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Commit c38182a7 authored by Marcin Slusarz's avatar Marcin Slusarz Committed by Linus Torvalds
Browse files

vgacon: optimize scrolling 



Join multiple scr_memcpyw into 1-3 calls (usually 2).  (benchmarked
average speedup: 1%)

Signed-off-by: default avatarMarcin Slusarz <marcin.slusarz@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Cc: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 1a3b09dc

drivers/video/console/vgacon.c

+15 −12
Original line number Diff line number Diff line
@@ -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 (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 (soff >= vgacon_scrollback_size)

			soff = 0;

		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;