (ORCPT ); Fri, 21 Feb 2020 02:52:48 -0500 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 0EA1520578; Fri, 21 Feb 2020 07:52:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582271567; bh=wIqsMrdKLb+D/TuHlWfbWthZCsYzOhhbmcyKf/OfsBY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XxtxnbKRaTchZ+GT+iyTOrykgJxoGu13kszGDX6+N9CQY7iPmixZc3Utsy/P0+gH7 YiIW0T2glPiotyJaU4WbNfXo0zHUEcHM6iRJqgpCV8q1lT+t2ch620rgS1AmEA35ZM DN4aAPQBPnqEX8yVOlSV/R1+eVwewoAGBX4hrND8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Adhemerval Zanella , Arnd Bergmann , Saeed Mahameed , Sasha Levin Subject: [PATCH 5.5 215/399] mlx5: work around high stack usage with gcc Date: Fri, 21 Feb 2020 08:39:00 +0100 Message-Id: <20200221072423.900172139@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072402.315346745@linuxfoundation.org> References: <20200221072402.315346745@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: Arnd Bergmann [ Upstream commit 42ae1a5c76691928ed217c7e40269db27f5225e9 ] In some configurations, gcc tries too hard to optimize this code: drivers/net/ethernet/mellanox/mlx5/core/en_stats.c: In function 'mlx5e_grp_sw_update_stats': drivers/net/ethernet/mellanox/mlx5/core/en_stats.c:302:1: error: the frame size of 1336 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] As was stated in the bug report, the reason is that gcc runs into a corner case in the register allocator that is rather hard to fix in a good way. As there is an easy way to work around it, just add a comment and the barrier that stops gcc from trying to overoptimize the function. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92657 Cc: Adhemerval Zanella Signed-off-by: Arnd Bergmann Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/en_stats.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c index 9f09253f9f466..a05158472ed11 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_stats.c @@ -297,6 +297,9 @@ static void mlx5e_grp_sw_update_stats(struct mlx5e_priv *priv) s->tx_tls_drop_bypass_req += sq_stats->tls_drop_bypass_req; #endif s->tx_cqes += sq_stats->cqes; + + /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92657 */ + barrier(); } } } -- 2.20.1