Commit 61f94e18 authored by Vlastimil Babka's avatar Vlastimil Babka Committed by Linus Torvalds
Browse files

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: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarRoman 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: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b29940c1

Documentation/filesystems/proc.txt

+4 −0
Original line number Diff line number Diff line
@@ -858,6 +858,7 @@ Writeback: 0 kB 
AnonPages:      861800 kB

Mapped:         280372 kB

Shmem:             644 kB

KReclaimable:   168048 kB

Slab:           284364 kB

SReclaimable:   159856 kB

SUnreclaim:     124508 kB
@@ -925,6 +926,9 @@ AnonHugePages: Non-file backed huge pages mapped into userspace page tables 
ShmemHugePages: Memory used by shared memory (shmem) and tmpfs allocated

              with huge pages

ShmemPmdMapped: Shared memory mapped into userspace with huge pages

KReclaimable: Kernel allocations that the kernel will attempt to reclaim

              under memory pressure. Includes SReclaimable (below), and other

              direct allocations with a shrinker.

        Slab: in-kernel data structures cache

SReclaimable: Part of Slab, that might be reclaimed, such as caches

  SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure

drivers/base/node.c

+12 −7
Original line number Diff line number Diff line
@@ -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;

}

fs/proc/meminfo.c

+8 −8
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v) 
	long cached;

	long available;

	unsigned long pages[NR_LRU_LISTS];

	unsigned long sreclaimable, sunreclaim;

	int lru;



	si_meminfo(&i);
@@ -53,6 +54,8 @@ static int meminfo_proc_show(struct seq_file *m, void *v) 
		pages[lru] = global_node_page_state(NR_LRU_BASE + lru);



	available = si_mem_available();

	sreclaimable = global_node_page_state(NR_SLAB_RECLAIMABLE);

	sunreclaim = global_node_page_state(NR_SLAB_UNRECLAIMABLE);



	show_val_kb(m, "MemTotal:       ", i.totalram);

	show_val_kb(m, "MemFree:        ", i.freeram);
@@ -94,14 +97,11 @@ static int meminfo_proc_show(struct seq_file *m, void *v) 
	show_val_kb(m, "Mapped:         ",

		    global_node_page_state(NR_FILE_MAPPED));

	show_val_kb(m, "Shmem:          ", i.sharedram);

	show_val_kb(m, "Slab:           ",

		    global_node_page_state(NR_SLAB_RECLAIMABLE) +

		    global_node_page_state(NR_SLAB_UNRECLAIMABLE));



	show_val_kb(m, "SReclaimable:   ",

		    global_node_page_state(NR_SLAB_RECLAIMABLE));

	show_val_kb(m, "SUnreclaim:     ",

		    global_node_page_state(NR_SLAB_UNRECLAIMABLE));

	show_val_kb(m, "KReclaimable:   ", sreclaimable +

		    global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE));

	show_val_kb(m, "Slab:           ", sreclaimable + sunreclaim);

	show_val_kb(m, "SReclaimable:   ", sreclaimable);

	show_val_kb(m, "SUnreclaim:     ", sunreclaim);

	seq_printf(m, "KernelStack:    %8lu kB\n",

		   global_zone_page_state(NR_KERNEL_STACK_KB));

	show_val_kb(m, "PageTables:     ",

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