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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 481ABC7618F for ; Thu, 18 Jul 2019 21:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1F61E21019 for ; Thu, 18 Jul 2019 21:14:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391001AbfGRVOH (ORCPT ); Thu, 18 Jul 2019 17:14:07 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:55874 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727767AbfGRVOH (ORCPT ); Thu, 18 Jul 2019 17:14:07 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::d71]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 29B831528342B; Thu, 18 Jul 2019 14:14:06 -0700 (PDT) Date: Thu, 18 Jul 2019 14:14:05 -0700 (PDT) Message-Id: <20190718.141405.1070121094691581998.davem@davemloft.net> To: ldv@altlinux.org Cc: hch@lst.de, khalid.aziz@oracle.com, torvalds@linux-foundation.org, akpm@linux-foundation.org, matorola@gmail.com, sparclinux@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 09/16] sparc64: use the generic get_user_pages_fast code From: David Miller In-Reply-To: <20190717215956.GA30369@altlinux.org> References: <20190625143715.1689-1-hch@lst.de> <20190625143715.1689-10-hch@lst.de> <20190717215956.GA30369@altlinux.org> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 18 Jul 2019 14:14:06 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Dmitry V. Levin" Date: Thu, 18 Jul 2019 00:59:56 +0300 > So this ended up as commit 7b9afb86b6328f10dc2cad9223d7def12d60e505 > (thanks to Anatoly for bisecting) and introduced a regression: > futex.test from the strace test suite now causes an Oops on sparc64 > in futex syscall. > > Here is a heavily stripped down reproducer: Does not reproduce for me on a T4-2 machine. So this problem might depend on the type of system you are on, I suspect it's one of those "pre-Niagara vs. Niagara and later" situations because that's the dividing line between two set of wildly different TLB and cache management methods. What kind of machine are you on?