mm: print swapcache page count in show_swap_cache_info()

Every arch implements its own show_mem() function.  Most of them share
quite some code, some of them are completely identical.

This series implements a generic version of this function and migrates
almost all architectures to it.

This patch:

Most show_mem() implementations calculate the amount of pages within
the swapcache every time.  Move the output to a more appropriate place
and use the anyway available total_swapcache_pages variable.

Signed-off-by: Johannes Weiner <[email protected]>
Cc: Richard Henderson <[email protected]>
Cc: Ivan Kokshaysky <[email protected]>
Cc: Haavard Skinnemoen <[email protected]>
Cc: Bryan Wu <[email protected]>
Cc: Chris Zankel <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jeff Dike <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Paul Mundt <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Martin Schwidefsky <[email protected]>
Cc: David Howells <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Yoshinori Sato <[email protected]>
Cc: Ralf Baechle <[email protected]>
Cc: Greg Ungerer <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Hirokazu Takata <[email protected]>
Cc: Mikael Starvik <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

mm/swap_state.c

@@ -56,7 +56,8 @@ static struct {
 
 void show_swap_cache_info(void)
 {
-	printk("Swap cache: add %lu, delete %lu, find %lu/%lu\n",
+	printk("%lu pages in swap cache\n", total_swapcache_pages);
+	printk("Swap cache stats: add %lu, delete %lu, find %lu/%lu\n",
 		swap_cache_info.add_total, swap_cache_info.del_total,
 		swap_cache_info.find_success, swap_cache_info.find_total);
 	printk("Free swap  = %lukB\n", nr_swap_pages << (PAGE_SHIFT - 10));