From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932628AbVKXKOu (ORCPT ); Thu, 24 Nov 2005 05:14:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932629AbVKXKOu (ORCPT ); Thu, 24 Nov 2005 05:14:50 -0500 Received: from xproxy.gmail.com ([66.249.82.192]:57398 "EHLO xproxy.gmail.com") by vger.kernel.org with ESMTP id S932628AbVKXKOt (ORCPT ); Thu, 24 Nov 2005 05:14:49 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; b=UVEawQIss7WDo2YcTYdDYt+6fgi9+itnp5jAbPRKOZZeDTjWtbRI7r2Ma8iWsNZAka4aifD2D6BG59mCr9eCEwsjiSuT5Mb3DElo75gwbO/z+D9hPx9U+SCva4qoT6VM2HkfgjSMV0O5jq1YuWL1XbyL1UMlI9wtQ5v2I5YGdVo= Message-ID: <4385925F.8010108@gmail.com> Date: Thu, 24 Nov 2005 18:13:51 +0800 From: "Antonino A. Daplas" User-Agent: Thunderbird 1.5 (X11/20051025) MIME-Version: 1.0 To: linux-fbdev-devel@lists.sourceforge.net CC: Benjamin Herrenschmidt , Andrew Morton , Linux Kernel list Subject: Re: [Linux-fbdev-devel] Re: Console rotation problems References: <1132793150.26560.357.camel@gaston> <1132793556.26560.361.camel@gaston> <1132796831.26560.392.camel@gaston> <1132801542.26560.402.camel@gaston> <43855DBA.1050302@gmail.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Geert Uytterhoeven wrote: > On Thu, 24 Nov 2005, Antonino A. Daplas wrote: >> Benjamin Herrenschmidt wrote: >>> Remove bogus usage of test/set_bit() from fbcon rotation code and just >>> manipulate the bits directly. This fixes an oops on powerpc among others >>> and should be faster. Seems to work fine on the G5 here. >> Thanks, I reached a point when my head became muddled with bit >> manipulations, so I used arch-specific bitops but complete forgot >> that they were atomic :-) > > I haven't really looked at the rotation code, but I guess it can be optimized a > lot by using similar techniques like c2p (chunky-to-planar) conversions. > Actually, BenH's patch touched code that is in the slow path. The font rotation is done on the entire fontdata, then stored, on a console switch. Thus the rest of the drawing functions need not do repetitive and expensive bitmap rotation. Scrolling performance of a normally oriented and upside-down rotation is practically the same (1024x768 8x16 redraw). con_rotate = 0 real 0m2.550s user 0m0.000s sys 0m2.543s con_rotate = 2 real 0m2.559s user 0m0.001s sys 0m2.545s CCW and CW rotation, is of course slower, because the blit direction tends to be top->down, rather than left->right. con_rotate = 1 real 0m4.675s user 0m0.000s sys 0m4.663s con_rotate = 3 real 0m4.701s user 0m0.001s sys 0m4.684s Tony