From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sat, 05 Mar 2016 02:06:15 +0100 (CET) Received: from mailapp01.imgtec.com ([195.59.15.196]:8804 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27008358AbcCEBGM1dohm (ORCPT ); Sat, 5 Mar 2016 02:06:12 +0100 Received: from HHMAIL01.hh.imgtec.org (unknown [10.100.10.19]) by Websense Email Security Gateway with ESMTPS id 8BC41A452F0EF; Sat, 5 Mar 2016 01:06:02 +0000 (GMT) Received: from BAMAIL02.ba.imgtec.org (10.20.40.28) by HHMAIL01.hh.imgtec.org (10.100.10.19) with Microsoft SMTP Server (TLS) id 14.3.266.1; Sat, 5 Mar 2016 01:06:06 +0000 Received: from [10.20.3.92] (10.20.3.92) by bamail02.ba.imgtec.org (10.20.40.28) with Microsoft SMTP Server (TLS) id 14.3.266.1; Fri, 4 Mar 2016 17:06:04 -0800 Message-ID: <56DA30FC.10603@imgtec.com> Date: Fri, 4 Mar 2016 17:06:04 -0800 From: Leonid Yegoshin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Paul Burton CC: , Lars Persson , "stable # v4 . 1+" , "Steven J. Hill" , David Daney , Huacai Chen , Aneesh Kumar K.V , , Andrew Morton , Jerome Marchand , "Kirill A. Shutemov" , Ralf Baechle Subject: Re: [4/4] MIPS: Sync icache & dcache in set_pte_at References: <1456799879-14711-5-git-send-email-paul.burton@imgtec.com> <56D7A987.5040602@imgtec.com> <20160304103714.GA5576@NP-P-BURTON> <56D9F78E.6090303@imgtec.com> In-Reply-To: <56D9F78E.6090303@imgtec.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.20.3.92] Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 52459 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: Leonid.Yegoshin@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On Sat, Mar 05, 2016 at 12:21:54AM +0000, Paul Burton wrote: > > On Fri, Mar 04, 2016 at 07:02:24PM +0000, Lars Persson wrote: > > > Hi > > > > > > Some further thoughts on the matter. You have so far not showed a > > > valid example of a race condition. The two examples you give in the > > > commit message are for a _single_ thread existing in the address space > > > (fork and execve). > > > > Hi Lars, > > > > Neither fork nor exec are limited to a single thread existing in the > > address space - I'm not sure what you're saying? fork by its very > > definition results in 2. > > Ok, exec kinda is (it's late...). Still, fork clearly isn't. Again - fork doesn't copy any user page. Copy_page_range just manipulates PTE tree. So, no user page cache flushes are needed on MIPS during fork, at least now. - Leonid. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailapp01.imgtec.com ([195.59.15.196]:8804 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27008358AbcCEBGM1dohm (ORCPT ); Sat, 5 Mar 2016 02:06:12 +0100 Message-ID: <56DA30FC.10603@imgtec.com> Date: Fri, 4 Mar 2016 17:06:04 -0800 From: Leonid Yegoshin MIME-Version: 1.0 Subject: Re: [4/4] MIPS: Sync icache & dcache in set_pte_at References: <1456799879-14711-5-git-send-email-paul.burton@imgtec.com> <56D7A987.5040602@imgtec.com> <20160304103714.GA5576@NP-P-BURTON> <56D9F78E.6090303@imgtec.com> In-Reply-To: <56D9F78E.6090303@imgtec.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Paul Burton Cc: linux-mips@linux-mips.org, Lars Persson , "stable # v4 . 1+" , "Steven J. Hill" , David Daney , Huacai Chen , "Aneesh Kumar K.V" , linux-kernel@vger.kernel.org, Andrew Morton , Jerome Marchand , "Kirill A. Shutemov" , Ralf Baechle Message-ID: <20160305010604.Ao2Xm5WmW8er2Egdt1_5PBQTN4XB4CqIxPKzB5IEGiM@z> On Sat, Mar 05, 2016 at 12:21:54AM +0000, Paul Burton wrote: > > On Fri, Mar 04, 2016 at 07:02:24PM +0000, Lars Persson wrote: > > > Hi > > > > > > Some further thoughts on the matter. You have so far not showed a > > > valid example of a race condition. The two examples you give in the > > > commit message are for a _single_ thread existing in the address space > > > (fork and execve). > > > > Hi Lars, > > > > Neither fork nor exec are limited to a single thread existing in the > > address space - I'm not sure what you're saying? fork by its very > > definition results in 2. > > Ok, exec kinda is (it's late...). Still, fork clearly isn't. Again - fork doesn't copy any user page. Copy_page_range just manipulates PTE tree. So, no user page cache flushes are needed on MIPS during fork, at least now. - Leonid.