From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750829AbVHQFKj (ORCPT ); Wed, 17 Aug 2005 01:10:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750855AbVHQFKj (ORCPT ); Wed, 17 Aug 2005 01:10:39 -0400 Received: from wproxy.gmail.com ([64.233.184.192]:33548 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S1750829AbVHQFKi convert rfc822-to-8bit (ORCPT ); Wed, 17 Aug 2005 01:10:38 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=seBXNOC0EGNDmaICPmSkbqXZGV2xYMkZy//DGgVtKffgWye74iVpP/7Yo3nOX/jnMrs3w2bz3e+bKkK6hIVA/eMh69kqeNK7DErykvlAKWHpBUvUSB3bvU/DibzdSCHtRHy5luRTmcXwy3o+JJ0gWjkDv6XuiXNcEhJVD/t/8MA= Message-ID: <98df96d305081622107ca969f@mail.gmail.com> Date: Wed, 17 Aug 2005 14:10:34 +0900 From: Hiro Yoshioka Reply-To: hyoshiok@miraclelinux.com To: Akira Tsukamoto Subject: Re: [RFC] [PATCH] cache pollution aware __copy_from_user_ll() Cc: arjan@infradead.org, linux-kernel@vger.kernel.org In-Reply-To: <20050817.110503.97359275.taka@valinux.co.jp> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <98df96d3050815163331d6cce1@mail.gmail.com> <20050816.123042.424254477.hyoshiok@miraclelinux.com> <1124171390.3215.8.camel@laptopd505.fenrus.org> <20050817.110503.97359275.taka@valinux.co.jp> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Akira, Thanks for your suggestions. On 8/17/05, Akira Tsukamoto wrote: > Anyway, going back to copy_user topic, > big remaining issues are > 1)store/restore floating point register (80/64bytes) twice every time by > surrounding with kernel_fpu_begin()/kernel_fpu_end() is big penalty I don't know. If nobody uses MMX/XMM, then there is no need to save and restore. > 2)after pagefault not always come back to copy function and corrupts fp register I'm trying to understand this mechanism but I don't understand very well. > 3)disabling long preemption > Please correct me if I am wrong. > > I tried to implement fpsave inside pagefault handler once and here is my junk; > http://www.suna-asobi.com/~akira-t/linux/k7-copy-user/K7-copy_47_with_fpusave_not_finished.patch > never had a time to finish it. Hiro, does it help you? Thanks. I'm reading your patch but could not understand very well. I'll ask you. Regards, Hiro -- Hiro Yoshioka mailto:hyoshiok at miraclelinux.com