[patch] sched: fix scheduling latencies in vgacon.c

[Ingo Molnar]

this patch fixes scheduling latencies in vgacon_do_font_op(). The code
is protected by vga_lock already so it's safe to drop (and re-acquire)
the BKL.

has been tested in the -VP patchset.

	Ingo

this patch fixes scheduling latencies in vgacon_do_font_op(). The code
is protected by vga_lock already so it's safe to drop (and re-acquire)
the BKL.

has been tested in the -VP patchset.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

--- linux/drivers/video/console/vgacon.c.orig	
+++ linux/drivers/video/console/vgacon.c	
@@ -49,6 +49,7 @@
 #include <linux/spinlock.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
+#include <linux/smp_lock.h>
 #include <video/vga.h>
 #include <asm/io.h>
 
@@ -763,6 +764,7 @@ static int vgacon_do_font_op(struct vgas
 		charmap += 4 * cmapsz;
 #endif
 
+	unlock_kernel();
 	spin_lock_irq(&vga_lock);
 	/* First, the Sequencer */
 	vga_wseq(state->vgabase, VGA_SEQ_RESET, 0x1);
@@ -848,6 +850,7 @@ static int vgacon_do_font_op(struct vgas
 		vga_wattr(state->vgabase, VGA_AR_ENABLE_DISPLAY, 0);	
 	}
 	spin_unlock_irq(&vga_lock);
+	lock_kernel();
 	return 0;
 }