mm: show quicklist usage in /proc/meminfo

Quicklists can consume several GB of memory.  We should provide a means of
monitoring this.

After this patch is applied, /proc/meminfo will output the following:

% cat /proc/meminfo

MemTotal:      7715392 kB
MemFree:       5401600 kB
Buffers:         80384 kB
Cached:         300800 kB
SwapCached:          0 kB
Active:         235584 kB
Inactive:       262656 kB
SwapTotal:     2031488 kB
SwapFree:      2031488 kB
Dirty:            3520 kB
Writeback:           0 kB
AnonPages:      117696 kB
Mapped:          38528 kB
Slab:          1589952 kB
SReclaimable:    23104 kB
SUnreclaim:    1566848 kB
PageTables:      14656 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
WritebackTmp:        0 kB
CommitLimit:   5889152 kB
Committed_AS:   393152 kB
VmallocTotal: 17592177655808 kB
VmallocUsed:     29056 kB
VmallocChunk: 17592177626432 kB
Quicklists:     130944 kB
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
HugePages_Surp:      0
Hugepagesize:    262144 kB

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Keiichiro Tokunaga <tokunaga.keiich@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/proc_misc.c

@@ -24,6 +24,7 @@
 #include <linux/tty.h>
 #include <linux/string.h>
 #include <linux/mman.h>
+#include <linux/quicklist.h>
 #include <linux/proc_fs.h>
 #include <linux/ioport.h>
 #include <linux/mm.h>
@@ -189,7 +190,8 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
 		"Committed_AS: %8lu kB\n"
 		"VmallocTotal: %8lu kB\n"
 		"VmallocUsed:  %8lu kB\n"
-		"VmallocChunk: %8lu kB\n",
+		"VmallocChunk: %8lu kB\n"
+		"Quicklists:   %8lu kB\n",
 		K(i.totalram),
 		K(i.freeram),
 		K(i.bufferram),
@@ -221,7 +223,8 @@ static int meminfo_read_proc(char *page, char **start, off_t off,
 		K(committed),
 		(unsigned long)VMALLOC_TOTAL >> 10,
 		vmi.used >> 10,
-		vmi.largest_chunk >> 10
+		vmi.largest_chunk >> 10,
+		K(quicklist_total_size())
 		);
 
 		len += hugetlb_report_meminfo(page + len);

include/linux/quicklist.h

@@ -80,6 +80,13 @@ void quicklist_trim(int nr, void (*dtor)(void *),
 
 unsigned long quicklist_total_size(void);
 
+#else
+
+static inline unsigned long quicklist_total_size(void)
+{
+	return 0;
+}
+
 #endif
 
 #endif /* LINUX_QUICKLIST_H */