From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f200.google.com (mail-pf0-f200.google.com [209.85.192.200]) by kanga.kvack.org (Postfix) with ESMTP id B25B26B0038 for ; Tue, 24 Jan 2017 17:36:01 -0500 (EST) Received: by mail-pf0-f200.google.com with SMTP id e4so126490122pfg.4 for ; Tue, 24 Jan 2017 14:36:01 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id h82si20959988pfj.218.2017.01.24.14.36.00 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 24 Jan 2017 14:36:00 -0800 (PST) Date: Tue, 24 Jan 2017 14:35:59 -0800 From: Andrew Morton Subject: Re: [PATCH 01/12] uprobes: split THPs before trying replace them Message-Id: <20170124143559.57cea7092a2efff940aeeef0@linux-foundation.org> In-Reply-To: <20170124222217.GB19920@node.shutemov.name> References: <20170124162824.91275-1-kirill.shutemov@linux.intel.com> <20170124162824.91275-2-kirill.shutemov@linux.intel.com> <20170124132849.73135e8c6e9572be00dbbe79@linux-foundation.org> <20170124222217.GB19920@node.shutemov.name> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , Andrea Arcangeli , Hugh Dickins , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Oleg Nesterov , Peter Zijlstra On Wed, 25 Jan 2017 01:22:17 +0300 "Kirill A. Shutemov" wrote: > On Tue, Jan 24, 2017 at 01:28:49PM -0800, Andrew Morton wrote: > > On Tue, 24 Jan 2017 19:28:13 +0300 "Kirill A. Shutemov" wrote: > > > > > For THPs page_check_address() always fails. It's better to split them > > > first before trying to replace. > > > > So what does this mean. uprobes simply fails to work when trying to > > place a probe into a THP memory region? > > Looks like we can end up with endless retry loop in uprobe_write_opcode(). > > > How come nobody noticed (and reported) this when using the feature? > > I guess it's not often used for anon memory. OK, can we please include discussion of these things in the changelog? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org