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| author | Marcin Slusarz <marcin.slusarz@gmail.com> | 2008-10-15 22:03:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-16 11:21:45 -0700 |
| commit | c38182a713df5268d8a4a33819a77f93b950f84c (patch) | |
| tree | 5c19e8bb3ad02ba9fa0bc6435b0ff626af2ac06a /drivers/video | |
| parent | 1a3b09dc9aeaaab25ff736c2443df423a8fb655e (diff) | |
| download | linux-c38182a713df5268d8a4a33819a77f93b950f84c.tar.bz2 | |
vgacon: optimize scrolling
Join multiple scr_memcpyw into 1-3 calls (usually 2). (benchmarked
average speedup: 1%)
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video')
| -rw-r--r-- | drivers/video/console/vgacon.c | 27 |
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/video/console/vgacon.c b/drivers/video/console/vgacon.c index 6df29a62d720..3556268fe0a0 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; |