From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcin Slusarz Subject: [PATCH 1/2] vgacon: optimize scrolling Date: Sun, 21 Sep 2008 18:00:08 +0200 Message-ID: <1222012809-5783-2-git-send-email-marcin.slusarz@gmail.com> References: <1222012809-5783-1-git-send-email-marcin.slusarz@gmail.com> Return-path: In-Reply-To: <1222012809-5783-1-git-send-email-marcin.slusarz@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LKML Cc: Antonino Daplas , linux-fbdev-devel@lists.sourceforge.net Join multiple scr_memcpyw into 1-3 calls (usually 2). (benchmarked average speedup: 1%) Signed-off-by: Marcin Slusarz Cc: Antonino Daplas Cc: linux-fbdev-devel@lists.sourceforge.net --- drivers/video/console/vgacon.c | 28 ++++++++++++++++------------ 1 files changed, 16 insertions(+), 12 deletions(-) diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index bd1f57b..de4f66c 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -292,23 +292,27 @@ static int vgacon_scrolldelta(struct vc_data *c, int lines) d = (void *) c->vc_origin; s = (void *) c->vc_screenbuf; - while (count--) { - scr_memcpyw(d, vgacon_scrollback + soff, c->vc_size_row); - d += c->vc_size_row; - soff += c->vc_size_row; - - if (soff >= vgacon_scrollback_size) - soff = 0; + if (count) { + int copysize; + count *= c->vc_size_row; + /* how much memory to end of buffer left? */ + copysize = min(count, vgacon_scrollback_size - soff); + scr_memcpyw(d, vgacon_scrollback + soff, copysize); + d += copysize; + count -= copysize; + + if (count) { + copysize = min(count, vgacon_scrollback_size); + scr_memcpyw(d, vgacon_scrollback, copysize); + d += copysize; + } } if (diff == c->vc_rows) { vgacon_cursor(c, CM_MOVE); } else { - while (diff--) { - scr_memcpyw(d, s, c->vc_size_row); - d += c->vc_size_row; - s += c->vc_size_row; - } + if (diff) + scr_memcpyw(d, s, diff * c->vc_size_row); } return 1; -- 1.5.6.4