mm, proc: add KReclaimable to /proc/meminfo

The vmstat NR_KERNEL_MISC_RECLAIMABLE counter is for kernel non-slab
allocations that can be reclaimed via shrinker.  In /proc/meminfo, we can
show the sum of all reclaimable kernel allocations (including slab) as
"KReclaimable".  Add the same counter also to per-node meminfo under /sys

With this counter, users will have more complete information about kernel
memory usage.  Non-slab reclaimable pages (currently just the ION
allocator) will not be missing from /proc/meminfo, making users wonder
where part of their memory went.  More precisely, they already appear in
MemAvailable, but without the new counter, it's not obvious why the value
in MemAvailable doesn't fully correspond with the sum of other counters
participating in it.

Link: http://lkml.kernel.org/r/20180731090649.16028-6-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Vijayanand Jitta <vjitta@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 1ac4c36e13bb..86d6cd92ce3d 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -67,8 +67,11 @@ static ssize_t node_read_meminfo(struct device *dev,
         int nid = dev->id;
         struct pglist_data *pgdat = NODE_DATA(nid);
         struct sysinfo i;
+        unsigned long sreclaimable, sunreclaimable;
 
         si_meminfo_node(&i, nid);
+        sreclaimable = node_page_state(pgdat, NR_SLAB_RECLAIMABLE);
+        sunreclaimable = node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE);
         n = sprintf(buf,
                        "Node %d MemTotal:       %8lu kB\n"
                        "Node %d MemFree:        %8lu kB\n"
@@ -118,6 +121,7 @@ static ssize_t node_read_meminfo(struct device *dev,
                        "Node %d NFS_Unstable:   %8lu kB\n"
                        "Node %d Bounce:         %8lu kB\n"
                        "Node %d WritebackTmp:   %8lu kB\n"
+                       "Node %d KReclaimable:   %8lu kB\n"
                        "Node %d Slab:           %8lu kB\n"
                        "Node %d SReclaimable:   %8lu kB\n"
                        "Node %d SUnreclaim:     %8lu kB\n"
@@ -138,20 +142,21 @@ static ssize_t node_read_meminfo(struct device *dev,
                        nid, K(node_page_state(pgdat, NR_UNSTABLE_NFS)),
                        nid, K(sum_zone_node_page_state(nid, NR_BOUNCE)),
                        nid, K(node_page_state(pgdat, NR_WRITEBACK_TEMP)),
-                       nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE) +
-                              node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)),
-                       nid, K(node_page_state(pgdat, NR_SLAB_RECLAIMABLE)),
+                       nid, K(sreclaimable +
+                              node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE)),
+                       nid, K(sreclaimable + sunreclaimable),
+                       nid, K(sreclaimable),
+                       nid, K(sunreclaimable)
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
-                       nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)),
+                       ,
                        nid, K(node_page_state(pgdat, NR_ANON_THPS) *
                                        HPAGE_PMD_NR),
                        nid, K(node_page_state(pgdat, NR_SHMEM_THPS) *
                                        HPAGE_PMD_NR),
                        nid, K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED) *
-                                       HPAGE_PMD_NR));
-#else
-                       nid, K(node_page_state(pgdat, NR_SLAB_UNRECLAIMABLE)));
+                                       HPAGE_PMD_NR)
 #endif
+                       );
         n += hugetlb_report_node_meminfo(nid, buf + n);
         return n;
 }