From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932195AbVH3QM2 (ORCPT ); Tue, 30 Aug 2005 12:12:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932196AbVH3QM2 (ORCPT ); Tue, 30 Aug 2005 12:12:28 -0400 Received: from mailout11.sul.t-online.com ([194.25.134.85]:64689 "EHLO mailout11.sul.t-online.com") by vger.kernel.org with ESMTP id S932195AbVH3QM2 (ORCPT ); Tue, 30 Aug 2005 12:12:28 -0400 Message-ID: <43148610.70406@t-online.de> Date: Tue, 30 Aug 2005 18:15:12 +0200 From: Knut Petersen User-Agent: Mozilla/5.0 (X11; U; Linux i686; de-AT; rv:1.7.7) Gecko/20050414 X-Accept-Language: de, en MIME-Version: 1.0 To: Andrew Morton CC: "Antonino A. Daplas" , linux-fbdev-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Jochen Hein Subject: [PATCH 1/1 2.6.13] framebuffer: bit_putcs() optimization for 8x* fonts X-Enigmail-Version: 0.86.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-ID: JbQYSsZFYeDUcTmcVNMRCcSUcYTQoZh4ml8Pm40yD+79s3xqe25-sG@t-dialin.net X-TOI-MSGID: 9256a54a-3c6e-441d-815c-c45815219b3f Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This trivial patch gives a performance boost to the framebuffer console Constructing the bitmaps that are given to the bitblit functions of the framebuffer drivers is time consuming. Here we avoide a call to the slow fb_pad_aligned_buffer(). The patch replaces that call with a simple but much more efficient bytewise copy. The kernel spends a significant time at this place if you use 8x* fonts. Every pixel displayed on your screen is prepared here. Some benchmark results: Displaying a file of 2000 lines with 160 characters each takes 889 ms system time using cyblafb on my system (I´m using a 1280x1024 video mode, resulting in a 160x64 character console) Displaying the same file with the enclosed patch applied to 2.6.13 only takes 760 ms system time, saving 129 ms or 14.5%. Font widths other than 8 are not affected. The advantage and correctness of this patch should be obvious. Signed-off-by: Knut Petersen diff -uprN -X linux/Documentation/dontdiff -x '*.bak' -x '*.ctx' linuxorig/drivers/video/console/bitblit.c linux/drivers/video/console/bitblit.c --- linuxorig/drivers/video/console/bitblit.c 2005-08-29 01:41:01.000000000 +0200 +++ linux/drivers/video/console/bitblit.c 2005-08-30 17:19:57.000000000 +0200 @@ -114,7 +114,7 @@ static void bit_putcs(struct vc_data *vc unsigned int scan_align = info->pixmap.scan_align - 1; unsigned int buf_align = info->pixmap.buf_align - 1; unsigned int shift_low = 0, mod = vc->vc_font.width % 8; - unsigned int shift_high = 8, pitch, cnt, size, k; + unsigned int shift_high = 8, pitch, cnt, size, i, k; unsigned int idx = vc->vc_font.width >> 3; unsigned int attribute = get_attribute(info, scr_readw(s)); struct fb_image image; @@ -175,7 +175,11 @@ static void bit_putcs(struct vc_data *vc src = buf; } - fb_pad_aligned_buffer(dst, pitch, src, idx, image.height); + if (idx == 1) + for(i=0; i < image.height; i++) + dst[pitch*i] = src[i]; + else + fb_pad_aligned_buffer(dst, pitch, src, idx, image.height); dst += width; } }