From c38182a713df5268d8a4a33819a77f93b950f84c Mon Sep 17 00:00:00 2001 From: Marcin Slusarz Date: Wed, 15 Oct 2008 22:03:49 -0700 Subject: [PATCH] vgacon: optimize scrolling Join multiple scr_memcpyw into 1-3 calls (usually 2). (benchmarked average speedup: 1%) Signed-off-by: Marcin Slusarz Cc: Krzysztof Helt Cc: Antonino Daplas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/console/vgacon.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 6df29a6..3556268 100644 --- a/drivers/video/console/vgacon.c +++ b/drivers/video/console/vgacon.c @@ -292,23 +292,26 @@ 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) { + scr_memcpyw(d, vgacon_scrollback, count); + d += count; + } } 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; -- 1.8.2.3